Useful Notes / Stock Dinosaurs (Saurischian Dinosaurs)

Saurischian Pelvis

This page is about the stock Saurischian dinosaurs. Saurischian ("lizard-hipped" dinosaurs) included both the Theropods, the bipedal usually carnivorous dinosaurs which gave birth to true birds, and the Sauropods, the quadrupedal herbivorous dinosaurs with long necks that got extinct 66 mya in the Mass Extinction. Both lineages arose in the Triassic. Some kinds are, or were, uncertain if really belonged to the Saurischians, and the group itself is debated: some think (or have thought in the past) that theropods, or alternatively sauropods, were actually closer to Ornithischians than to the other subgroup of Saurischians. The image of the saurischian pelvis is above.

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Bipedal Meat-Eaters (usually)

Most dinosaurs were herbivorous or omnivorous; the Theropod group contains all the carnivorous dinosaurs. Some of them were very small, while the biggest weighed as much as an elephant or a bit more, and were taller and longer than a modern elephant. Their legs were birdlike in structure; their feet had three main toes and usually a smaller reversed fourth toe. They were all bipedal; some had only tiny rudimentary forelimbs, like the tyrannosaurids. Theropods are the only group of dinosaurs that has living members today, since they included the common ancestor of birds. Some close-to-bird theropods became omnivores and sometimes herbivores; the group includes the only toothless non-bird-dinosaurs. Many theropods are now known to have been feathered, but in films they are usually shown with lizard-like scales, while documentaries tend to be a bit wonky on the coverings of their theropods.

Great-Stock Theropods

The King of the Cretaceous: Tyrannosaurus ***

King Tyrant Lizard

Lived in western North America, between Alberta and Utah, and possibly as far south as Texas, 68-66 mya at the very end of the Age of Dinosaurs. Other tyrannosaurs lived in Asia in the same period, and other members of the tyrannosaurid family lived slightly earlier, still within the Late Cretaceous Period, in North America. Asian remains attributed to T. rex are fragmentary and almost certainly didn't belong to it. Together with Triceratops and few others, Tyrannosaurus was one of the rare dinosaurs that was directly led to extinction by the asteroid/comet collision at the end of the Mesozoic Era.

T. rex was discovered by Barnum Brown shortly before the start of the 20th century, and described by Henry Fairfield Osborn in 1905. Since then, it has been a hit with the audience and possibly the most famous dinosaur for almost a century thanks to its long-held status as the largest carnivorous dinosaur (before it eventually got overtaken). During this time depictions of the "rex" have changed from the heavy, fat-bellied giant with goose-like gait and flexible tail seen in Fantasia to the slender, running beast seen in Jurassic Park. We have long waited to see it, or at least its chicks, depicted with feathers - although later studies have seemingly concluded that large tyrannosaurids would have been primarily scaly (any feathering would have been in the dorsal region) - presumably having secondarily lost or at least reduced their feathers. This idea began seeping into pop-consciousness in The New '10s, through works like Dinosaur Revolution, Dinosaur Island (2014), Pokémon, Mighty Magiswords, Saurian, and Doraemon.

Despite only living for a couple of million years in a small part of the world, almost every visit to a dinosaur-populated time or place will have at least one T. rex appearing. Yes, that's how big it is in media. For more scientifically accurate information on the animal, see its own Useful Notes page.

1. Entry Time: 1905
2. Trope Maker: Itself

Sickle-Footed Trio: Deinonychus, Velociraptor & Utahraptor ***

Mongolian Swift Thief & Counterbalanced Terrible Claw

Raptors, or more formally dromaeosaurids, were bipedal carnivorous dinosaurs of the Cretaceous Period. They were small with long, thin tails and compact bodies. They were closely related to birds: their skeletal structure was bird-like, and since the late 1990s it has been proven they were also covered with pennaceous feathers.

The most distinctive feature, however, was the large "sickle claw" on their second toe. It was a very specialized tool, and has also been compared with the saber-toothed cats' fangs. The toe bearing it was very shortened and strong compared with the other two main toes. When walking and running, dromaeosaurids kept their second toe raised up to the ground level, so the whole weight of their body was sustained by only two digits of each hindlimb. The sickle-toes were moved by powerful muscles and tendons; scientists think "raptors" were able to lower them when used as weapons, just like cats do with their retractable claws. How it was used is being still debated. For decades, dromaeosaurids were depicted as hunting and attacking herbivores much bigger than itself, e.g. the classic Deinonychus hunting Tenontosaurus or even the five-ton Iguanodon. Like a pack of wolves, dromaeosaurids were envisioned attack their prey en masse, using their powerful claws to rend and to climb atop the herbivore. Since around the Turn of the Millennium, dromaeosaurids have instead been suggested to have been mostly solitary hunters, taking prey the same size or larger than themselves, but leaving the very large ornithopods or sauropods alone.

In the early 20th century, two small dinosaurs were discovered and described as generic small predators. Both were from the Late Cretaceous. While the finds were incomplete and difficult to interpret, we now know the animals were about 6.5ft/2m long and weighed about 33 lb./15 kg. Dromaeosaurus albertensis ("Alberta's running lizard") lived in the Alberta region, while Velociraptor mongoliensis ("Mongolian swift robber") lived in Mongolia and northern China 75-71 mya. For half a century, they were sorted away and largely ignored. Then...

Deinonychus ^note  pronounced either dy-NON-i-kəs or dy-no-NIKE-əs ("terrible claw") was discovered in 1964. It lived 115-108 mya in Early Cretaceous North America and was at the same time one of the largest and one of the earliest raptors, 11ft/3.4m long and weighing 160 lb./73 kg. Even though some illustrations showed it as tall as an adult man, it would actually only reach his hips if alive today. Some years later, more complete remains of Velociraptor were found, showing that it was similar to Deinonychus but even smaller: the weight of a large turkey.

Deinonychus antirrhopus was described by John Ostrom in 1969 in an influential monograph that kicked off the "Dinosaur Renaissance". After that, paleontologists, especially Ostrom's pupil Bob Bakker, began to debate if the traits ascribed to Deinonychus (agility, smartness, warm-bloodedness, social behavior) should be extended to all dromaeosaurids, or possibly to all theropods, or even to all dinosaurs. This debate continues still today.

In the 1980s, one paleontologist (Gregory Paul) claimed that Deinonychus and Velociraptor were actually the same genus and that the species Deinonychus antirrhopus should be renamed "Velociraptor antirrhopus"; author Michael Crichton picked up this idea, showing both Deinonychus and Velociraptor proper in his Jurassic Park novel as distinct species within one single genus, "Velociraptor". "Velociraptor antirrhopus", aka Deinonychus, is the main "raptor" in the story, while Velociraptor mongoliensis itself appears only in the shape of newborns. Being bigger and more menacing for humans, Deinonychus was the one chosen for the bad guy role, even though it's possible Crichton chose to name it Velociraptor just because he thought this name is cooler-sounding.

Works from before the 1970s never represent dromaeosaurids, simply because they were scientifically too obscure at the time. For example, Disney's Fantasia made in 1940 doesn't show them at all. Significantly, between 1970 and the Jurassic Park mania in the 1990s, the most represented "raptor" (though not yet known by that term) in popular culture was Deinonychus itself, while the less-impressive Velociraptor was unknown to laymen, not counting the antecedent dino-fans. For instance, see the franchise Dino-Riders, the novel Carnosaur and the subsequent film, the Rune Quest Borderlands tabletop RPG adventure, or even the Dutch metal-band named Deinonychus. It was Jurassic Park that apparently caused Velociraptor to displace Deinonychus as the stock sickle-clawed dino (documentary media started showing the "veloci" more often thanks to the film), and started the usage of "raptor" for dromaeosaurid in the mind of the public — prior to this, "raptor" was used only to indicate Noble Bird of Prey. There are several issues with the depiction of raptors in the film.

How can we really tell Deinonychus apart from Velociraptor? Other than their different size, this can simply be done by observing their skull. The Deinonychus head was relatively stocky, with a convex profile and the snout ending with a thin point; the Velociraptor head was narrower and more elongated, with a concave profile and a blunt snout. If you watch carefully the head of the Jurassic Park "raptors", you'll note it's modelled upon the robust skull of Deinonychus. This would demonstrate the latter is the actual animal people think when they think "Velociraptor". However, the JP Deinonychuses have also exaggeratedly fleshy lips and too large eyes compared with the more realistic portraits of the Deinonychus in dino-books; these two modifications actually make their heads looking like a cross between a Deinonychus and a Velociraptor. About Utahraptor, this one cannot have been the inspirer of the JP critters despite being the most similar to them if you count the overall size of the body, both because the Utahraptor's skull was not still found at the time apart from the very end of the snout, and because this dinosaur was described slightly after the production of the first movie.

Utahraptor ostrommaysi (originally called Utahraptor ostrommaysorum) was first discovered in Utah at the same time that the name Velociraptor became popular thanks to the original film Jurassic Park, in the early Nineties. This animal was even larger and slightly older than Deinonychus, living 135-130 mya and being 23ft/7m long and as tall as a human. Its naming in year 1993 began an awesome case of science culture Ascended Fanon (or inverted Pop-Cultural Osmosis if you prefer): before Jurassic Park, no genus of dromaeosaurids except Velociraptor had the -raptor suffix to its name. Since the film, paleontologists started to use it for naming most new dromaeosaurids.

Despite the scantiness of its original remain, the discovery of Utahraptor was much reported in media as it incidentally matched the size of the oversized JP raptors, or rather, was even longer than they were. Many then reported the Utahraptor as "the most fearsome killing-machines of all times", capable of killing, in packs, the biggest sauropods and even of destroying entire dinosaur species. However, Walking with Dinosaurs was not so extreme, showing Utahraptor hunting successfully the relatively smaller Iguanodon in group — not in Utah but in Europe for some reason. In the later Jurassic Fight Club it is seen battling alone the even smaller but more protected ankylosaurian Gastonia, this time losing the fight. Sadly, both shows portray the animal featherless, with a wrong Deinonychus-like head, and even with backward-pointing hands. Utahraptor has proven to have been a different and more specialized animal than what is shown in the traditional depictions: new remains reveal it to have had stumpy arms, a short tail, short, robust legs and a unique dentition, similar to animals like Masiakasaurus. What exactly this new look entails for the behavior and ecology of Utahraptor, as of now, remains uncertain.

The genus of Asian dromaeosaurid named Velociraptor was first-found in Asia in the 1920s together with the similarly-named Oviraptor; before the production of the first film of the franchise in 1993 the dinosaur was basically portrayed only in popular dinosaur books (unlike the already fictionally portrayed Deinonychus, see Dino-Riders for an example of Deinonychus from The '80s): but the proper Velociraptor was already frequent in docu-media before JP, mainly thanks to an exceptional and (rightly) still-today celebrated finding made in The '70s in Mongolia: a specimen of the animal dead while grabbing the small herbivorous ceratopsian Protoceratops with its limbs. The fossil of this specimen of Velociraptor is also particularly complete, with a lying-down body, the tail held rigid and pointing backwards, the head unusually not curved backwards but forwards (averting the so-called death pose extremely common in other dinosaur fossil skeletons, especially of theropods), the "hands" grasping the other dinosaur's head, and one of its pedal sickle-talons into the neck of its victim. So, in classic dino-illustrations, the dinosaur is very often shown battling a Protoceratops and dying clutched together with it in several manners: buried by a sandstorm, stuck in mud or in quicksand, falling from a cliff, etc. according to the artist. On the other hand, the iconic battle between the two animals has strangely yet to appear in films or stories and in TV programs (except for of course the documentaries, like the 1993 Planet of Dinosaurs).

Speaking of Misplaced Wildlife, you can expect any of these three dromaeosaurids to be placed in the same habitat as at least Tyrannosaurus and Triceratops. In reality, Deinonychus and Utahraptor were already extinct by the time T. rex came along and Velociraptor lived on the other side of the planet. However, this inaccuracy was vindicated somewhat by the discovery of Acheroraptor (described in 2013) and Dakotaraptor (described in 2015), which greatly resembled Velociraptor and Deinonychus respectively, and the latter was roughly the size of Utahraptor.

According to the researches of The New '10s, raptor hunting tactics did not involve high-speed pursuits or using the claws to disembowel prey. What they did involve, however, was a ridiculous amount of Nightmare Fuel. Dromaeosaurs could only run at about 45 miles/hour for the faster species (Deinonychus and Velociraptor) and 20 miles per hour for the larger, more robust Utahraptor (this is still faster than any human), but they had Super-Reflexes and superb Combat Parkour skills, able to leap, flip, dodge, and accelerate with ease. They were good climbers, and their feathered wings probably helped them control their falls as well as muffling sound. The talons provided a near-unbreakable grip, and were used as grappling devices and stabbing weapons. Recent research into their eye sockets proved they had superb vision and were able to see very well in the dead of night, which was when they would use Jump Scare tactics to sneak up on unwary prey. Put together, they provide a picture of an agile, stealthy, powerful hunter stalking victims at night from the treetops, completely silent and invisible, before leaping in as Death from Above, dodging counterattacks using Combat Parkour, latching on with a formidable grip, and either stabbing the prey in the neck or pinning it down and eating it alive as it writhed in agony.

1. Entry Time: 1970s/1980s/1990s/2000s
2. Trope Maker: The "Dinosaur Renaissance" and the works inspired from it. Specifically, Deinonychus in the 1980s Dino-Riders and other works, Utahraptor in the 1990s Raptor Red (a scientific novel), and the true Velociraptor in the 2000s Disney's Dinosaur (though Jurassic Park had already made the name famous beforehand)

The King of the Jurassic: Allosaurus ***

Fragile Different Lizard

Allosaurus lived 155 to 150 million years ago in North America, with some additional fossils found in Europe and maybe Africa. Along with Tyrannosaurus, it has traditionally been the large carnivorous dinosaur. Allosaurus is the scientifically most well-known large theropod: dozens of specimens have been found so far in Western USA, including a veritable "graveyard" in the Cleveland-Lloyd Dinosaur Quarry (Utah). At the time, there was a swamp where the "graveyard" is today: Allosauruses were attracted by the carrion of giant herbivores and got stuck in the mud as well. Many young individuals are also known, but not nests or hatchlings.

First discovered in 1877 during the Bone Wars, Allosaurus literally means "other lizard" or "strange lizard", but Othniel Charles Marsh's article naming it gives no reason for the bland choice. The most well-known species is Allosaurus fragilis ("the other fragile lizard"); some fragmentary remains of unusually large size are often classified in separate genera (see Prehistoric Life), such as Saurophagnax or Epanterias. Some scanty fossils from Early Cretaceous Australia used to be classified as a small-sized late-surviving Allosaurus species, but were reclassified in 2009 as a totally different theropod, Australovenator. Even scantier remains were found in the USA before Allosaurus was officially described in 1877; they were labeled Antrodemus, but possibly belong to Allosaurus as well. If true, the former might become the valid name for this dinosaur (the name "Antrodemus" appears sometimes in old dinosaur books instead of "Allosaurus").

Allosaurus was the top predator in the Late Jurassic, sometimes referred as "the T. rex of the Jurassic" (although they're not actually related). Its hunting behavior is still uncertain: we're not sure if it was mainly a pack-hunter or a solitary ambush-predator. In documentaries and pop-books it usually appears as a pack-hunter capable of bringing down the biggest sauropods like Diplodocus, like in the memorable The Ballad of Big Al, Apatosaurus, or even Brachiosaurus. Alternatively, it is shown in a battle against the armored Stegosaurus (the Jurassic equivalent of the Tyrannosaurus-vs-Triceratops Cretaceous duel). All this might be Truth in Television since all these animals lived together in North America in the same period, but more probably Allosaurus more often hunted easier prey such as young sauropods, young stegosaurs, and ornithopods like Camptosaurus, because its jaws and teeth were less-powerful than those of the tyrannosaurs. There are stegosaur and sauropod fossils showing Allosaurus bite marks and Allosaurus fossils that show wounds created by stegosaur tails, showing that allosaurs could have been predators as powerful as the more evolved tyrannosaurs.

Allosaurus entered pop culture before Tyrannosaurus rex. After its description, it was briefly considered the "biggest land carnivore ever" together with Megalosaurus. In Conan Doyle’s The Lost World (1912) the two scientists encounter a giant carnivore, and argue about whether it is an Allosaurus or a Megalosaurus, maybe a reference to the then-recent Bone Wars. Soon afterward, both dinosaurs got overshadowed by the more impressive (and much cooler-named) Tyrannosaurus in pop-media, especially cinema. Allosaurus has somehow managed to survive the supremacy of the rex... automatically becoming its Poor Man's Substitute, as the two animals tend to be easily confused with each other in the public mind. However, Allosaurus is still probably the second-most-portrayed large theropod in popular culture after Tyrannosaurus. If a writer is telling a story set in the Jurassic period instead of the Cretaceous and wants to be accurate, typically this is the theropod they'll use.

Allosaurus is rather easy to distinguish from T. rex if watched carefully. It was generally smaller (the classic species was slightly shorter and about one half of the weight of a T. rex), had shorter legs, a longer tail, slimmer body, longer neck, narrower head, weaker lower jaw, smaller teeth, and a pair of "bosses" in front of its eyes (maybe covered in keratin in Real Life, making them like small "horns"). Above all, it had longer front arms with three clawed fingers rather than two. Sadly, all these differences tend to be glossed over in popular media. The fact that T. rex itself has often been depicted with long arms with three functional digits (e.g. in Disney's Fantasia) doesn't help, either.

Among the official Allosaurus appearances in cinema, the Ray Harryhausen ones are the most remembered. The allosaur is the go-to Big Bad of his movies, appearing in One Million Years BC and playing the role of Gwangi in The Valley of Gwangi. Ray's critters looked just like that of Fantasia, with the same mishmash of allosaur and tyrannosaur features (and with the same outdated erect body, serpentine tail and goose-gait); the only difference is that Harryhausen's theropods have Evil Eyebrows — this may be forgivable for some, considering the aforementioned eye bosses which could have given to it a "fierce look" like an eagle.

1. Entry Time: 1880s/1890s
2. Trope Maker: Recorded status as largest meat-eater at time & The Lost World (1912)

Big Predatory Theropods

Since The '90s, a handful of large theropods have started to filter into pop-consciousness, often after a single remarkable appearance in Movieland: Spinosaurus (Jurassic Park III), Baryonyx (Ice Age: Dawn of the Dinosaurs), Giganotosaurus (Primeval), Carnotaurus (Disney's Dinosaur), some non-rex tyrannosaurs (Albertosaurus, Gorgosaurus, Tarbosaurus), and Dilophosaurus (the original Jurassic Park, of course). Despite having often some cool traits, like crests, horns, claws, or sheer size, none of them has managed to replace T. rex as the "King of the Dinosaurs" — at least for now. Ceratosaurus entered pop-culture around the same time of T. rex and Allosaurus, while Megalosaurus entered it much earlier, in the XIX century.

Spiny-backed Fish-tailed Colossus: Spinosaurus **

Egyptian Spine Lizard

Lived in Northern Africa 100-93 mya, during the Cretaceous Period. At present, this is the biggest theropod; no other matches it in bulk, length and weight.

Spinosaurus aegyptiacus means "Egyptian spiny lizard": it has always been one of the most recognizable theropods with its 7ft/2.1m tall spines on its back. In the most common interpretation the spines form a "sail" similar to that of the non-dinosaur Dimetrodon. Some suggest that they instead supported a fleshy hump or a ridge, while others thought they came from another dinosaur altogether. A sail could have been useful as a thermoregulating device to prevent overheating and/or as a display tool (like Stegosaurus plates), and a ridge could have been for display, making the animal seem larger, as well as storing extra energy gained from the giant fish and other prey that Spinosaurus fed on.

Spinosaurus was first described in 1915 by a German paleontologist, but its remains were very scanty: its skull was incomplete, and as we didn't have limb bones, the fossil-hunter gave to it four fingers for each hand instead of three. The best spinosaur find was stored in a German museum, which was destroyed by accident during an aerial bombing in World War II. In older drawings Spinosaurus had a head and body like a generic "large theropod"; since the last XX century it has generally been accepted that its head was similar to a crocodile's. Due to the fragmentary nature of its remains, the actual overall size has been in debate; it was traditionally thought the same length and height of an average Tyrannosaurus (40ft/12m long and 20ft/6m high) but lighter-weighing (4 tons instead of 6 tons of the rex); but many paleontologists wanted to set the length at 50ft/15m. Lack of real evidence for this left T. rex with the official record size until the discovery of Giganotosaurus in the mid-1990s. At the same time, further discoveries confirmed that Spinosaurus really was bigger than Tyrannosaurus rex, and indeed the biggest of the lot.

Despite this, the spinosaur remained a "nonfiction-only" dinosaur. Then, in the year 2001... Jurassic Park III changed this situation in a blink. This film introduced the spinosaur to the audience as "bigger and badder" than a Tyrannosaurus rex, and easily capable of defeating the latter in a fight. This was the start of the Spinosaurus Versus T. rex trope in media.

There has always been controversy regarding Spinosaurus’ diet and way-of-life: did it prey on fish like its smaller cousin Baryonyx (see below), or on giant herbivores like Tyrannosaurus did? Experts tended to prefer the first option at the time Jurassic Park III was produced, and this fostered even more criticism about the film portrayal as the Ultimate Superpredator. In The New '10s Spinosaurus's lifestyle was generally believed to have been midway between these two extremes: an opportunist like a giant, clawed, saltwater crocodile, attacking other smaller dinosaurs when given the opportunity, as well as eating giant fish (including sharks, 5-meter coelacanths, and enormous lungfish) and possibly crocodiles, a feat requiring tremendous levels of strength, and using its size to steal kills from other predators. Experts were unsure about the latter, though: Carcharodontosaurus was specially adapted to big-game hunting and could open its jaws very wide to inflict severe slicing cuts, which could likely cause the spinosaur to bleed to death if the two fought. Spinosaurus' large size would, however, have made it a hard target to bite for other predators.

But the surprise was already hidden in the Saharan rocks: in 2014, Spinosaurus received an almost-total makeover after new fossils were discovered there. In addition to tiny pores in its skull that might have enabled it to sense underwater prey (which was already known by then), Spinosaurus also had a relatively small pelvis and short hind legs with flat — possibly webbed — hind feet, among other adaptations for a semiaquatic lifestyle — all in all showing a surprising degree of convergent evolution with the ancestors of modern whales. Unrelated to its amphibious makeover, its reconstruction also gives it a dip in the middle of its dorsal spines similar to that of its relative Ichthyovenator. It has been suggested that the hind limbs were scaled incorrectly but then the people who made the discoveries have responded putting these supposed corrections to doubt. Also, the tall spine on the sail might have actually been located further back on the body thus forming a more shallow and gradual version of the "classic" Spinosaurus sail^note The authors of the 2014 reconstruction never gave a reason why they thought the sail was shaped that way., although this too is debatable. Finally, it has been suggested that Spinosaurus held its neck vertically rather than horizontally. This would have shifted the center of gravity back and allow Spinosaurus to walk bipedally most likely similar to a duck: Spinosaurus' forelimbs and shoulders seem to lack the weight-bearing adaptations needed for quadrupedal movement.

Not all scientists were convinced, however, and a 2018 study has been released suggesting that, rather than being a full time swimmer, Spinosaurus spent most of its time wading along the shore and hunting fish in shallow water, more like a giant heron or stork. However, this study is not without a few issues, namely giving the tested Spinosaurus models with a narrower torso due to basing it on reconstructions seen in lateral view.

Finally, a new fossil discovered in 2020 revealed that Spinosaurus had a paddle-shaped tail, demonstrating that, yes, it was truly aquatic. Given that it inhabited the tidal reaches of a coastal swamp, Spinosaurus was arguably also the only marine non-avian dinosaur.

And then, in 2021, another study changed our view of Spinosaurus even more. According to this study, while Spinosaurus was indeed aquatic, it was not an especially strong swimmer; the paddle-shaped tail was more likely for display. Instead of actively swimming, it would have used its short legs to "punt" itself along underwater, the same way hippos do today. However, as the previous discoveries have shown us, this probably isn't the last news we'll hear of our old friend Spinosaurus.

NOTE: The picture above of Spinosaurus is not updated anymore due to Science Marches On. It is based upon the 1990s-2000s-early 2010s commonly-accepted vision of the animal, with round sail on its back, the long hindlegs of a normal theropod, and non-flattened tail.

1. Entry Time: 2001
2. Trope Maker: Jurassic Park III

Heavy-clawed Bipedal Crocodile: Baryonyx **

Walker's Heavy Claw

This is a cousin of Spinosaurus that lived in Europe in the Early Cretaceous, 130-125 mya, alongside Iguanodon. Discovered in 1983 in Southern England and named in 1986 by A. Charig & A. Milner, its find got massive media coverage at the time, to the point it was qualified by some as "the greatest European dino-find of the XX century"; in part because, being 30ft/9m long, Baryonyx was the largest and most complete European giant theropod, but mostly because it was very different from other dinosaurs known at the time, with its crocodile-like jaws lined with an incredible 96 teeth (T. rex and Allosaurus had no more than 75 teeth). The skull also shows similarities to that of the early Coelophysis and Dilophosaurus, ex. the undulating edge of the upper jaw: so, one scientist thought the Baryonyx was a gigantic Cretaceous descendant of them. Others thought it was somewhat close to dromaeosaurs, because of its very special forelimbs.

Baryonyx means "heavy claw" and the animal has been nicknamed Claws by the press (a reference to the famous film Jaws of 1975) because of its 10-inch/25-cm hook-like thumb-claws, bigger than the other two fingers on each hand. We don't know if Spinosaurus had these hook hands as well. Baryonyx’s forelimbs were longer and stronger than in most other theropods, but the structure of the forefeet seems to preclude quadrupedal walking (contrary to what has traditionally been shown in illustrations); it is speculated, however, that Baryonyx might have fed by resting on its front legs on a riverbank and sweeping large fish such as the carp-like Lepidotes from the river with its powerful claw, a bit like grizzly bears do with salmon. We know for sure fish were included in its diet: scales of Lepidotes were found inside the ribcage of the original (and only sure) Baryonyx specimen, named B. walkeri from his first discoverer: an English amateur fossil collector, William Walker, who first found the isolated thumbclaw of the animal jutting from the rocks like a spur (only one claw was found). Alan Charig and Angela Milner then found the remaining incomplete skeleton, and described it officially three years after.

Baryonyx was the first discovered fish-eater among dinosaurs, and several traits scientists assigned to Spinosaurus were initially based on Baryonyx. Together, these dinosaurs (plus few others) form the spinosaurid family. However, "Claws" was quite different from Spinosaurus: it had no sail on its back — however, its relative Suchomimus did have a sail, though much shorter than that of Spinosaurus — and was considerably smaller (10 m long and weighing 2 tons, like an Allosaurus). Its head was thinner with a small bump on its top and gharial-like jaws with twice the teeth of most other theropods. Baryonyx was traditionally believed more aquatic than Spinosaurus: fish might have made a great part of its diet, possibly with occasional carrion and small land animals as a supplement (the remains of a juvenile Iguanodon were found in the original specimen's gut). Its short hind-legs show it was not an especially fast runner; moreover, its blunt croc-like teeth and weak thin jaws probably prevented the "bary" from killing prey the size of a fully-grown Iguanodon in spite of the former's huge thumbclaws. Incidentally, Iguanodon too had oversized thumbnails, but they were almost-straight and not curved like the carnivore's.

Since the 1980s, Baryonyx has been one of the most frequently-portrayed large theropods in popular dino-books. On the other hand, it has long been ignored in Fictionland and even most TV documentaries. It should have appeared in Walking with Dinosaurs as the predator of Iguanodon, but was finally substituted by the misplaced giant dromaeosaur Utahraptor in this role. It came into the spotlight in 2009 thanks to the Ice Age: Dawn of the Dinosaurs film. Here an oversized Baryonyx called Rudy is the pseudo-rex Big Bad who is even bigger than the JP III spinosaur or the real-life one, and an excellent example of the Savage Spinosaurs and Spinosaurus Versus T. rex tropes.

The Baryonyx is unnamed however (some dino-fans wrongly thought he was a Suchomimus), and quite inaccurate, with a head shaped like a literal crocodile's and hands lacking the distinctive thumbclaws. Rudy is an albino; unlike chameleon-like carnotaurs, albino dinosaurs were possible in Real Life but probably very rare, and the predatory ones shouldn't have been good hunters because of their non-mimetic color and eyesight problems. In 2018, the Jurassic Park franchise added the Baryonyx as one of the animals in its 5th movie, and in 2021 the dinosaur had a major role in the animated TV series Jurassic World: Camp Cretaceous, in which a trio of Baryonyxes feature in the second season of the show.

1. Entry Time: 2009
2. Trope Maker: Ice Age: Dawn of the Dinosaurs

Giant Predator of the South: Giganotosaurus **

Carolini's Giant Southern Lizard

Giganotosaurus carolinii (NOT "Gigantosaurus"; that name was used for an invalid sauropod) lived in Late Cretaceous South America 100-95 million years ago. A close relative of Allosaurus, it had a bigger head (6ft/1.8m long, even longer than a Tyrannosaur’s) and a stockier build: it looks rather like a cross between an allosaur and a tyrannosaur — incidentally, making the classic hybrid allo/tyranno so often seen in classic films (Fantasia, One Million B.C....) a sort of Truth in Television.

Discovered in 1993 and officially described two years later, Giganotosaurus was celebrated as "the biggest predatory dinosaur ever," surpassing Tyrannosaurus and Spinosaurus: the largest specimen known of the former at the time (the famous Sue) was discovered a few years before — now the record is contended by the specimen "Scotty" described in 2019. The same year it was described, James Gurney (who got permission to feature it from Giganotosaurus's co-describer Rodolfo Coria) included it in Dinotopia: The World Beneath in a memorable Summon Bigger Fish scene against a T. rex. The "giga" remained the record-holder until new Spinosaurus fossils were discovered in the 2000s, and the re-examination of the descriptions of older finds reminded us that the "spino" was even larger, something already postulated but ignored for 80 years.

At the same time, re-examination of Giganotosaurus remains show an animal not much larger that Tyrannosaurus; the only advantage in length is due to a longer snout, and were the two animals placed side-by-side, they'd appear to be the same size. Its close relative Carcharodontosaurus (known since the first half of the 20th century in the form of teeth and some sparse bones, but rediscovered in 1995), got the same treatment of Giganotosaurus in the 1990s, but ultimately lost the struggle against it for widespread recognition; and both theropods ended up overshadowed in popular culture by Spinosaurus.

Giganotosaurus remains one of the most powerful meat-eaters that ever lived, and has started to gain popularity. The fact that it could have possibly hunted some of the largest sauropods — aka those Brontosaurus relatives belonging to the titanosaur subgroup, see the Sauropods section — means that it may become very popular in the future. If that doesn't sound cool enough, then consider that to do so, it would have had to be a pack hunter. Chased by Dinosaurs did a special on just how badass such a hunt would be, even though in the show the long-necked dinosaur that became prey was a juvenile. Though there isn't any evidence for pack behavior in Giganotosaurus, there might be for its closest relative, the nigh-identical Mapusaurus (initially considered), which was the same length but had a slightly slenderer frame. Carcharodontosaurus and Mapusaurus are both represented in Planet Dinosaur, a BBC doc made in 2011 considered the "heir" of the 1999 Walking With Dinosaurs, but both fail to hunt successfully the giant sauropods of their habitat (Paralititan and Argentinosaurus respectively). Due to their reputations as the biggest meat-eater and biggest plant-eater among dinosaurs and the fact they both lived in South America during the Late Cretaceous, Giganotosaurus itself is often portrayed preying on Argentinosaurus, but this is either Anachronism Stew or Misplaced Wildlife, as the two were found in separate formations, with the former being slightly older than the latter (approx. 100 mya vs approx. 95 mya). There were giant sauropods living alongside the "giga", like Andesaurus, but Argentinosaurus would have been menaced by Mapusaurus.

Giganotosaurus has a big star role in 2022’s Jurassic World: Dominion, in which it is the main dinosaur antagonist. In the prologue set 65 million years ago, it duels and kills a Tyrannosaurus rex (Anachronism Stew and Misplaced Wildlife at their finest) who will later be cloned into “Rexy”, and has also been resurrected for the modern day itself.

1. Entry Time: 1995
2. Trope Maker: Dinotopia: The World Beneath

Missed Moment of Glory!: Carcharodontosaurus *

In 1995, an unexpected find deeply shook the paleontological world and the dino-fandom. The obscure-at-the-time Carcharodontosaurus saharicus ("Great white shark lizard of the Sahara") was revealed not to be an indeterminate theropod as was once believed - it was originally considered a megalosaur, but others thought it was a ceratosaur, an allosaur, a tyrannosaur or even a relative of ornithomimosaurs or a completely unique theropod that returned to the seas! It was a much more badass animal, whose sesquipedalian genus name — one of the longest in the whole dinosaur world, with 19 letters — has turned out to be stunningly apt. A predatory dinosaur even bigger than T. rex! Note that Carcharodon is also the genus name of the modern great white shark, and was once attributed even to the huge extinct shark megalodon.

Obviously, popular media ballyhooed the discovery a lot, ignoring the fact that the original material already indicated a giant animal. In any case, the glory of Carcharodontosaurus didn’t last a long time; merely one year later, it was surpassed by the just-discovered, almost-identical, only a bit bigger, Giganotosaurus carolinii(Which was an extremely close relative). Our “shark toothed dino” was a quite unlucky dinosaur, really.

However, in the 2000s, Spinosaurus has in a sense done justice to the carcharodontosaur, taking in turn the popularity of Giganotosaurus out thanks to Jurassic Park III. The awesome thing is, in Real Life Carcharodontosaurus and Spinosaurus living together in Cretaceous Africa where today is Sahara, maybe contended the “top-predator” niche with each other. While Carcharodontosaurus was better-weaponed with huge jaws, Spinosaurus was more enormous-bodied and could have been even twice its weight. They were often considered the “tiger” and the “grizzly bear” of their time respectively, and it was often supposed that Spinosaurus sometimes chased away Carcharodontosaurus from their kills like modern bears do with big cats when they live side-by-side — at least, before recent research controversially suggesting the spinosaur not to be a land-dweller but a semi-aquatic animal with a finned tail. Maybe they never fought in real life, due to the very different habitats (shallow seas and dryland respectively).

1. Entry Time: 2011
2. Trope Maker: Planet Dinosaur (documentary)

Hunting in Packs?: Mapusaurus *

As a Consolation Prize, Carcharodontosaurus has been chosen as the official namesake of its own family, a recently-identified group of gigantic Cretaceous allosauroids which were also among the most evolved carnosaurs: carcharodontosaurids. Other than Carcharodontosaurus, Giganotosaurus & Acrocanthosaurus, they include animals discovered in the 2000s: among these, Mapusaurus Found only in 2006 in Argentina, it was maybe the closest relative of Giganotosaurus, and may have been its descendant in Real Life. Almost as big as “Giga”, Mapusaurus was almost identical to it and to Carcharodontosaurus, with huge skull filled with crests and protuberances, and the usual powerful three-fingered hands of all allosauroids. However, the most interesting thing is that its fossils seem to show proof of group behavior. Even though this doesn’t automatically indicate “pack hunting” (they may have just been an unorganized mob temporarily banding together to kill a selected target), many have now fun to imagine awesome scenarios, with pack of Mapusaurus killing together the immense sauropods of the time like Argentinosaurus. This behaviour was also speculatively attributed to Giganotosaurus in the “Land of Giants” episode of the WWD special.

Among other carcharodontosaurids, Tyrannotitan is worthy of note because of its name “tyrant titan”, one of the most "rex"-like of all theropods, even though its owner, being an allosauroid, was not so closely related to T. rex. An early Cretaceous animal, it was more primitive than the examples above, but still with a fully carcharodontosaurian skull. Even more primitive were Eocarcharia ("dawn carcharodontosaurid"), Sauroniops ("eye of Sauron"), Veterupristisaurus ("old shark reptile"), all from Africa, and Meraxes (named after the dragon of Queen Rhaenys Targaryen from A Song of Ice and Fire), a South-American kind described in 2022, with reduced forelimbs convergently with tyrannosaurids. The smallish European Concavenator too, despite its unusual feature (the "sail" or "hump" on its pelvis), belongs to the carcharo's family.

According to many scientists, the biggest carcharodontosaurids evolved specifically to tack the most challenging of all prey animals, the giant sauropods that weighed several dozen tons apiece. Their method of attack was arguably Death of a Thousand Cuts, using their wide-opening jaws typical of allosauroids and shark-like teeth to tear off huge chunks of flesh off the living sauropod until it was literally Eaten Alive and died of shock and blood loss. Other large theropods, such as T. rex, were perhaps unable to kill adult sauropods, as their stronger bite worked against them in opening the mouth wide enough.

1. Entry Time: 2011
2. Trope Maker: Planet Dinosaur (documentary)

Meat-loving Sprinting Bull: Carnotaurus **

Sastre's Flesh Bull

Another South American theropod like Giganotosaurus, Carnotaurus sastrei (yes, "-taurus", not "-saurus")^note  "Carnosaurs" were a group of theropods that include Allosaurus, and the aforementioned Giganotosaurus and Carcharodontosaurus. lived in the Late Cretaceous in a younger age, 70 million years ago. Discovered in Argentina in 1985 by Jose Bonaparte (possibly Latin America's greatest paleontologist), it is known from a single specimen, but this was one of these things every paleontologist wishes to find: one of very few big theropods so far found with skin impressions. As these prints are from the whole right side of its body, Carnotaurus is one of the only large dinosaurs whose external look is known with a reasonable degree of certainty, together with the so-called "hadrosaur mummies" of Edmontosaurus. We don't know what was the coloration of the living Carnotaurus, however.

Our carnotaur has also revealed to be one of the strangest-looking dinosaurs known. Forelimbs even tinier than those of T. rex, sort of useless stubs with no true fingers (though three clawed fingers appear in many portrayals, and sometimes even a small Iguanodon-like thumbclaw for each hand) that contrast vividly with the long legs apt for high-speed runs ^note in fact studies of Carnotaurus's femur and tail show that it would have been one of the fastest large theropods, with running adaptions better than a human. Unusually shortened head (some compare it to a bulldog's). Above all, a couple of unique bull-like horns above the eyes which no other known theropod had, not even its closest relatives: Carnotaurus means "meat-(eating) bull". Finally, its skin was covered by rows of horny tubercles. The horns and the skin make Carnotaurus a quite dragon-looking dinosaur. Ironically, with its slender body, tiny forearms, and fragile lower jaws, it's hard to imagine how it could kill large prey in Real Life, especially if you think it doesn't come close to rivalling Tyrannosaurus or Giganotosaurus in size (it was only about 22ft/7m or so in length, while a big rex would be about 43ft/13m). A clue may come from the fact it could have been the fastest non-bird dinosaur ever discovered, perhaps being able to run at 75 miles per hour. It has been suggested it ran into prey at full speed with jaws open, using its head as a sledgehammer.

Carnotaurus has become somewhat popular since the Nineties thanks to its striking look. Its most remembered appearance is in the 2000 Disney’s Dinosaur, where it's shown as an oversized, pseudo-rex villain. Here, the biggest carnotaur appears even larger than a spinosaur, able to lift an Iguanodon with its jaws, and fling it to death against a rock. In Real Life the 1-ton Carnotaurus was much smaller and weaker than the 5-ton Iguanodon, and lived several million years after the latter. Before that, it also showed up in Michael Crichton's second Jurassic Park book, where its size was portrayed more accurately, but to up the threat level, it was given (quite implausible) chameleon-style stealth abilities. Note that neither modern birds nor crocodilians can change their colors rapidly like chameleons do. Finally, it made a cameo in 2018's Jurassic World: Fallen Kingdom and appeared as a major villain in the first season of 2020's animated spinoff Jurassic World: Camp Cretaceous.

Carnotaurus may be the responsible for the decline of the classic carnivore Ceratosaurus in media during The New '10s, as both dinosaurs had a similarly horned/tubercled look and the two dinos might be confused with each other, even though their look was rather different. But also note a bit of resemblance both in shape and in name between the carnotaur and a mythical critter, the Minotaur. This association may have at least subconsciously led to it becoming a go-to bad guy dinosaur.

1. Entry Time: 1995
2. Trope Maker: The Lost World (1995) (novel)

Horned Rex or Underdog?: Ceratosaurus **

Ceratosaurus nasicornis ("horned-nosed horned lizard": "nasicornis" is Latin for "horned-nose", while "cerato-" is Greek for "horn") lived in the same places as Allosaurus in the Late Jurassic, 153-148 mya. Usually 17-23ft/5-7m long, it was usually smaller than the other Stock Theropods above, but still a powerful animal.

Ceratosaurus looked more like an undersized allosaur than the others, having the same eye-bosses and long forelimbs of it. Its name underlines its more distinctive anatomical feature: a laterally flat crest on its nose, classically described as a "nasal horn". ^note As you can tell now, many big theropods developed some ornamentation on their head: probably Allosaurus, Ceratosaurus, Carnotaurus and so on used their horns and bony-knobs as simple display tools and not as weapons against their prey, but others think they could have used them in fights against each other, ex. for mating or territorial purposes. It was also the only known theropod to have a true armor in the form of bony plates along the middle of its neck, back, and tail. While the "horn" is the hallmark in every Ceratosaurus portrayal (don't be surprised to see it shaped like a rhino's), the armor can be left out altogether, or alternatively, modified to make the animal similar to a dragon.

Despite its appearance, Ceratosaurus was actually more archaic than Allosaurus. Allosaurus belongs to the Tetanuran branch of theropods, while Ceratosaurus is the namesake of its own branch, Ceratosaurians. The latter can be told apart from tetanurans by the primitive shape of their pelvis, more flexible tails, and a remnant fourth finger on each hand (tetanuran theropods never have more than three fingers). Most of the other theropods discussed in Stock Dinosaurs are tetanurans, except fellow ceratosaurians Carnotaurus & Majungasaurus and the two even more primitive most known coelophysoids, Dilophosaurus and Coelophysis.

Ceratosaurus was first found during the Bone Wars like Allosaurus, but is much rarer in the fossil record than the latter: many paleontologists suspect it was more solitary than allosaurs. In paleo-art and documentaries, Ceratosaurus can be shown either as a scavenger / an underdog predator, or as a pack-hunter of big game. While Allosaurus is seen as the "lion" of its time, Ceratosaurus might be considered the "hyena"; with its smaller size, longer teeth and stronger jaws, the comparison works. Since Real Life spotted hyenas are not lions' underdogs as seen in The Lion King, with both co-dominating the top-predator niche, it's possible that ceratosaurs and allosaurs had a similar relationship; but also remember that comparing dinosaurs with modern mammals on 1-to-1 basis is something to be cautious about in paleontology.

The horn on its nose and the armor make Ceratosaurus the most "dragon-looking" of the theropods known at the start of the 20th century (remember that all the carnivores in this folder were found later than it except for Megalosaurus). It's not a big surprise that it appeared in so many classic dino films, from simple cameos like Fantasia (where is presented as an opportunistic scavenger of dying herbivores) up to being the main dino actor, like the Ray Harryhausen film/documentary Animal World, in which two ceratosaurs get into a fight and fall off a cliff..

Ceratosaurus might be the first non-avian dinosaur ever to appear in a work set in modern times, with the 1908 short story The Monster of Partridge Creek focusing on an overgrown, shaggy-coated specimen roaming around Canada's Yukon territory. This makes it also the first dinosaur to be fictionally portrayed with feathers. It also holds the record of being the first dinosaur ever shown in non-animated cinema — the 1914 film Brute Force pitted cavemen against dinosaurs and helped popularize the Dinosaurs Are Dragons trope, making the Ceratosaurus very important within the relatively brief history of popular depictions of dinosaurs, to the point where even a pure fantasy movie like Hercules (1958) makes its dragon look distinctly ceratosaurian. In later fiction Ceratosaurus received the same treatment as Allosaurus, acting as a T. rex substitute for the Big Bad part. With its distinctive horned/armored look, Ceratosaurus is less likely than Allosaurus to be confused with Tyrannosaurus; on the other hand, its size is often exaggerated to make it more of a "horned tyrannosaur", like in another Harryhausen's movie, One Million Years B.C., where it's seen fighting a Triceratops but is gored to death by it.

Ceratosaurus is quite rare in films today, however: The only major example is a short cameo in Jurassic Park III, in which it's not even named, but is at least correctly sized. Allosaurus entered the Jurassic Park franchise only in 2018, in the Jurassic World sequel Fallen Kingdom with a brief cameo as well. Even modern documentaries rarely represent the ceratosaur — the Walking with Dinosaurs series didn't show it at all for some reason. The Ceratosaurus decline is probably due to the occurrence of the other, newly-discovered big predatory theropods described here: Carnotaurus in particular, being similar yet even more badass looking for some thanks to its two bull-like horns.

1. Entry Time: 1908
2. Trope Maker: The Monster of Partridge Creek (short story)

Smaller and Swifter: Albertosaurus, Gorgosaurus & Nanuqsaurus *

It's Albertosaurus, and not Tyrannosaurus rex, the most abundant tyrannosaurid in fossil record, and it's also the second big-sized theropod by wealth of fossil material, just after the unbeatable Allosaurus. And yet, Albertosaurus has not gained much attention in films and comics as Tyrannosaurus — tyrannosaurids are so similar to each other that if one appears in cinema, people will always call it T. rex. To compensate, Albertosaurus is a very common sight in many paleo-books, just as common as several other stock theropods. Its full name, Albertosaurus sarcophagus, means "meat-eating lizard of Alberta".

Like Tyrannosaurus, Albertosaurus is portrayed as the superpredator of its time, North America 71-68 million years ago, disappearing at almost exactly the same time T. rex showed up (which has in turn led some paleontologists to theorize that T. rex outcompeted it). The menu of an Albertosaurus was probably not monotonous; several kinds of herbivores roamed North American plains at the time, from ceratopsians to hadrosaurs, from the armored ankylosaurs to small swift parksosaurs, pachycephalosaurs and ornithomimids. Even though tyrannosaurids are classically shown battling some powerful prey, they more probably hunted young individuals more often, to avoid the risk of fatal injuries or consequent infections.

Compared with the legendary Tyrannosaurus, Albertosaurus was like a leopard compared with a lion or a tiger; smaller (30ft/9m long against the 40 ft of T. rex), it was also slenderer, with longer, thinner jaws, smaller teeth, and more agile legs apt to higher top speeds than Tyrannosaurus. It had also small but distinctive "hornlets" above its eyes; one could thus say it was a tyrannosaurid version of Allosaurus. Even the herbivores which shared their world were matched with tyrannosaurids; those which lived alongside T. rex were bigger, slower and more heavily armored than those living with Albertosaurus.

Albertosaurus was also the first dinosaur ever discovered in Canada, at the end of the 19th century, but was named after the Canadian province of Alberta only in 1905 (incidentally, the same year as Tyrannosaurus, and the same year its namesake province was founded), Alberta being where most of the abundant Canadian dinos have been discovered. Albertosaurus has also contributed indirectly to the popular image of tyrannosaurs. The forelimbs of Albertosaurus have been known since its very first find, while those of T. rex were first discovered only in the 1990s; for almost a century the well-known two-fingered hands of "rex" have been modeled upon those of Albertosaurus, debunking at the time the old pop-cultural Hand Wave about portraying three-fingered tyrannosaurs. ^note Beware, we’re talking about functional fingers, not the third vestigial digit present in T. rex

Discovered in 1914, Gorgosaurus libratus ("balanced monster lizard") is another North American tyrannosaurid which was long considered a distinct genus compared to Albertosaurus. Then, in the 1970s, Canadian paleontologist Dale Russell found the two animals so similar they had to been put under a single name: since the first created name always has priority, so was Albertosaurus. Only in recent years, scientists changed idea again separating "Gorgosaurus" from "Albertosaurus" — the whole process is always quite arbitrary in paleontology, never forget this. There has also been a curious sequence in pop-portraits: Gorgosaurus has long been the most depicted non-"rex" tyrannosaur in classic paleo-art and old books, also thanks to a famous painting made by Czech paleoartist Zdenek Burian in the 1910s which started the trope; then, its long-lasting synonimization with Albertosaurus harmed its relevance, and Albertosaurus was usually regarded as the new prototypical “small” North American tyrannosaur until 2013, when Gorgosaurus made its way into cinema by playing the main antagonist of the 2013 Walking with Dinosaurs movie.

2014 saw the discovery of a truly unusual North American tyrannosaurid, this one from the same time period as Abertosaurus and about the same size. However, there's no chance that the two could have met, because Nanuqsaurus ("polar-bear lizard") lived above the Arctic Circle, in Alaska — hence the name. It was initially believed to be a late-surviving species of Gorgosaurus, but was later reclassified as its own genus. This means that the tyrannosaur villains in the 2013 Walking With Dinosaurs movie, though labeled as Gorgosaurus, could actually be Nanuqsaurus. A trio of unambiguous Nanuqsaurus were featured prominently in 2022's Prehistoric Planet, where they hunt a herd of Pachyrhinosaurus in a sequence very much modelled on wolves hunting musk oxen. The second season also features a single Nanuqsaurus hunting Ornithomimus, and sharing the kill with her babies.

1. Entry Time: 2000s (Albertosaurus); 2011 (Gorgosaurus); 2014 (Nanuqsaurus)
2. Trope Maker: Jurassic Park: Trespasser (Albertosaurus); the March of the Dinosaurs film (Gorgosaurus); Documentary Media (Nanuqsaurus)

Tyrannosaurus or not?: Tarbosaurus & Daspletosaurus *

Tarbosaurus bataar means "Alarming hero lizard". If you want to describe it, don’t worry, it’s a simple thing: just say it was the Asian twin of Tyrannosaurus rex and you’ve given the idea. To be more accurate, Tarbosaurus was slightly smaller than Tyrannosaurus, with a narrower snout and a slightly lighter trunk, but shared with the "rex" the same familiar body-shape. Its forelimbs were identical to T. rex but a bit smaller, sometimes cited as “the smallest arms in the dinosaur world” - even though the “horned” theropod Carnotaurus had even more reduced arms, as did some flightless birds like the recently-extinct Moas (see below) and others.

Tarbosaurus was the "king" of the predators in its habitat, Late Cretaceous Asia, just like T. rex in North America. These two dinosaurs are so similar, that some scientists suggested in the past that Tarbosaurus is another species of the genus Tyrannosaurus (Tyrannosaurus bataar), but the newest studies seem to disagree. Maybe some smaller North American tyrannosaurs were closer to T. rex than Tarbosaurus. The tarbosaur may be closest to Zhuchengtyrannus, an Asian tyrannosaur named in 2011, while "Jenghizkhan" (from the Mongolian Gengis Khan), described in 1995, is today just an invalid synonym of Tarbosaurus.

Tarbosaurus was very similar to T. rex but wasn't identical, and there were differences that inexperienced writers and artists often miss. Tarbosaurus had a narrower, less powerful skull, a unique locking mechanism, less-binocular vision, and smaller but sharper and more serrated teeth than its American cousin. These suggest it was not as adapted to feed on armored prey like ceratopsians and ankylosaurs, and instead favored preying upon large hadrosaurs, sauropods and other theropods such as Therizinosaurus and Deinocheirus. This is supported by isotopic analyses of tarbosaur teeth and bite marks found on skeletons of Deinocheirus, but we also know tarbo and rex both enjoyed the taste of hadrosaurs. Another interesting detail is that tarbosaur fossils are more commonly found together than T. rex fossis, suggesting they may have been pack hunters.

Tarbosaurus has been first discovered in 1955 in Mongolia, more precisely in the Gobi Desert. Mongolia, a sparsely populated Asian country bordered by Russia and China, has always had a major role in the brief history of paleontology: despite being much smaller than China, Canada or the USA, it has given us the same number of fossils of each of them, almost all from Late Cretaceous. Among them, most of the classic Asian dinosaurs: from the famed Protoceratops/Velociraptor battle to the first Mesozoic dinosaur eggs ever discovered, from oviraptorids to the huge Deinocheirus, from the duckbilled Saurolophus to the ostrich-like Gallimimus to the "parrot dinosaur" Psittacosaurus, ankylosaurs like Pinacosaurus, titanosaur sauropods, small pachycephalosaurs, the birdlike Avimimus, Segnosaurus, Saurornithoides, Mononykus, and the scythe-claws of Therizinosaurus.

Interestingly, the succession of geological periods (Cretaceous-Jurassic-Triassic) of the Mesozoic era, have also a distribution in latitude which is amazingly specular in Asia and in North America. In both continents, the Cretaceous terrains are those in the northern part of the range (Alberta, Canada/Montana, USA, and Mongolia/Inner Mongolia/Northern China); the Triassic terrains are the most southern (Arizona/New Mexico, USA, and the province of Yunnan, southern China); while the Jurassic ones were in the middle (Utah/Colorado/Wyoming, and the province of Szechuan, central China). Also note that most North American dinosaurs have been discovered in western USA and western Canada (not in the coastal region however, but only in the Rocky Mountains and the Great Plains); while the Asian dinosaurs are concentrated in only two countries, Mongolia and China, both in the Far East (Japanese and Korean dinosaurs are extremely rare).

Despite (or perhaps because of) its similarity to T. rex, Tarbosaurus has rarely appeared in fiction. Its first notable appearance was in the original novel Carnosaur by John Brosnan where it had the spotlight as the main threat of the book and was even pointed out by name to differentiate from its more famous cousin, and it was also in Chased by Dinosaurs. More recently, Tarbosaurus has become the star of a South Korean animated film titled Speckles: The Tarbosaurus, which had a sequel released in 2017. Tarbosaurus also appears in Prehistoric Planet, where its behaviour and skin patterns are subtly modeled on those of tigers, emphasizing its role as the top predator in its Asian environment.

In the 1970s, a third North American tyrannosaur was recognized as distinct from Tyrannosaurus and Gorgosaurus/Albertosaurus: Daspletosaurus torosus (the genus name meaning "frightful lizard"). The same size of the latest two and living in the same epoch as the "gorgo", Daspletosaurus was actually more similar to T. rex than to Albertosaurus/Gorgosaurus in anatomy, and some thought it was the rex's direct ancestor, or even a small species of Tyrannosaurus, Tyrannosaurus torosus - these ideas are now outdated. It is now believed that Daspletosaurus was quite distantly related from T. rex, and only looked similar due to convergent evolution, instead representing a uniquely North American lineage of robustly-built tyrannosaurids as opposed to the Asian-descended T. rex. Anyway, many scientists think the more agile Gorgosaurus specialized on relatively easier prey such as hadrosaurs, young ceratopsians, and ornithomimids, while the more powerfully-built Daspletosaurus hunted “armored” herbivores like adult ceratopsians and ankylosaurs. The daspletosaur appears as one of the four protagonist dinosaurs of the docu-series Dinosaur Planet: a youngster named "Little Das" — quite possibly named after the allosaur "Big Al" of Walking with Dinosaurs fame.

1. Entry Time: 1984 (Tarbosaurus); 2003 (Daspletosaurus)
2. Trope Maker: Carnosaur (Tarbosaurus); Dinosaur Planet (Daspletosaurus)

Sail-backed Allosaurs: Acrocanthosaurus & Yangchuanosaurus *

Spinosaurus was not the only theropod with a ridge on its back made by elongated neural spines: there were others as well. Acrocanthosaurus atokensis is the most well-known among “these others”. However, its “sail” was very different; only one foot tall, it extended from the neck to the tail-tip, while that of Spinosaurus was far higher but limited to the back. Actually, the sail of Acrocanthosaurus could have been buried in flesh in the living animal, making it looking even bigger when seen from the side, just like what could have been for Spinosaurus.

Acrocanthosaurus ("tall-spined lizard") was not a spinosaur relative at all, even though it and other sailbacks like Altispinax and Metriacanthosaurus were classified as such in the past just because of their sails: actually was an allosauroid, traditionally classified as being between Giganotosaurus and Allosaurus phylogenetically. The most recent analyses support it was a true carcharodontosaurid, making it closer to Giganotosaurus. Acrocanthosaurus lived in Early Cretaceous North America about 113-110 mya, rather between Allosaurus and Tyrannosaurus in the time scale. Apart from the “sail”, it was similar to a robust Allosaurus in shape, and with its 12 m long body was as big as Tyrannosaurus rex, albeit of lighter build.

One could even say Acrocanthosaurus combined the best powers of the four most popular giant theropods. The size of "rex" (almost), the overall robustness of “Giga”, the powerful three-clawed forelimbs of “Allo”, and a crested back like “Spino”. Yet, have you sometimes seen this dinosaur outside dino-books (apart from the pseudo-docu Monsters Resurrected)? Things get even worse if you consider Acrocanthosaurus has been known since the 1940s from rather complete remains, was the top-predator of Early Cretaceous North America, and shared the same habitat with another famous (but much smaller) “killer dinosaur" Deinonychus. However, Bob Bakker’s scientific novel Raptor Red does justice to Acrocanthosaurus, portraying it as the great predator of the world in which Utahraptor are the main characters (although Utahraptor actually lived about 20-25 million years earlier than "Acro" did).

Many allosauroids have been found in Asia, notably in China. This is evident if you read their names: the most classic example is Yangchuanosaurus (Yongchuan is a district of the city of Chongqing in the Chinese province of Sichuan). This one is often considered the “Chinese Allosaurus”: only a bit smaller and with a shorter, taller skull with the usual Allosaurus-like crests on the snout; robust, three-fingered forelimbs, and a small ridge on its back, but shorter than Acrocanthosaurus. Yangchuanosaurus was probably the top-predator of Late Jurassic Asia (155-145 million years ago), and lived alongside two of the most famed Chinese Jurassic dinosaurs, the sauropod Mamenchisaurus and the stegosaur Tuojiangosaurus. In dinosaur books and documentaries, it is typically shown as the main predator of the Jurassic Asian herbivorous dinosaurs — sometimes confused with Sinraptor, which was actually another kind of allosauroid of the same fauna, very similar to Yangchuanosaurus but smaller.

1. Entry Time: 1995 (Acrocanthosaurus); undetermined for Yangchuanosaurus
2. Trope Maker: Raptor Red (Acrocanthosaurus); its status of "the Asian Allosaur" (Yangchuanosaurus)

Recently Popular: Torvosaurus & Majungasaurus *

The largest megalosaurid, as well as the one most closely related to Megalosaurus itself, has been found in North America and Portugal: Torvosaurus (“savage lizard"). Its most known species is Torvosaurus tanneri. Probable synonyms are Edmarka rex (not that rex), and "Brontoraptor" (the latter name is not officialized, and is therefore not italicized). 10 m long or more, the same size as Allosaurus fragilis but more powerfully-built, Torvosaurus shared the same habitat with Allosaurus and maybe sometimes took some prey out of it. However, the fossil record seems to show that the giant megalosaurid didn’t make true rival for allosaurs: it was much, much rarer than the latter, and this leads to speculation that allosauroids were more efficient hunters, and finally replaced most megalosauroids. In recent years the Torvosaurus is often portrayed as a Goliath figure to Allosaurus 's David. However, the spinosaurids are currently believed to be descended from the megalosaurids, so Torvosaurus and its kin don't need to feel ashamed.

Many Carnotaurus relatives showed some kind of ornamentation on their skull, though none had the "bovine" horn of a Carnotaurus. Majungasaurus crenatissimus is an excellent example of this. One of the few dinosaurs found in Madagascar (named after the Mahajanga province, which hosts the site it was dug out), it was not bigger than Carnotaurus and shared a similar overall look, but with shorter legs and one single horn atop of its head. This dinosaur has had a curious Science Marches On story: initially only its blunt horn was known, and because of its shape was thought to be the domehead of a tiny pachycephalosaur called “Majungatholus” until better remains were found in the '90s. Then, this name was applied to the carnivore until 2007 when it turned out some fragmentary remains named Majungasaurus several decades earlier were identical to "Majungatholus"; for example, in the wrestling-style pseudo-documentary Jurassic Fight Club this theropod appears named “Majungatholus”. Here, two adults are shown cannibalizing a young of their own species; this was based upon some marks of teeth on the bones of young Majungasaurus specimens, whose shape match the teeth of adult Majungasaurus. Another dinosaur that once was famous for being described as cannibalistic is Coelophysis, but see in another section for this one.

1. Entry Time: 2011 (Torvosaurus); 2008 (Majungasaurus)
2. Trope Maker: Dinosaur Revolution (Torvosaurus); Jurassic Fight Club (Majungasaurus)

The First Named Non-bird Dinosaur: Megalosaurus **

Buckland's Great Lizard

We've already mentioned Megalosaurus more than once. Why? Well, both because it was the first giant theropod known to science, and because it shows neatly how Science Marches On is normal stuff in dino-science.

Its first remains, the extremity of a leg-bone found in 1676 in England near Oxford, was mistaken by Robert Plot for the remains of an ancient giant man (others named this remain Scrotum humanum because of its shape, and thank goodness that name didn't stick), but this fossil has since been lost. Later, a half lower jaw with a single large tooth left was found in 1824 in Southern England; its discoverer, reverend and geologist William Buckland, described it as belonging to a "big lizard" (the meaning of its name, which started the tradition of "saurus" in dinosaur names). Buckland didn’t realize he had named the very first non-avian dinosaur.

The scientific and popular view of what a megalosaur was has gone through several drastic changes. The first attempt at reconstruction, the life-size sculpture in Crystal Palace Park constructed in the 1850s, made the Megalosaurus a dragon-like animal walking on all fours. Next to the Megalosaurus was an Iguanodon sculpture (also quadrupedal), and for several decades, this was the stock image of the world of dinosaurs: one herbivorous dragon facing a carnivorous dragon in combat◊. From this time is Charles Dickens' novel Bleak House (1853) where Megalosaurus is mentioned, described as an "elephantine lizard". This is the very first time a dinosaur is referenced in popular culture (the ichthyosaur and the plesiosaur of Jules Verne's Journey to the Center of the Earth are NOT dinosaurs).

New genera of large carnivores were described during the Bone Wars, such as Allosaurus and Ceratosaurus, whose more complete remains showed clearly bipedal animals. Since then, Megalosaurus has also been reconstructed as bipedal. Even with their correct shapes, the "Megalosaurus vs Iguanodon" battle has remained a classic in non-fictional portrayals (a bit like "Tyrannosaurus vs Triceratops"), even though in Real Life the megalosaur was a middle Jurassic animal (166 mya), while the iguanodont lived 40 million years later in the Early Cretaceous.

The tendency to classify theropod fossils of every kind as Megalosaurus started soon after its first description. After the Bone Wars, Megalosaurus remained a "Wastebasket taxon" to which all finds that were too incomplete or too ambiguous were assigned. Megalosauruses cropped up everywhere from North America to Africa to Australia, and from Early Jurassic to Late Cretaceous. Later, scientists progressively sorted out outsiders into more than 20 genera (Carcharodontosaurus, Dilophosaurus, Eustreptospondylus, Altispinax, Metriacanthosaurus, Majungasaurus, and Proceratosaurus among them). This cleanup has yet to be finished. See also Prehistoric Life - Large Theropods.

The only-valid Megalosaurus species is named Megalosaurus bucklandi from its discoverer Buckland. It's a fairly generic theropod some 30ft/9m in length, similar to an elongated allosaur but slightly smaller and more primitive, with little-visible brow-horns but robust jaws and teeth, and three powerful claws on each hand. Some old popular portraits represent it as very massive and powerful, hunting alone even giant sauropods like Cetiosaurus.

Even though its historical relevance makes it a common sight in classic and modern dino-books (especially common are the photos of its original jaw), the "big lizard" didn't go a long way in popular works after the two important mentions in early literature (Bleak House and The Lost World). In the 20th century it heavily suffered the competition with Tyrannosaurus and Allosaurus — and the resolution of the "wastebasket" issue made the case against it even worse according to some, while according to others this cleanup had little influence to the "megalo"'s decline which had already started before the reclassification of the other alleged species. Apart from some occasional documentary like Walter Cronkite 's "Dinosaur!", you have little chance of seeing any megalosaur either in cinema or in TV media — just as an example, Walking with Dinosaurs chose to portray the contemporary close-relative Eustreptospondylus (once called Megalosaurus oxoniensis) in the Jurassic Europe episode, being scientifically better-known though smaller/more slender than M. bucklandi. But worthy of note is the TV show Dinosaurs which has one "megalosaur" in the form of Earl Sinclair, which is the main dinosaur-character of the series: he's an anthropomorphic dinosaur who doesn't look particularly like any kind of Real Life dino, but is portrayed as robust and massive, looking not unlike the Crystal Palace Megalosaurus.

1. Entry Time: 1854
2. Trope Maker: Crystal Palace Dinosaurs

Double-crested Forerunner: Dilophosaurus **

John Wetherill's Two-Crested Lizard

Dilophosaurus wetherilli lived 197 million years ago in Early Jurassic North America. It was one of the first theropods to have exceeded human size: 20 ft / 6 m long, like a big Nile Croc/American Gator, but with a slender body frame compared with the animals above, and weighing 500 kg (like a medium horse), while the more evolved Ceratosaurus was about the same length but double the weight, being more robustly-bodied. While its size could make you think the "dilopho" was more closely related to some of the large theropods of this folder, it was actually closer to the dog-sized Coelophysis: that is, it was an overgrown coelophysoid. Among the big theropods here, the closest to Dilophosaurus were the Ceratosaurians, like Ceratosaurus and Carnotaurus.

Its most easily recognizable trait in Real Life is the two parallel bony crests on its skull, perhaps occurring only in males, probably used for display; they were present, though less-developed, in other coelophysoids like the neighboring 20 ft / 3 m long "Coelophysis" kayentakatae^note a currently unnamed dinosaur tentatively assigned to Coelophysis but may actually be representative of Megapnosaurus. The dilophosaurian crests were thinner and more delicate than the robust horns and cranial prominences of Carnotaurus and Ceratosaurus, and are classically thought easily breakable crests in a fight; so, the dilophosaur was traditionally thought a no-badass dinosaur because of this. Its head was long and narrow, and the upper jaw had a deep indentation on each side near the tip of the snout, apparently making the whole structure even weaker. However, popular dilophosaur portraits usually don't show this pair of "pits", which were also present (but much smaller) in Coelophysis and other relatives. Scientists have usually said the dilophosaur was a mere scavenger or a small prey hunter, even though some had initially described it as the "first giant killer dinosaur". It was indeed one of the biggest terrestrial carnivores of its time; however, really powerful meat-eating dinosaurs only started to appear in the Middle Jurassic, like Megalosaurus above. ^note Note that Early Jurassic dinosaurs were more similar to Triassic dinosaurs than to the bigger/more evolved dinosaurs from the remaining Jurassic period. Some dino-books even mix Triassic and early-Jurassic dinosaurs together, for example showing Dilophosaurus living alongside the earlier Coelophysis bauri or the "prosauropod" Plateosaurus.

Dilophosaurus was first described in 1954 in Arizona from scant remains lacking the head, and was initially thought to be another species of the "wastebasket taxon" Megalosaurus. The first head complete with double crest was found only several years later; in 1970, the animal received the name Dilophosaurus, "double-crested lizard". Several footprints found in Early Jurassic terrains of the USA might have been made by dilophosaurs, but the exact identity of dinosaurian tracks cannot be told with certainty. One of these tracks was made by a swimming animal which barely touched the bottom with the tips of its feet.

Dilophosaurus had a brief role in the novel Carnosaur where it is resurrected via genetic splicing and later on goes on a rampage in London, it is portrayed the most accurately out of the reconstructions in the period being non-venomous and large like the real-life one. However, it's unlikely that many people outside the dino-fandom had ever heard of Dilophosaurus before the novel Jurassic Park was published in 1990 (years after Carnosaur was released itself). Here it was depicted as capable of spitting venom like some species of cobra, which it probably couldn't do in Real Life: venomous saliva is unknown among modern birds and crocodiles. Other much smaller theropods, like Sinornithosaurus and Scipionyx, were also believed venomous at one point, this time by scientists and not by pop-writers, because of some long acute teeth apparently looking like the snake's or Gila lizards' fangs; but there has never been real concrete proof of poisonous drooling in every theropod or non-theropod dinosaur.

Two years later, the JP movie made the dilophosaur even more popular and even more incorrect. Its size was greatly decreased ^note The dilophosaur who kills Dennis Nedry is smaller than a human, though the one portrayed might have been a juvenile as said by Nedry himself. Many think Spielberg reduced the animal's size to prevent the enlarged "raptors" from being overshadowed in viewers' minds., but above all, Spielberg added a totally improbable Frilled Lizard-like cowl on its neck. It certainly did not have this frill; it would require a lot of specific musculature on the neck, and the imprint of this would be visible on the skeleton (it isn't). Still, most later popular depictions have represented Dilophosaurus with this thing.

Just like Velociraptor, Dilophosaurus became a household name after the film, commonly known as the Spitting Dinosaur or simply the Spitter. Even though it did not reappear in the sequels until Jurassic World Dominion, the JP portrayal has remained in pop-consciousness so much that it prevented the Real Life animal from becoming more widely-known for long. One of the first venom-less/frill-less portrayals in TV was in the 2001 Speculative Documentary When Dinosaurs Roamed America, in which it is shown correctly in the Early Jurassic, and appears as the main predator of the story (the other predator is its smaller relative Megapnosaurus, identified with the old name "Syntarsus"). Today, the ever-increasing public interest in dinosaurs, mainly started thanks to Jurassic Park, is making Spielberg’s Mix-and-Match Critter more and more of a Lost Subtrope.

In 2020, a new discovery has partially thrown what we knew about Dilophosaurus out the window, namely the long-thought weak jaws and easily-breakable double-crest. The jawbones show they provided scaffolding for muscle attachment, meaning the jaws were actually powerful, the upper teeth behind the two "pits" were strong, and the crests were even possibly reinforced by a system of air sacs, perhaps used as an inflating or resonating or cooling system, like what has been classically hyped to explain the cranial shape of some hadrosaur ornithopods, like Edmontosaurus and Saurolophus.

1. Entry Time: 1990
2. Trope Maker: Jurassic Park (novel)

Other large theropods

Sorry, these ones aren't here. If you're looking for Alectrosaurus, Yutyrannus, Dryptosaurus, Eustreptospondylus, Monolophosaurus, Megaraptor, Gasosaurus, Irritator, Concavenator, Aucasaurus, Neovenator, and others, see here.

Toothed Bird-like Theropods

Several bird-like and bird-looking (usually small) theropods make appearances in media, although less commonly than the three "raptors" of the Great Stock section. Here we mention those with teeth: the toothless ones are in the following folder. Several toothy birdlike theropods here were related to dromaeosaurids, or were actually members of the group.

The "Big Brain": the Troodon/ Stenonychosaurus/ "Dinosauroid" Case **

Handsome Wounding Tooth/Unequal Narrow-Nailed Lizard

This has been a complex case of Science Marches On, but also an astounding example about how imagination can be a very influential factor even for people studying dinosaurs seriously.

Living in North America some 75 million years ago alongside giant tyrannosaurs, Stenonychosaurus inequalis/Troodon formosus was a small dinosaur, 8ft/2.4m in length and weighing some 110 lb./50 kg. Stenonychosaurus/Troodon was still the largest member of the troodontid family, a sibling family to Dromaeosauridae and among the closest relatives to birds. Troodontids looked a lot like dromaeosaurids, including being covered with feathers. Specifically, Stenonychosaurus/Troodon was rather similar in shape to the Real Life Velociraptor; you can tell apart the two by observing the "steno" 's shorter head, smaller teeth, eyes pointing forwards^note Most dinosaurs (dromaeosaurids included) had more lateral eyes, just like most modern birds and many herbivorous mammals today. Another famous example of a forward-pointing-eyes dinosaur is Tyrannosaurus rex., shorter tail, longer legs, and smaller weaker sickle-claws on their second toe.

Since the 1980s Stenonychosaurus/Troodon has attracted scientists' attention. Stenonychosaurus/Troodon shows several very specialized anatomical traits: it had larger eyes and ears than most dinosaurs, perhaps indicating nocturnal habits, and its brain was relatively large for a non-bird dinosaur as well. Its forward-pointing eyes show binocular vision similar to modern birds of prey; many old portraits showed it with bulbous eyes with cat-like or even gecko-like pupils, almost resembling humanoid aliens: remember that last detail, we'll return to it at the end. More realistically, it would have had bird-like eyes with round pupils. It used also to be imagined with opposable thumbs making its hands like an eagle's foot to better grasp its prey, but this is controversial.

The stenonychosaur/troodont's actual diet is still debated: with their surprisingly small & relatively blunt teeth, they were likely mostly-carnivorous omnivores, though they used to be portrayed as specialist small-prey hunters (nocturnal mammals, dinosaur nestlings, lizards, frogs, etc.). Some recently have even hypothesized they were herbivorous, but this is now mostly discarded. At the other extreme, some depictions attribute to them traditionally-dromaeosaurian traits such as pack behavior or the ability to kill large prey, which weren't possible in Real Life. Stenonychosaurus/Troodon's toothed jaws and sickle-claws were too weak to tear the meat of large living animals.

Now if you're wondering why we keep saying "stenonychosaur"/"troodont", there's a pretty convoluted story behind it. You see, the original find was a single tooth named Troodon formosus, "handsome wounding tooth", one of the very first North American dinosaurs found (1856), before Hadrosaurus but after Anchisaurus, see in other paragraphs. This tooth was initially believed from a lizard, then from a pachycephalosaur. Stenonychosaurus inequalis ("unequal narrow-nailed lizard") was described later than Troodon, in the 1920s, but classified as a generic "coelurosaur". In 1987, Canadian paleontologist Phil Currie found the two animals to be one and the same, and the name Stenonychosaurus fell in disuse in favor of the name Troodon, being created first. If you read popular dino-books written before the 1990s you'll probably find the name "Stenonychosaurus" more often, with Troodon usually appearing in offhand mentions as a "mysterious" dinosaur.

Suddenly, in the latter half of The New '10s, Troodon's validity was called into question, as the type specimen only consists of one tooth that cannot be distinguished on a genus level. As a result the name Troodon has fallen into taxonomic limbo; many fossils assigned to it have been moved into genera of their own (like Latenivenatrix and Pectinodon), while Stenonychosaurus has been resurrected, much as Brontosaurus was earlier in the decade. However, many popular works, including documentaries and non-fiction books, continue to use the name Troodon due to its recognizability in popular culture, with Stenonychosaurus having fallen into obscurity during the 90s and 2000s. But regardless of whether a work is calling the dinosaur Troodon or Stenonychosaurus, it's best to understand that they're referring to the same species of dinosaur 99% of the time. See also the even more complex case of Edmontosaurus/"Anatosaurus"/"Trachodon"/"Anatotitan" for comparison.

Moving on from this guy's complicated taxonomic history, scientists found in the 80s that the stenonychosaur’s braincase to be the biggest for its body size among all nonbird dinosaurs: this has given it the reputation of "the smartest dinosaur" in popular books, independently from if it was called either Stenonychosaurus or Troodon. Dromaeosaurids too have been classically depicted as very smart animals, but the troodontids were considered the biggest example among sickle-clawed dinosaurs in matter of intelligence. On the other hand, Pachycephalosaurus, despite its swollen head that make it looking like a genius-dinosaur, had a small brain for its size.

The stenonychosaur's real intelligence is today very debated: its brain actually was smaller than the one of many modern birds, and "big brain" doesn't mean automatically smartness. But also note that, despite the commonplaces, modern birds aren't foolish creatures at all: think about the parrots' ability to understand humans' feelings, or the ability of crows and other passerine birds to use tools to find food, or to mimic the ambient sound around them (especially able in imitating sounds is the large Australian male lyrebird, the biggest songbird in the world). This could mean the troodont might have been really a very intelligent creature, but its actual level of intelligence is not demonstrable from the fossils.

Despite the trend of The New '10s to show this particular dinosaur in documentaries, the troodont/stenonychosaur’s presence in fiction has been only occasional, and not related to the actual animal but to that could be called its "altmode". In 1982, when the time the animal was still called only Stenonychosaurus (and obviously portrayed as featherless), Canadian paleontologist and Phil Currie's colleague and friend Dale Russell conjectured a possible way that its descendants could have evolved had it not gone extinct along with the rest of the dinosaurs. If its brain had kept increasing in size, today it would have been comparable to a human's or even bigger. Combined with further evolution of its bipedal movement, binocular vision, and semi-manipulative hands, the resulting "Dinosauroid" was proposed to be a blend of featherless dinosaurian and humanoid features. This hypothesis was very popular in the eighties and nineties, to the point the animals itself has been modeled with humanoid traits like the aforementioned bulbous eyes and prehensile hands. The Dinosauroid has made a few appearances in novels and TV series; its Real Life dino-ancestor usually gets mentioned. It's also worth noting that the Dinosauroid model resembles the Sleestaks of Land of the Lost (1974) (1974-1977), possibly a case of Ascended Fanon. However, the design has been criticized by scientists for being too human-like, with many speculating that a sapient troodont descendant wouldn't look that much different from its ancestor. That hasn't really killed the popularity of the Dinosauroid in culture though, serving as the basis for countless dinosaur-based sapient races, ranging from reptilian aliens descended from dinosaurs that left Earth millions of years ago to malevolent lizard-men secretly controlling the government.

1. Entry Time: 1980s
2. Trope Maker: Its alleged intelligence inspiring the "Dinosauroid" hypothesis in the '80s and the works derived from it

The Original Raptor: Dromaeosaurus *

After the Power Trio made of Deinonychus antirrhopus, Velociraptor mongoliensis, and Utahraptor ostrommaysi, the most depicted dromaeosaurid in media has traditionally been the namesake Dromaeosaurus albertensis ("Alberta's running lizard"). The eponymy is not a mere case however. This was indeed the very first discovered dromaeosaurid: 1920s, in Alberta, and the generic meaning of "running lizard" is because its sickle claws were missing in its original skeleton, and scientists initially believed it was a small tyrannosaur or a more generic small theropod. The image of a hook-footed dinosaur came to light only after the description of Deinonychus in the sixties, and the family Dromaeosauridae itself was created around the same time to include Deinonychus, Dromaeosaurus, and Velociraptor together.

Dromaeosaurus was the same size of real-life Velociraptor but with a shorter head without the concave profile, and stronger jaws and teeth; compared with Deinonychus, Dromaeosaurus's head was smaller but with a wider snout (good comparisons with Utahraptor cannot be made because of the incompleteness of the latter's original skull). Appropriately for its name, Dromaeosaurus also had much longer legs than many of its relatives. In spite of being less-frequently portrayed than them, Dromaeosaurus appears regularly in dino-books and has also made some appearances in TV documentaries. If you see a dromaeosaurid interacting with Tyrannosaurus rex or Triceratops in Late Cretaceous North America, it would be Dromaeosaurus ^note To be correct, however, Dromaeosaurus lived a few million years before the end of the Cretaceous in which T. rex and Triceratops lived, but a dromaeosaurid that actually lived alongside T. rex and Triceratops was named in 2013: Acheroraptor. — unless the writers didn't know or just didn't care: some docs have shown Deinonychus or Velociraptor or even Utahraptor in this role. Walking with Dinosaurs dealt with the problem in a bizarre way: here, the dromaeosaurids are officially Dromaeosaurus… but have the shape of Deinonychus.

In truth, every dromaeosaurid in the original "Walking With series" was a Deinonychus, Utahraptors included. And to make the "Utahraptors" and the "Dromaeosauruses" distinguishable, they show up simply with a different coloration: the former brownish with black spots on its body; the latter blackish with a yellow-red tail tip like a coral snake. In this show, "Utahraptor"s are also portrayed in the way dromaeosaurids were once represented in paleo-art: naked-skinned, they chase an iguanodont in packs, jump on it using their sickle-claws as spurs, and eventually killing it with (a quite exaggerated) ease. Many dino-books have made this thing up to eleven with Dromaeosaurus, depicting scenes in which these turkey-sized predators chase and kill in packs adult Edmontosaurus and Triceratops 500 times heavier. Current paleontology suggests that Dromaeosaurus and the other “raptors” hunted smaller (but still large) prey and only ate the carcasses of the giant herbivores.

1. Entry Time: 1999
2. Trope Maker: Walking With Dinosaurs

Asian Pseudo-Bird Dinosaur: Saurornithoides *

Saurornithoides mongoliensis, meaning literally “Mongolian pseudo-bird lizard”, is the most known among the several Troodontid relatives, but unlike Dromaeosaurus, was found in Asia. It was originally called more simply "Ornithoides" ("pseudo-bird"), and shared the same Late Cretaceous habitat with two iconic similar-sized theropods, Velociraptor mongoliensis and Oviraptor philoceratops. Saurornithoides, Velociraptor, and Oviraptor were discovered together by the American expedition in Mongolia led by the famous adventurer and naturalist Roy Chapman Andrews in the 1920s, at the same time Stenonychosaurus was found in North-America. Like Dromaeosaurus, Velociraptor, and Stenonychosaurus, Saurornithoides was long considered either a peculiar "dwarf megalosaur" or a generic coelurosaur... until the 1970s, when it and Stenonychosaurus were put in their own family: the "Saurornithoidids", renamed “Troodontids” since the 1980s. Together, troodontids and dromaeosaurids made in turn the larger group called deinonychosaurians (lit. the "Deinonychus-like lizards"). Deinonychosaurs and dromaeosaurids are traditionally not the same thing: the former also include troodontids. Some analyses in 2013 have recovered troodontids as being avialans, in which case they would actually be closer to modern birds than dromaeosaurids, while other workers think they are neither deinonychosaurs nor avialans.

Traditionally, both Troodon/Stenonychosaurus and Saurornithoides have been depicted as cunning nocturnal hunters who used their large, forward-facing eyes with slit pupils, as well as their great intelligence to catch small mammals, grasping them with their three-fingered hands weaponed with curved claws and opposable thumbs. In reality, their eyes were bird-like with round pupils, their hands were not so prehensile, and their great smartness is not demonstrable (see Raptor Attack). Furthermore, according to recent research, at least Stenonychosaurus was more likely omnivorous a bit like ornithomimosaurs, because their teeth were tiny and not-so-sharp, resembling those of plant-eating dinos. Saurornithoides, having a slightly larger head and teeth than both, was more Velociraptor-like in external look (but not in its skeleton), and maybe it really corresponded to the former portrait of a specialized hunter. Some in the past have proposed that Stenonychosaurus and Saurornithoides are actually all synonyms, but today the saurornithoid is widely regarded as a distinct animal from its North American cousins.

1. Entry Time: 2009

2. Trope Maker: Clash of the Dinosaurs

Tiny Four-Winged Dinosaur: Microraptor *

Discovered in year 2000, Microraptor is one of the "Liaoning coelurosaurs", named “small thief”; as the "-raptor" suffix suggests, it was a dromaeosaurid. It was a find that surprised not only casual paleo-fans but also the entire paleontology community. And not because it was a feathered dino fossil (such animals were already known from the same site), nor just because it was the smallest non-avian dinosaur known at that point: merely 1.5ft long (but this record is contended now by other non-avian maniraptors and some primitive ornithischians). It was its unique body-plan that astonished us all: a four-winged dinosaur!

More precisely, its hindlimbs had a feather covering incredibly similar to that of its forelimbs, giving it its typical appearance. These wings had the same structure as the wings of true birds, with asymmetrical, vane-like feathers on the forelimbs, likewise on the hindlimbs, and placed in a "fan" at the tip of its long tail: in short, very similar to the kind of plumage of the well-known Archaeopteryx, itself recently found to have had remnants of such large feathers on its legs.

Of course, paleontologists and dino-fans have begun Wild Mass Guessing about its way of life. Since its discovery, Microraptor has been suggested to have been a tree-climber, with forelimbs as developed as the hindlimbs, both fitted with robust claws apt for climbing upright tree trunks; however, a study published in 2011 suggests it might have been terrestrial instead. The way it traversed the air is also controversial; with true flight like modern birds, or just simple gliding like modern “flying” squirrels, “flying” fish and “flying” lizards? Currently many scientists think Microraptor was actually a flier (although not as good as modern birds): it seemed to be even better adapted for flight than Archaeopteryx itself. If this is true, it would mean that flight evolved before the appearance of the so-called “first bird”, because Microraptor was probably less close to modern birds than Archaeopteryx was. And since flight was achieved in basal dromaeosaurids, this would mean that... yes, Velociraptor, Utahraptor, Deinonychus and all other dromaeosaurids may have descended from flying ancestors!

One scientist did go even further declaring that all maniraptorans descended from flying ancestors: this would mean, Troodon, Saurornithoides, Oviraptor, Citipati, and even the huge Therizinosaurus and Gigantoraptor were ancestrally creatures of the air, which, like ostriches or rheas, returned to a more ground-level way of life and increased their size. But all this is highly improbable.

Whatever the case was in Real Life, Microraptor immediately became the center of much interest soon after the year 2000, rapidly becoming popular in illustrated books — also because it was the considered the smallest dinosaur at the time; it became even more widely-known after being included as one of the main animal characters in the 2006 BBC series Prehistoric Park, where it was portrayed with the classic, splayed-hindlimbs gliding style, now known to be anatomically impossible. Soon afterwards, it started to gain attention in the broader pop culture world, and it has to at this point be qualified as a true Stock Dinosaur, even if only in the Rarely-Seen section, with one single star on the top. See "Guido" of The Land Before Time 12 for an example.

Another noticeable docu-portrayal is the one of 2011's Planet Dinosaur, in which it is shown as an agile glider but an awkward runner on land, obligated to hop like a sparrow instead of properly-running because of its long cumbersome feathers of the hindlegs. Note, however, that modern animals such as the gliding lizards like Draco or the gliding mammals like Cynocephalus, despite their prominent gliding membranes are nonetheless also good runners, thus it's possible that Microraptor didn't hop on land like many modern songbirds do, but ran just like the other dromaeosaurids.

Today three species of Microraptor are often recognized: M. zhaoianus is the original one, M. gui the second found, in 2003, and M. hanqingi, found in 2012. But some think there is only one species, M. zhaoianus. Other dromaeosaurids similar to Microraptor are known to science now (such as Hesperonychus, Sinornithosaurus, and Changyuraptor), all small-sized like it. Microraptor was even victim of one of the most astounding paleontological hoaxes of the New Millennium: see "The Archaeoraptor Fake". And as of 2012, we even know what color it is (it was a glossy shade of black), thanks to some exquisitely preserved fossils managing to preserve pigment cells!

1. Entry Time: 2006
2. Trope Maker: Prehistoric Park

Bird or Not?: Mononykus *

Mononykus ("one claw") was described in the early 1990s and originally called "Mononychus", but the genus name was preoccupied by a modern insect (a beetle to be precise). Its full binomial name is M. olecranus, and shared Late Cretaceous Mongolia with Tarbosaurus, Deinocheirus, Gallimimus, Therizinosaurus, and many other dinosaurs. Only 3 feet long, Mononykus surprised the scientists who found it in the early 1990s because of its absolutely unique, one-fingered hands with a large thumbclaw each: the other two digits usually present in coelurosaurian hands were simple stubs.

We still don't know how Mononykus could have used these "hands" that make it one of the most striking examples of the Hook Hand trope in the dinosaur world. Experts suspect it and its relatives, the alvarezsaurs, were specialized insect-eaters that broke open rotting wood with their claws to get at the termites inside (mound-building termites had not evolved yet), making them the dinosaur equivalent of anteaters. While this has not been wholly demonstrated, some scientists have pointed out evolutionary patterns among alvarezsaurs coincide with the evolution of social insects.

Interestingly, Mononykus was initially classified as the most ancient flightless running bird ever, not a bird-like non-avian dinosaur as we know today it was: thus, it has usually been depicted with feathers in illustrations since its discovery (despite the lack of any evidence of them in its fossil), like what happened with the apparently-similar neighboring dinosaur Avimimus (which did leave a fossil proof in the 1980s). Some portrayals show Mononykus toothless like a bird, while others show it with small teeth — sadly its skull is unknown (although we can make educated guesses based on its relatives).

Owing to the fragmentary nature of its initial remains and the aforementioned confusion regarding its classification, Mononykus depictions in popular books and other media during the 90s and 2000s are extremely inaccurate by today's standards, usually making it a man-sized, fast-moving, ostrich-like animal◊ similar to an ornithomimid. The best known example is in Chased by Dinosaurs, where Mononykus is also given teeth and is the only feathered dinosaur of the show, with Velociraptor, Therizinosaurus and Tarbosaurus portrayed totally scaly. Still, it remains the smallest dinosaur of the bunch here. Thankfully, our understanding of the alvarezsaur family has improved with new discoveries of related dinosaurs (including the realization that some other dinosaurs found around the same time, like Alvarezsaurus and Shuvuuia, the latter depicted in Dinosaur Planet, were part of the same group), with even possible Jurassic ancestors like Haplocheirus and Shishugounykus being uncovered. The current version of Mononykus is portrayed in 2022's BBC Prehistoric Planet, in the episode "Deserts" (which portrays also Tarbosaurus and Velociraptor). In this episode, the one-fingered animal is fully feathered, toothless, and properly sized, depicting it as the bizarre anteater-dinosaur scientists now believe it to be. Mononykus was a bit of a breakout star of the episode.

1. Entry Time: 2002
2. Trope Maker: Chased By Dinosaurs

Mix and Match Critter: Segnosaurus *

Most dinosaurs would appear as a bunch of Mix-and-Match Critters if alive today, with traits resembling those of mammals, bird, and crocodiles. But the Mix-and-Match Critter trope can also be applied in a more subtle way. Some relatively unknown dinos actually resembled strange mixes of more familiar dinosaurs, rather than modern animals. Segnosaurus galbinensis, Therizinosaurus cheloniformis and their relatives are perhaps the best example of this in the whole dinosaur world: another often-cited example is the sail-backed ornithopod Ouranosaurus, others are the giant non-predatory theropod Deinocheirus after the findings of The New '10s, and another fellow, Gigantoraptor, found in 2009.

Let's start with Segnosaurus. When the incomplete remains of it were discovered in the 1970s, hailing from Late Cretaceous Mongolia, this 24ft/7m long dinosaur made the scientists' eyes roll in their sockets: how could a dinosaur have the body-shape of a Plateosaurus, the forelimbs of a theropod, and an Iguanodon-like skull with a round bill at the front and grinding teeth behind? And, even though its pelvis was clearly saurischian in its overall structure, why did it have the pubis uniquely pointing backwards?

Taxonomists were totally confused, and finally placed Segnosaurus in its own group: the Segnosauria, along with three other less-known even more incomplete relatives (Erlikosaurus, Nanshiungosaurus, and the meaningfully-named Enigmosaurus), also Late Cretaceous and found in the same years of Segnosaurus in Mongolia or in China. The segnosaurians (lit. "slow lizards") were believed a separate evolutive branch which arose early in dino-evolution, and were classified in between theropods and sauropodomorphs, sauropodomorphs and ornithischians or sometimes even saurischians and ornithischians. Some even suggested they were late-surviving prosauropods related to the likes of Plateosaurus! A very similar scientific destiny occurred to the much smaller/ancient Herrerasaurians and Eoraptor, also described in the second half of the XX century in South America.

Science Marches On, however, and at the beginning of the 1990s, a much smaller relative of these segnosaurs, the 12ft/3.5m long Alxasaurus from Early Cretaceous China, clearly showed a coelurosaurian anatomy. This meant that segnosaurs were not only true theropods, but also members of the Maniraptoriformes, less-close to birds than oviraptorids and deinonychosaurs, but more than the ornithomimosaurs. Not only this: thanks to a more accurate comparison, it was discovered that the previously-enigmatic Therizinosaurus was another member of the same group - this had already been postulated before the nineties, but was still not demonstrable at the time. Today, Therizinosaurus, being bigger and weirder-looking, is more frequent in books than Segnosaurus and other members of the group, and the whole group is now officially named Therizinosauria in taxonomy, since Therizinosaurus was the first genus to have been described by science. Therizinosaurus too has had its own Science Marches On story, totally independent from that of Segnosaurus, and more similar to that of Deinocheirus. We'll get to that later. These days, Segnosaurus is usually just an aside name mentioned in dino-literature, a far cry from its frequent inclusion in popular dinosaur books of the 80s.

The diet of Segnosaurus used to be just as problematic as its classification. One early theory made it a fish-eater like Baryonyx and Spinosaurus, but slippery fish could have easily escaped from its round beak, and the theory was rapidly discarded. However, some paintings made in the eighties have shown Segnosaurus as a semi-aquatic fisher even with webbed feet: the last thing was based on alleged footprints. Indeed, the segnosaur had stockier hindlegs and shorter feet than most other theropods ("slow lizard", remember?), and with the usually-lifted fourth reversed toe of typical theropods touching the ground, to bear its higher body-weight compared with most theropods of similar length: but this doesn't mean it was like a wading bird such as a wild goose or a heron.

Another early unlikely hypothesis made segnosaurians ant-eaters and/or termite-eaters because of their large handclaws apparently apt to dig into ant-nests and termite-mounds; but again, these dinosaurs hadn't the typical tubular muzzle of a mammalian anteater, and such large creatures perhaps couldn't have lived on insects alone. ^note Interesting is that even Deinocheirus and Therizinosaurus were hypothesized to have been "prehistoric anteaters" only because of their big claws. Today, it's generally agreed that Segnosaurus and the other large therizinosaurians were specialized plant-eating theropods, strikingly convergent with ornithopods or early sauropodomorphs. This is the best theory also because it explains their backward-pointing pubis: its function was probably to give space to the massive gut of a herbivore without losing the bipedality of a theropod. Furthermore, other theropods with backward-pointing pubes are also known now, most of which are coelurosaurs, including dromaeosaurids and birds, though these appear to have acquired their backward-pointing pubes through a change regarding which muscles they used for running. Even though other birdlike theropods (ornithomimids, oviraptorids) could have eaten fruits or other kinds of vegetation, they were still omnivores, and only the most evolved therizinosaurians appeared specialized to a strict herbivorous diet based upon tree-leaves. If it wasn't for their unmistakably theropodian forelimbs and the fact that they had feathers, you could easily confound them with ornithopods like Iguanodon if they'd be alive today.

1. Entry Time: undetermined
2. Trope Maker: its traditional status of "the mix and match critter" dinosaur

Immense Nails: Therizinosaurus *

And now, Therizinosaurus: it could be considered a sort of twin of Deinocheirus for several reasons. It was colossal yet awfully bird-like, just like Deinocheirus; specialized to a non-big-prey-based diet, just like Deinocheirus; was discovered in Late Cretaceous rocks from Mongolia, just like Deinocheirus; is known mainly from forelimbs and few other bits, just like Deinocheirus before 2014; entered the dinosaur list around the same time as Deinocheirus; and, last but not least, it was another candidate for the title of biggest theropod, just like Deinocheirus! But, unlike Deinocheirus, Therizinosaurus was not a giant ornithomimosaur, but the biggest member of the Segnosaurians, today called Therizinosaurians.

Discovered in the 1950s but not recognized as a dinosaur until the 1970s, its forelimbs were slightly shorter but more powerful than those of the giant ornithomimosaur Deinocheirus. But Therizinosaurus had an additional curiosity: three scythe-like claws on each hand (hence its name, "scythe lizard"), some as long as a human arm. In short, it is believed to have had the biggest/longest nails known so far within the entire Animal Kingdom - even though some gigantic sauropods might have had even more massive thumbnails on their forefeet.

One of these oversized claws was in fact the first known find of the "therizino", and for several years, scientists thought it belonged to a giant marine turtle. Indeed, its fully scientific name, Therizinosaurus cheloniformis, means "turtle-shaped scythe lizard".

With such powerful weapons, Therizinosaurus has in the past received the same treatment as Deinocheirus. Some old drawings went as far as to show our "scythe-dino" as a giant carnosaur dwarfing T. rex or a huge deinonychosaur with sickle-claws on each foot: if Therizinosaurus was really shaped that way, it would really have been the most badass dinosaur one can imagine... This old-fashioned version of Therizinosaurus appears in the Dino Crisis video games. New discoveries of related dinosaurs made at the beginning of the 1990s definitively debunked these fantasies: we now know with a good level of certainty that Therizinosaurus was a bulky-bodied, round-bellied, and quite slow-moving animal that used its claws mainly to pull down branches. Furthermore, its jaws were arguably weak with a rounded horny tip and small grinding teeth similar to those seen in its smaller but scientifically better-known relative Segnosaurus. With Therizinosaurus being the bigger of the two (and usurping Segnosaurus as the namesake of its group due to seniority), "Therizino" has gone on to become a mainstay of popular dinosaur media, with "Segno" fading into obscurity, even despite the fact Therizinosaurus is still known from mostly incomplete fossils.

Despite the paucity of Therizinosaurus remains and the fact it was actually a veggie-eater, this doesn't lessen its general coolness: even with this new shape, Therizinosaurus remains an odd-looking, powerful beast, and thanks its massive body, it might even be the heaviest theropod ever discovered, weighing even more than the longer but slenderer Spinosaurus: but this is not demonstrable for now obviously, due to its fragmentary fossils. Therizinosaurians, because of their shape and habits, have often been compared by scientists with giant mammals, like the ground sloths such as Megatherium, or the less-familiar Chalicotherians, see Stock Dinosaurs (Non-Dinosaurs). Some have even compared them with giant pandas or gorillas.

As we've long done with Deinocheirus, we dino-fans are patiently waiting for exciting new remains of our "Wolverine Claws-osaurus" to be excavated. Meanwhile, Chased by Dinosaurs from 2002 temporarily recreated our imagination in CGI: in the episode titled "The Giant Claw" Nigel Marven talks about Therizinosaurus, lampshading its whole Science Marches On story from a mighty carnivore to a Gentle Giant. Nigel is in Late Cretaceous Mongolia searching for the possessor of the eponymous "giant claw", which the zoologist believes to have pertained to a fearsome predator. After several adventures with other dinosaurs of the habitat (Saurolophus, Protoceratops, Velociraptor, Mononykus), Nigel witnesses a fight between Therizinosaurus and Tarbosaurus: even though the former unexpectedly reveals itself to be an herbivore, it easily defeats the tyrannosaur by slapping it in the face with its enormous scythe-claws, obliging the predator to flee. Finally, the therizinosaur licks Nigel’s face. Really! Unfortunately, Nigel's "therizino" lacks the coat of feathers we know it would have had, based on smaller relatives from Early Cretaceous China.

In 2022, Therizinosaurus finally made its mainstream pop culture debut in Jurassic World Dominion, where it was given a coat of feathers (although not to the same degree as it would have had in reality) and extremely improbable echolocation abilities. Depicted as a Xenophobic Herbivore (possibly as a nod to it being a theropod, thus related to carnivores like T. rex and Velociraptor), it engages in a three-way battle with T. rex and Giganotosaurus, killing the latter with its iconic Wolverine Claws. However, time will tell if "therizino"'s Hollywood debut will launch it into super stardom the same way Spielberg's franchise previously did for raptors and Spinosaurus. Around the same time, a much less aggressive Therizinosaurus appeared in Prehistoric Planet, most centrally in the Forests episode, which featured three juveniles attempting (and failing) to raid a beehive for honey.

1. Entry Time: The 2000s
2. Trope Maker: Chased by Dinosaurs

Other toothed birdlike theropods

Sorry, these ones aren't here. If you're looking for Caudipteryx, Sinosauropteryx, Beipiaosaurus, Sinovenator, Achillobator, Saurornitholestes, Pelecanimimus, Nothronychus, Alvarezsaurus, Shuvuuia, Bradycneme, and others, see here.

Toothless Bird-like Theropods

The most known birdlike theropods lacking true teeth belonged to the ornithomimosaurs and the oviraptorosaurs, which didn't form a natural group together. Ornithomimus, Struthiomimus, Dromiceiomimus, Gallimimus, and huge Deinocheirus have been the most known members of the first subgroup; the small Oviraptor/Citipati and the bigger Gigantoraptor are today the most familiar of the second one. Among the latter, the tiny Avimimus owes the record of "the first known feathered nonbird dinosaur" (if you don't count the classic "missing link" Archaeopteryx).

Lighter and Faster: Ornithomimus, Struthiomimus & Dromiceiomimus **

Tall Ostrich Mimic

Before Jurassic Park made the "raptors" popular in The '90s, ornithomimids used to be the animals that most often came to mind to people when thinking about small & agile dinosaurs, as the antithesis to the classical Mighty Glacier image.

Ornithomimus velox ("fast bird-imitator"), the prototype of the family, lived in North America between 75-66 million years ago, in the Late Cretaceous. It was 12 feet/3.5 meters long and weighed around 220-330 lbs./100-150 kg. Its shape was similar to a long-tailed ostrich. It had a long neck with a birdlike skull and a toothless beak. The brain and eyes were large (though not the same degree of troodonts), possibly an adaptation to support quick movement. Its body was short and compact, like that of a bird. Its tail was very long, balancing the animal when running. The legs were similar to modern running birds, with short muscular femurs, elongated tibias/shins, and three toes each (not four: it lost its reversed toe during its evolution). With this anatomy it may have been among the fastest non-avian dinosaurs, easily capable escaping the bigger and clumsier Tyrannosaurus rex.

Ultimately confirmed to be feathered, which was already suspected for some time. It certainly had down-covering; the adult specimens were argued to also have shafted feathers (similar to covert feathers of birds) on their forelimbs that most likely formed a wing-like structures called pennibrachia (though obviously not used for aerial locomotion).^note  The presence of the latter feathers, however, was only inferred on the basis of markings on its forelimb bones, and it has also been argued (p. 18) that, instead of covert-like feathers, Ornithomimus might have had thick filamentous feathers on its forelimbs. So far only When Dinosaurs Roamed America, Prehistoric Planet, and the 2006 remake of the first Doraemon movie had appearances of a fully-feathered Ornithomimus, before it was confirmed that this dinosaur had feathers, (although it was only identified on the former's website).

Ornithomimus is the archetype of the Ornithomimids, often nicknamed "Ostrich-dinosaurs" or "Ostrich-mimic dinosaurs". This family also includes its neighbor Struthiomimus altus ("tall ostrich-mimic") and other animals like Gallimimus bullatus. Struthiomimus was identical in shape and size to Ornithomimus: it had only longer forelimbs and bigger hands and handclaws. Struthiomimus was just as fast and quick as its Non Identical Twin Ornithomimus, and lived in North America in the same period: the two were actually considered the same animal at the time ornithomimids first entered pop-media, in 1940, and were definitively recognized as distinct only in the 1970s.

As their names suggest, Struthiomimus and Ornithomimus have unusually been recognized as birdlike dinosaurs since their very first discovery. Ornithomimus was the first described (USA, 1890, during the Bone Wars), while Struthiomimus was named later (Alberta, 1917). The first U.S. remains were fragmentary, though, and complete ornithomimids came to light only in the early 20th century. They were described as fast-moving and graceful even before the Dinosaur Renaissance, and usually portrayed with erect tail and horizontal body, unlike the giant bipedal dinos with their upright bodies and dragging tails.

Unusually for dinosaurs, media have never shown ornithomimes as scary killers dangerous to humans. This can be due to their lack of teeth that make them look harmless. Their actual diet is still uncertain, as no stomach remains are known for now. Their large numbers, among other things, seems to indicate that they were mainly herbivorous with insects, eggs, and small animals as a supplement, much like modern ostriches. In popular media they have often been depicted as plant-eaters and/or insect-eaters, very rarely as meat-eaters, and one memorably appears as prey to a much bigger theropod in The Valley of Gwangi. But the most common pop-portrayal has shown them as egg-stealers outwitting larger dinosaurs.

One good example is in The Land Before Time series. In the original movie of the Land Before Time franchise unnamed ornithomimid attempts unsuccessfully to steal Littlefoot's egg, while in the second episode of the series two villainous egg-stealing Struthiomimuses are named Ozzy and Strut: a case of A Lizard Named "Liz", as Ozzy is arguably derived from "Ornithomimus", and Strut is clearly the initial of "Struthiomimus". Even though they might have eaten some eggs, there is no evidence this was a major part of their diet. Furthermore, not being maniraptorans ("robbing hands"), they probably couldn't grasp things so easily as the latter did. Today in popular media the "robbing" role can be also attributed to other small theropods, like oviraptorids. Finally, in the early 2000s it was suggested ornithomimids were filter-feeders like flamingos, as seen in Prehistoric Park, but now this hypothesis is totally disproved by Science Marches On.

Another stock ornithomimid, Dromiceiomimus, has a rather tongue-twister name, but it simply means "emu-mimic". Dromiceius novaehollandiae is the old scientific name of the emu: it's now Dromaius novaehollandiae, both meaning "Runner of the New Holland" (the old name of Australia). It lived in Late Cretaceous North America together with Ornithomimus and Struthiomimus. It was almost identical to the former in size/shape, but with longer legs and wider eyes: dino-books have often mentioned the Dromiceiomimus as "the fastest dinosaur", able to run 70 km per hour like a running horse or ostrich, or "the biggest-eyed dino" (in respect to the body) because of its huge orbits. Found in the 70s, well after its two neighbors, in the 2000s and 2010s it has been suggested to be a second species of Ornithomimus, O. edmontonicus. It is also one of the three characters of the webcomic Dinosaur Comics together with T. rex and Utahraptor.

1. Entry Time: 1940 (Ornithomimus/Struthiomimus)
2. Trope Maker: Fantasia (Ornithomimus/Struthiomimus)

Brooding or Robbing, Lord or Thief: Citipati, going by the name of Oviraptor **

Osmolska's Pyre Lord; NOT Horned-faced Loving Egg Thief

Oviraptor lived in Late Cretaceous Asia 75 million years ago. This very bird-like dinosaur is another excellent demonstration about how Science Marches On is a crucial factor in popular dino portrayals.

First discovered in Mongolia in 1924 together with Protoceratops and Velociraptor, this toothless theropod was originally thought to be an ornithomimid. Since the 1970s it is classified into its own family, even more closely-related to birds. Oviraptor was distinct from ornithomimids by having a rounder, stockier beak, a shorter tail, and the small fourth reversed toe on each foot present in most theropods (birds included), which was lost in many ornithomimosaurs. Unlike the latter, the oviraptor was a maniraptoran theropod: its forelimbs were bird-like, and it's considered to have had a very bird-like covering of feathers, with feathered wings and a feathered tail fan.

It was given the name Oviraptor philoceratops, meaning "ceratops-loving egg-thief", because the first specimen, a crushed skull, was found next to a clutch of eggs which were thought to belong to the small ceratopsian Protoceratops. In the 1990s, the eggs were found to contain Oviraptor chicks: the specimen was brooding its eggs. This was further confirmed few years later, when an oviraptorid skeleton was found just above a nest full of the same kind of eggs. Still today, scientists continue to find oviraptorids nests in Mongolia or in China.

Before the mid 90s scientists used to describe Oviraptors as specialist nest-robbers, and documentary works have typically shown them frequenting the nesting ground of herbivorous dinosaurs (especially those of Protoceratops), grasping the eggs with their prehensile hands, and fleeing away from the angry mothers when they're discovered. The "robbing" behavior has often been attributed both in science and in popular culture to ornithomimids as well, but the oviraptors were considered specifically adapted just to eat eggs and no other kind of food unlike the more omnivorous ornithomimes, and the robust bill of the oviraptors, complete with two piercing "palatine teeth", was thought a specialization for breaking eggshells. Today, the actual diet of oviraptorids is a matter of speculation — they might have been fruit-eaters, predators, or both; they might even have fed on eggs if given the chance, like possibly every small toothed or toothless theropod. But regardless of diet, the rules of taxonomic naming mean that the appellation of "egg-thief" has stuck, no matter how unfitting it is.

Since the first discovery the oviraptors have also notably changed their look: paleo-artistic works from before the 1990s usually depicted them featherless, and with a protruding palate with a pair of "teeth" at the tip (the palatine teeth), believed apt to break eggshells like what happens in the stomach of the egg-eating snake (Dasypeltis) of Africa. In works made in the 80s and the 90s, you can see the oviraptorid with two different head-shapes: the one with a small bony bump on its nose (the more classical original one, but inaccurate), and the one with a square bony flat crest, first emerged in the 1970s. This is the most common image today in paleo-works, see also Prehistoric Life to go deeper within the argument.

However, since the 2000s, the most complete Oviraptor skeletons have been reclassified in a brand new genus, the non-Latin-sounding Citipati, after twin funerary gods in Tibetan Mythology: the familiar square-crested image belongs to this new genus. Note that this is not the classic "Brontosaurus"/Apatosaurus case: the genus Oviraptor is still valid, with the only species O. philoceratops; it's just that many specimens that used to be considered to belong to the genus are now considered Citipati osmolskae, and that the actual Oviraptor is very unlike its depictions, lacking any known crest and being far smaller than its emu-sized relative.

Although it had a long history of appearing in popular dinosaur books, unlike ornithomimids, oviraptorids only attracted the attention of popular culture only since the 2000s: after the appearance of the feathered, non-egg-stealing scientific depiction. And yet, expect to see them portrayed in the older, now inaccurate way nonetheless, and you can easily see oviraptorids and ornithomimids mixed up with each other. See the 2000 Disney movie Dinosaur, where a featherless "Oviraptor" steals Aladar's egg, but loses it before it has a chance to eat the contents. More recently, an "Oviraptor", named Ruby thanks to her color, appeared in The Land Before Time TV series: feathered and not egg-stealing. Both portrayals show the Oviraptors with a Citipati-like tall crest on their head. Meanwhile, Dinotopia lampshades the animal's Science Marches On story showing it in two variations: the featherless "Oviraptor" and the feathered "Ovinutrix" ("egg-nurse"). This dinosaur entered (with feathers) the JP franchise in 2022, thanks to Jurassic World Dominion.

1. Entry Time: 2000
2. Trope Maker: Disney's Dinosaur

A Bigger Runner of Asia: Gallimimus **

Discovered in the 1970s — much later than the two classical ornithomimids Ornithomimus and Struthiomimus — Gallimimus means "rooster-mimic", and was one of the largest ornithomimids: 20ft/6m long (like a Dilophosaurus or Ceratosaurus), with some reports of sizes up to 8 meters long, as long as some giant predatory theropods like Albertosaurus or Megalosaurus but still less-heavy than them due to its lighter body-frame.

It lived in Mongolia in the Late Cretaceous, 70 mya, together with Therizinosaurus and its cousin Deinocheirus, and its full scientific name is Gallimimus bullatus. Apart from its longer, wider, and blunter snout and slightly shorter legs, its appearance was that of an enlarged Ornithomimus or Struthiomimus, with small short forelimbs more similar to the former than to the latter. It belonged to the same family of its smaller North American cousins, sharing with them the same skeletal anatomy: lack of teeth, long ostrich-like neck, and absence of the fourth toe in the foot. Despite its size and weight (500 or more kgs) it was probably as fast and agile as them, and also its behavior in life was arguably similar. Obviously, it's hard to determine which ornithomimid was the fastest runner due to lack of fossil evidence. An interesting thing to note is that the ornithomimids had lateral eyes like most modern herbivores, not forward-pointing like typical carnivores — contrasting, for example, with Tyrannosaurus and Stenonychosaurus.

With its large fossil record Gallimimus has become a common sight in dino-books since the '80s, just as common as Struthiomimus and Ornithomimus, and entered the pop-consciousness in 1993 after Jurassic Park — the film, not the novel, which has the ornithopod Maiasaura in the stampede scene. Here, a flock of Gallimimus is seen fleeing from the protagonistic Tyrannosaurus who manages to capture one (an homage to the Ornithomimus scene in The Valley of Gwangi described above). In the movie, however, this dinosaur has an overall secondary role in respect to the other dinosaurs portrayed (except for Parasaurolophus, that makes only a cameo before the appearance of the toothless dinosaur). Both the ornithischian Parasaurolophus and the saurischian Gallimimus reappear in the 1st sequel in 1997 during the "dinosaur hunt" scene, together with Pachycephalosaurus and Mamenchisaurus; this time, however, the ostrich-dinosaur is not named. Other Gallimimuses named "rainbow faces" show up in The Land Before Time 7 as helpers of the protagonists in the 2000s. Like Velociraptor and Dilophosaurus, Gallimimus became one of the better-known dinosaurs after the 1st Jurassic Park movie, but has not replaced Ornithomimus and Struthiomimus in pop-culture. Fictional works from after 1993 can still add Ornitho- or Struthio- (or even "Dromiceio-") to their -mimuses, instead of Galli-.

1. Entry Time: 1993
2. Trope Maker: Jurassic Park film

The Big Mystery Resolved: Deinocheirus *

Most bird-like dinosaurs were small and unimpressive in Real Life compared to most other dinosaurs. This definitively couldn’t be said for Deinocheirus, living in Late Cretaceous Mongolia. Like Therizinosaurus, it is among the largest known theropods, and both were similar in size to Tyrannosaurus rex.

Deinocheirus mirificus means, “astounding terrible hands”, and should not be confused with Deinonychus antirrhopus, “counterbalanced terrible claw”. It was discovered in the 1970s in the Gobi Desert during an unusually rainy day for such an arid location, by the same Polish expedition that found the Protoceratops/Velociraptor fossilized battle and many other dinosaurs.

Only its complete forelimbs were found by the scientists, along with three-fingered hands, shoulder-blades, and some other fragments from the rest of the skeleton. The leading scientist of the expedition, Halszka Osmolska, noted that these forelimbs were similar in shape to those of an ornithomimid... only, they were twice the height of a fully grown human. To give you an idea of the scale, several drawings have then shown these immense “arms” encircling an adult human, with the three-fingered hands (each as wide as a big TV-set) shown like they’re going to grasp and then lift him/her. The documentary Planet of Dinosaurs is a good TV example of this. The drawings usually didn’t show the whole body, because its shape was totally unknown.

After the discovery, a veritable Wild Mass Guessing started to understand what sort of thing Deinocheirus looked in life. Just as an example, some thought it had forelimbs longer than the hindlimbs: but this wasn't so, since this would have forced the animal to walk on four legs — an impossibility, since its hands were inapt for walking. We now know Deinocheirus had the same bipedal body shape of the classic theropods. Speculations about its size abounded as well. If its forelimbs had the same proportions of a Gallimimus, then Deinocheirus could have been bigger than a T.rex, and maybe as long as a Spinosaurus — and even taller, thanks to the longer neck. It was even said that it could reach the fourth story of a building if alive today, and could have weighed as much as two elephants, that is to say, two T. rexes. But most experts didn’t agree with these extreme ideas, and put Deinocheirus in the same size-range as Tyrannosaurus or Allosaurus. Moreover, being an ornithomimosaur, it was imagined rather slender-framed, and thus unlikely that was as heavy as two elephants: perhaps even lighter than T.rex.

And then, there has been all the speculation about its way-of-life. Early reports described it as a gigantic predator, but such an image was usually believed highly unlikely. Scientists didn't know if Deinocheirus was a basal toothed ornithomimosaur, or a derived toothless one: most agreed it should be put in its own family, the deinocheirids, outside ornithomimids proper, or even in its own suborder, Deinocheirosauria (distinct from Ornithomimosauria). If the toothy version was true, it could have been an active hunter, and someone could have even imagined titanic battles against the contemporaneous T. rex relative Tarbosaurus or even Therizinosaurus, also often imagined a giant active predator at the time. But even with sharp-toothed jaws, Deinocheirus shouldn’t be seen as such a powerful killer. Its jaws and teeth would be much smaller and weaker than tyrannosaurs', carnosaurs', or even spinosaurids'. Furthermore, its one-foot long handclaws are too blunt to be able to rip the tough skin of a hadrosaur or a sauropod. The main consensus was Deinocheirus was a sort of giant omnivore, which could have eaten from tree-tops using its forelimbs to pull down branches like a mammalian giant ground sloth or a chalicothere (convergent evolution), and at the same time could have scavenged carrion of large herbivores, destroyed ant-mounds and termite-mounds like an anteater or a pangolin, hunted small dinosaurs that could be swallowed whole, and maybe chased Tarbosaurus away from their kills using its “terrible hands” as a scaring device. Therizinosaurus got a similar description until The '90s.

To resolve the mystery, dino-fans patiently waited for a complete Deinocheirus skeleton for many, many years. Material described in 2012 was a step in the right direction: this shows that the original incomplete carcass was scavenged by a Tarbosaurus. But in the 2013, after 40 years of waiting or so, the so-much attended answers arrived at last. Two almost-complete specimens of Deinocheirus were found near the original one: they weren't found by the Polish scientists by misfortune.

This new material confirmed and debunked all the hypotheses above: Deinocheirus was really an ornithomimosaur, but displays a feature unknown in any other birdlike theropod: a sail that peaks over the hips, similar in shape to that of the carnosaur Concavenator. In 2014, its skull was found, which resembled that of the duckbilled hadrosaurs but with no teeth or bony crests. In the same year, new evidence emerged revealing that Deinocheirus had a thicker lower jaw than previously thought, and fish remains were discovered in one specimen's stomach. This suggested that Deinocheirus was an omnivore that mostly fed on ground level and aquatic vegetation and also ate small animals when it could.

Deinocheirus, in addition, became the largest dinosaur with evidence of feathers, as its tail showed pygostyles where feathers were attached, proving again than size did not rule out feathers, as the tyrannosaurid Yutyrannus had already demonstrated two years before — after all, modern elephants, rhinos, and hippos do have hair just like every other land mammal, just very sparsely. It was also revealed that the much smaller Beishanlong and Garudimimus were the closest relatives of Deinocheirus, forming the family Deinocheiridae (whose Deinocheirus was originally believed the only member), thus putting the latter very close to true ornithomimids in the evolutionary tree.

Described officially in October 2014, the two new specimens were slightly bigger than the original one, and indicate that Deinocheirus actually was one of the biggest and tallest theropods ever: about 6-7 tons like a big T.rex, more robust than typical ornithomimosaurs, and one of the biggest animals of its fauna, the weight of a small titanosaurian sauropod like Opisthocoelicaudia, thus outweighing and potentially outmighting its possible predator Tarbosaurus, and living peacefully alongside the plant-eating Therizinosaurus. In short, Deinocheirus mirificus instantly went from being one of the biggest paleontological mysteries of the 20th century to an animal whose appearance and lifestyle are well understood - quite possibly one of the greatest stories of Science Marches On in the history of dinosaur discovery.

After many years of being popularly hyped up in dino-books as the most mysterious dinosaur (with the few artists who did try to reconstruct it depicting a T. rex-like monster, a suspiciously Therizinosaurus-like animal, or simply a ridiculously oversized Gallimimus), Deinocheirus finally made its media debut in the Curiosity Stream / NHK collaboration Amazing Dinoworld and on TV in the 2022' BBC documentary Prehistoric Planet, both of which portray it with the strange new look and swamp-dwelling lifestyle discovered by the scientists in the 2010s.

1. Entry Time: 1980s
2. Trope Maker: The mystery of its appearance

Gigant(ic) O(vi)raptor and Tiny Bird Mimic: Gigantoraptor & Avimimus *

Oviraptor relatives were small-sized like their group's namesake: the biggest, Anzu wylei, was only a bit larger than an ostrich. But this is only if you don't count Gigantoraptor erlianensis. Discovered in Asia in 2007, this dinosaur, despite its name ("gigantic thief"), is not an overgrown dromaeosaur, but an overgrown oviraptorosaur.

The holotype specimen of Gigantoraptor was 25ft / 8 m in length, and said skeleton (the only one of this dinosaur known to date) was of a teenager; a fully-grown adult could have potentially rivalled T. rex in size. The Gigantoraptor had the anatomy of the classic oviraptorosaurs; if the oviraptorosaurian way of life has been hard to decipher (some hypothesize to have them being originally herbivores, but re-evolving into pure carnivores), imagine what kind of headscratching Gigantoraptor caused. It's all cool, though: three, generally small-sized lineages of non-avian coelurosaurs have a few oversized members within their ranks: Deinocheirus the giant ornithomimosaur, Utahraptor the giant dromaeosaur, and Gigantoraptor the giant oviraptorosaur. On the other hand, tyrannosaurs and therizinosaurs include many gigantic species, while other coelurosaurs, such as the troodonts and alvarezsaurs, have none. But who knows? Maybe one day a “Gigantroodon” would be discovered...

Together Deinocheirus, therizinosaurids, and Gigantoraptor make a strange case: such overgrown birdlike theropods seem an almost only-Asian affair, and nobody knows why similar animals have never been found in North America except for the early therizinosaur Nothronychus — considering the strong similarity of the two faunas in the Late Cretaceous, which would have regularly exchanged animals through the Bering Land Bridge. Maybe the competition with the almost-exclusively American ceratopsids could have prevented North American birdlike theropods from reaching larger size? And even this idea has problems, since we now know that there were a few ceratopsids in Asia, like Sinoceratops. Additionally, discoveries of massive oviraptorosaur eggs in North America similar to those of Gigantoraptor (which interestingly had been known for over a decade before their parent was discovered) and possible therizinosaurid footprints in Alaska suggest maybe there were giant bird-like theropods in North America, and we just haven't found their bones yet.

Like Therizinosaurus, only parts of the skeleton of the gigantoraptor is known for now. While Deinocheirus was an omnivore, and Therizinosaurus and kin were herbivores, Gigantoraptor has still no consensus regarding its diet. Its closest relatives (known as caenagnathids, a sister group to the oviraptorids within oviraptorosauria) show predatory adaptations and are known to have eaten small prey like lizards, and this is the most likely option so far, but considering that it's another giant "freak" nobody can be sure.

Despite being a very recent find, Gigantoraptor soon received some mild media attention, appearing in the early 2010s in paleo-documentaries, Planet Dinosaur and Dinosaur Revolution. The awesomely-named Gigantoraptor is on its way to becoming a minor Stock Dinosaur.

But when did the Great Feather Adventure begin? The answer: in 1981, in the Mongolian Gobi Desert, the same place where Oviraptor and Velociraptor were first discovered. That year, a new kind of Late Cretaceous “coelurosaur” was described from a partial skeleton, which astonished the scientist who found it. He chose to name his find Avimimus - “bird mimic”, the same as Ornithomimus, only with a Latin prefix instead of Greek. Despite this, Avimimus was not an ornithomimid, but an only 5 ft / 1.5 m long, late-surviving basal oviraptorosaur only a bit bigger than a Compsognathus. Nothing special per se... except for one thing: it was the very first dinosaur whose skeleton showed some evidence of feathers. Not prints on the rock, however, only a crest on its arm-bones that resembled that of modern birds.

For about 12 years since then, Avimimus has been the only non-avian dinosaur regularly portrayed with feathers – often in an incorrect way: certain depictions first popularized by John Sibbick in the 1985 Dinosaur Encyclopedia showed it as a short-winged Archaeopteryx with the same head-shape, jaws filled with teeth, blue color, and splayed forelimbs, as if was about to take off. It actually had a short head and short arms typical of oviraptorosaurs, so it couldn’t fly. However, Avimimus lacked a crest on its head, and also had serrations in its beak which could have worked as teeth.

The full scientific name of this small but historically important dinosaur is Avimimus portentosus, "marvelous bird-imitator", underlining the relevance of its find and the subsequent implications about the Feather Theory, which has already been postulated since the seventies but without any concrete clue before that.

1. Entry Time: 2010s (Gigantoraptor); undetermined for Avimimus
2. Trope Maker: Planet Dinosaur and Dinosaur Revolution (Gigantoraptor); its status of "the first dinosaur with proof of feathers" (Avimimus)

Other toothless birdlike theropods

Sorry, these ones aren't here. If you're looking for Garudimimus, Chirostenotes, Archaeornithomimus, Anzu, Conchoraptor, Rinchenia, Nomingia, Anserimimus, Sinornithomimus, and others, see here.

Other Non-Bird Theropods

These dinosaurs were generally less-close to birds than the ones in the previous two folders. All lived earlier than them, in Jurassic or Triassic and not in Cretaceous, but they tend to be equiparated with them in media because of their slender shape and small size.

Cannibal or Ancient Hero?: Coelophysis **

Baur's Hollow Form

One of the first true dinosaurs to appear on Earth, Coelophysis bauri lived in Late Triassic North America 216-203 million years ago: fragmentary material suggests a near worldwide distribution lasting up to 188 mya, in Early Jurassic: Megapnosaurus (that lived in Africa and possibly North America) is thought by some to belong to the Coelophysis genus. This animal was once classified as "Syntarsus", see here.

Described during the Bone Wars from some pieces of bone by Edward Cope, today Coelophysis bauri (Baur was one of Cope's helpers) is by far the most abundant early theropod in the fossil record. In the 1940s, a whole graveyard with hundreds of specimens was found in New Mexico; they're widely theorized to have died all together in a flood, though this is not certain. This was one of the first dino-graveyards ever found from the Triassic, after those of Plateosaurus found in Europe at the start of the century.

Coelophysis was a slim, fast-running dinosaur growing up to 10ft/3m, and weighing about 30 kg. Coelophysis looks like a fragile animal, with a narrow head, weak jaws with small pointed teeth, a long, stork-like neck (often incorrectly described as "snake-like" in popular dinosaur books), an elongated, thin body, and a long, slender tail. As an early theropod, Coelophysis was not very closely related to birds. For example, it had still a remnant of the fourth digit on each hand, and the presence of feathers is not proven. If it had them, they were surely "proto-feathers" or down-like structures, not modern-looking feathers. Still, it had bird-like features showing how far back in time the dinosaur-bird link goes. Its skull and hindlegs were similar to the more evolved theropods; its bones were hollow and had air sacs within them (Coelophysis just means "hollow frame"); and it even had a tiny wishbone, a typically avian trait, discovered only in 2007 because of its smallness. Originally, it was accepted that non-bird dinosaurs were all wishboneless except for some birdlike theropods, e.g. the oviraptorosaurs and the "missing link" Archaeopteryx.

Coelophysis probably hunted down small prey, which it swallowed whole: lizards, dinosaur nestlings, fish, insects, protomammals, and whatnot. In the Triassic, the top predator role was played by non-dinosaurian archosaurs like Postosuchus or Rutiodon, or larger theropods like Gojirasaurus. Coelophysis bauri is often described as a "successful underdog" which finally managed to outcompete non-dino archosaurs, anticipating the following domination of the dinosaurs in the Jurassic world. It is usually portrayed as a gregarious animal that lived and sometimes hunted in packs; although pack behavior is possible, pack-hunting is unlikely.

In many works it's said adult Coelophysises ate younger members of their own kind, or even their own offspring, during famines. This is because bones found in the stomachs of adult specimens from the aforementioned "graveyard" in New Mexico were reported to belong to young Coelophysis, leading to the dinosaur being described as cannibalistic. Later studies from the 2000s have determined that the bones in question were animals of other species, possibly the small semi-bipedal crocodylomorph Hesperosuchus among them. This doesn't mean that Coelophysis didn't occasionally eat their own kind (crocodiles and eagle-nestlings do this after all); only that there isn't any fossil proof anymore.

Together with the large herbivorous Plateosaurus, Coelophysis is the dinosaur you're most likely to see in those documentary works portraying the Triassic Period, to show how the earliest dinosaurs looked — even though in Real Life there were many other dinos in the Triassic, some even more primitive: herrerasaurians like Staurikosaurus and "prosauropods" like Thecodontosaurus are two examples of the latter. In these works, the smaller Coelophysis is used to represent the very start of the dinosaur evolution, while the bigger Plateosaurus represents a more advanced/enlarged stage. An excellent example of all this is the first episode of the TV documentary Walking with Dinosaurs, in which the two animals are shown living together in North America: in Real Life only the Coelophysis was North American, the plateosaur was found in Europe. In the show the Coelophysis is portrayed cannibalistic during the worst part of the world-famine, but it's not said if the adult specimen eats one of its own young, or the chick of another adult individual.

Coelophysis has been far less common in fiction or other more popular media, since it is too humble-looking and generic by dino-standards to be interesting; the best-known appearance may be "Spot" from Land of the Lost (1974).

1. Entry Time: 1974
2. Trope Maker: Land of the Lost (1974)

Dinosaurs as Pets: Compsognathus **

Long-Footed Elegant Jaw

Compsognathus longipes was native to Europe 150 million years ago and lived alongside the famed "first bird" Archaeopteryx, in the same habitat made of small islands. Like the "Urvogel", it was one of the first dinosaurs described, in the same year as the latter. The first Compsognathus specimen was found in Germany in the Solnhofen site like Archaeopteryx. The second known specimen was found later in Southern France. Both skeletons are nearly-complete and still-articulated, again like Archaeopteryx, but UN-like it, haven't preserved imprints of skin. Though little-known, Compsognathus may have been the first non-bird dinosaur ever found from an almost-complete skeleton. Even less-known is the fact that some possible small round eggs have been found around the German specimen.

Only 4 ft long and weighing few kilograms, Compsognathus is one of the smallest Stock Dinosaurs, not counting Archaeopteryx, Microraptor (which has to be considered a real stock at this point), and some true extinct birds like the Passenger Pigeon. Like Coelophysis above, its frame was that of a generic small theropod with no sickle-claws on its feet. Compsognathus was more evolved and bird-like than Coelophysis however, with a shorter head and neck, a more compact body, and only three fingers on each hand. Old portraits in popular dino-books have typically depicted the "compy" with two-fingered T. rex-like hands, and sometimes even with fin-like hands: these errors were due to the incompleteness of the two known specimen's hands. More specifically, the German specimen led thinking it was two-fingered, while the French one led the bizarre "finned-hand" hypothesis (said fins turned out to be petrified driftwood). The two-fingered portrait has long been the most common in popular dino-books; the finned one, luckily, has appeared only occasionally. Its slim feet are at the origin of its species name, "longipes" (long foot).

If you hear about Compsognathus in documentary and literary media, it will likely be for two things: its former record of "the smallest dinosaur", classically described as chicken-sized because its first-found German skeleton was only 2 ft long, but was from a subadult — the French specimen was 4 ft long; and its former status as "the closest relative of Archaeopteryx": despite similarities, the compy was possibly less close to birds than tyrannosaurs according to cladistic studies started in The '90s. Another compsognathid, Sinosauropteryx from Early Cretaceous China, shows downy covering around its skeleton but not pennaceous feathers; this was probably the same for Compsognathus, too.

Compsognathus has always been a regular sight in dino-books, in which is usually shown as a solitary hunter of insects, small vertebrates, and sometimes adult archaeopteryges: that last depiction is unlikely though, because Compsognathus was a rather fragile creature to kill a fully-grown "archaeo". It's curious, however, that the tiny Compsognathus could have been the actual top-predator of its insular world devoid of big predatory dinosaurs. Note that the Eustreptospondylus of WWD lived much earlier than Compsognathus in Real Life.

Even though its tiny size doesn't make our Compsognathus particularly menacing for humans, popular media have equally managed to transform it into a "miniature terror". In 1997, The Lost World: Jurassic Park made it a deceptively cute critter which attacks in huge packs. While Compsognathus may have been cute and looking a bit like a long-tailed chicken, there is no indication of social behavior in the two known fossils both found isolated. Furthermore, its thin jaws (the "elegant jaws" that have given to it its genus name) and peg-like teeth were strictly adapted to catch and swallow small prey, and not to tear tough skin like the jaws of other small theropods. The fact that the original German specimen's stomach cavity contained a small lizard (namely, Bavarisaurus) would tend to support this even more. Finally, they are also erroneously classified as Compsognathus triassicus, clearly confusing them with the Triassic dinosaur Procompsognathus, which is actually more closely related to Coelophysis.

1. Entry Time: 1997
2. Trope Maker: The Lost World: Jurassic Park (but already well-known before that for being the "smallest" dinosaur)

Jurassic Coyotes?: Ornitholestes & Coelurus *

Ornitholestes should not to be confused with the similarly-named Ornithomimus. Both were slender animals, but the "lestes" was the same length/size of the Real Life Velociraptor (2m/7ft long and weighing about 15 kgs), while the "mimus" was notably bigger, 3.5m/12ft long about 150 kgs. Like the "mimus", the "lestes" lived alongside many dinosaurs larger and more powerful than it: Allosaurus, Stegosaurus, Apatosaurus, Diplodocus, Brachiosaurus, Camarasaurus, Camptosaurus, Ceratosaurus, the Ornithomimus-sized Dryosaurus (still too big to be its prey when adult), but also with a nigh-identical, only a bit smaller (1.8m/6ft) theropod named Coelurus (not to be confused with Coelophysis) in Late Jurassic North America 150 mya — well before the Late Cretaceous Ornithomimus, but well after the Triassic Coelophysis.

Within their habitat, Ornitholestes and Coelurus arguably played the role of the “small cunning predators”, while Allosaurus and Torvosaurus were the top predators and Ceratosaurus was between the two extremes. Although there is no evidence, they likely ate lizards, mammals, frogs, and insects, and sometimes, also ate the eggs and hatchlings of bigger dinosaurs. In the “Time of the Titans” episode of Walking with Dinosaurs we can see some Ornitholestes behaving in such a way. In many paleo-artistic works Coelurus and Ornitholestes have been shown behaving like jackals, foxes, or coyotes, tearing chunks of flesh from the kills of Allosaurus or Ceratosaurus and fleeing to safety from these larger predators.

Ornitholestes hermanni, the only known species of its genus, was found about 30 years later than Coelurus fragilis ("fragile hollow tail"), which is also the only-known species of its own genus: the latter was found in the Bone Wars by Marsh, and its name was the inspiration for the few-years-later-discovered Cope's Coelophysis bauri ("Baur's hollow form"). Ornitholestes was found at the beginning of the 20th century 20 years after the "Wars": its name, “bird thief”, was given because it was though a specialist predator well-adapted to grasp “first bird” Archaeopteryx with its prehensile hands. Such a thing would not technically be impossible, the two being contemporaries… only, the “proto-bird” lived in Europe, together with Compsognathus. Unfortunately, neither dinosaur is known from very good remains, and it has been historically suggested they were actually the same dinosaur.

In many modern portraits, Ornitholestes (but not Coelurus) used to be shown with a horn-like crest on its nose, seen even in Walking with Dinosaurs; however, we know now that it didn’t have this feature. Coelurus's skull is unknown apart from the thin lower jaw with small teeth. Ornitholestes had a more compact body-build and more robust jaws and teeth than Coelurus; these two Non Identical Twins had arguably less-conspicuous feathers than the dromaeosaurids, more similarly to a "compy".

Walking With also added some speculative erectile quills on the Ornitholestes' neck: though not demonstrated, these might be possible, especially as Ornitholestes has been classified as a bird-like maniraptoran in some analyses, albeit still of uncertain placement within the clade: maybe a distant relative of dromaeosaurids and troodontids. The link with maniraptors is further reinforced by one detail: Ornitholestes had a smallish retractable toe similar to that of deinonychosaurs and early birds, even though almost every work (WWD included) show it with generic bird-like three-toed feet. Coelurus is not known to have had the claw in question (its feet are unknown), and every picture of it shows it with the same kind of feet.

Although overshadowed by larger and more spectacular animals their entire lives, these two dinosaurs did get the last laugh: the coeulorosaur clade (of which they were both members) would go on to fluorish in the Cretaceous period, branching off into the ornithomimids, the maniraptorans (inclluding the dromaeosaurids}, and, of course, the tyrannosaurids. Aside from the abelisaurids (descended from Ceratosaurus and its kin), these were the last major theropods of the Mesazoic era, long outlasting the allosaurid-derived carcharodontosaurs and the megalosaurid-derived spinosaurs (both of which died out in the early-to-mid Cretaceous). And, of course, via birds, they still live today.

Like Coelophysis, some have depicted these two predators as pack hunters, but as one single sure specimen is known for both, this could be unlikely. Other portraits have shown them as among the prey for Allosaurus or Ceratosaurus — though not proven, this is possible, considering that sometimes modern lions, wolves and tigers do feed on smaller carnivores in the wild.

1. Entry Time: 1915 (Ornitholestes); the 2000s (Coelurus)
2. Trope Maker: The artwork of Charles R. Knight (Ornitholestes); Walking with Dinosaurs (the Time of the Titans episode, only the book for Coelurus)

Tyrannosaurs went a LONG Way: Guanlong *

Well, it’s true: the undisputable charm of Tyrannosaurus is also due to the long travel it made to become the King of the Dinosaurs. Tyrannosaurs were already around in the Jurassic, but were still small, inconspicuous animals similar to Ornitholestes. But this is a recent knowledge, confirmed only in the 2000s. The merit belongs to a very undinosaur-sounding dinosaur: Guanlong. Today, Guanlong wucaii may be the most famed dinosaur with “long” (in Chinese means "dragon"; the Chinese word for "dinosaur", "konglong", means "terrible dragon"). The trend to call Chinese dinosaurs with this suffix has started only in the early 2000s; since then “dino-long”s have become more and more common, with at least one new-entry for almost every year — 2021 is a rare exception. This is in part because in China, dinosaurs are always have "long" as their suffix; T. rex for instance is "Bawanglong", meaning "tyrant king dragon".

Easily recognizable thanks to its bizarre backwards-pointing helmet-like crest (which is vaguely similar to the crest of some hadrosaurs, in particular the one of Parasaurolophus), the 10ft/3m long Guanlong lived in the Late Jurassic of China; despite its Coelophysis-like size and body-shape, Guanlong was one of the most ancient tyrannosaurs known back in 2006. Another "dino-long", the surely-feathered Dilong, was found a bit earlier in the famed Liaoning fossil site, was about the same size but lacking any known crest, and lived later, in Early Cretaceous. However, after 2006 Guanlong has lost the record to Proceratosaurus. This was a Middle Jurassic European theropod found at the beginning of the XX century; as its only known remains is a partial skull with a horn on the nose similar to the younger Ceratosaurus (hence its name, "before Ceratosaurus"), it was reclassified as a basal tyrannosaur only in the latest part of 2009. Another basal tyrannosauroid possibly relative of Proceratosaurus was the Late Jurassic Stokesosaurus, known from North American remains since the 1970s. Some thought that Stokesosaurus was the same as the mysterious small theropod Iliosuchus; in turn, the European Juratyrant was long thought to be a species of Stokesosaurus.

But it was too late: the sensationalism which surrounded Guanlong as “The First Tyrannosaur!” soon gave it the general attention in media, to the point that it appeared as the protagonist of Dino Death Trap, a National Geographic documentary appositely dedicated to it: a rare honor for every dinosaur that is not Tyrannosaurus itself. And then, Guanlong was also portrayed in the third movie within the Ice Age series in place of the usual dromaeosaurids. All this can count it as a "rare-stock" dinosaur.

1. Entry Time: 2009
2. Trope Maker: Ice Age: Dawn of the Dinosaurs

At the Start of the Dinosaur Evolution: Herrerasaurus & Staurikosaurus *

Thanks to dino-books and documentaries like those of the Walking with Dinosaurs series, several people have become conscious about the existence of Coelophysis, which has become “the forerunner of the dinosaur world”. However, some carnivorous dinosaurs lived even before it; but are so ancient, that could not even be true theropods. In the Triassic world, dinosaurs were not still not especially differentiated each other, and the familiar “Coelophysis” shape was shared by several other animals, obviously with some degree of variation. Herrerasaurus, Staurikosaurus and Eoraptor are the three most classic examples. Together, the first two form their own dinosaur subgroup, the Herrerasaurians, whose namesake Herrerasaurus is the official archetype.

Their shape was typically theropodian, but the skeleton was much more archaic and less bird-like than Coelophysis; both Herrerasaurus and Staurikosaurus had five digits in their feet, more similarly to sauropodomorphs like Apatosaurus or Plateosaurus than to neotheropods ^note lit. "new theropods", this is the technical name for theropods more evolved than herrerasaurians, when the latter are considered true members of the lineage, which have only four like most modern birds as well — birds never have more than four toes in their feet, unlike mammals. Also, their pelvises were unique, with mixed traits of both theropods and sauropods. This bony-puzzle caused many headaches among paleotaxonomists: Staurikosaurus and Herrerasaurus, indeed, have been variably classified as true theropods, true sauropod-relatives, generic primitive saurischians, the only dinosaurs neither-saurischians nor-ornithischians, and in the most extreme case, even non-dinosaurs at all!

Herrerasaurus was discovered in the 1960s in what is now Argentina. It was a bit longer than a Coelophysis (3-4 m) but much more robust, with a larger, stronger head and shorter neck, almost-recalling more a miniature "carnosaur" than a "coelurosaur" (in the former senses of these words). Herrerasaurus was arguably a more powerful predator, hunting relatively larger animals than those hunted by Coelophysis: possible prey for it could have been the beaked rhynchosaurs, mammal-ancestors, and small-sized dinosaur-relatives like Pisanosaurus. But Herrerasaurus was still small compared with other early carnivorous dinosaurs like Dilophosaurus or Cryolophosaurus, and arguably retreated against the 7 m-long carnivorous dinosaur-relative Saurosuchus, the true apex predator of its time. Some Herrerasaurus remains were originally put in their own genera, "Frenguellisaurus" and "Ischisaurus", but both are not considered the same as old "Herrera". Herrerasaurus was found in Ischigualasto, the formation in Argentina in which it and other dinosaurs & non-dinosaurs have been found — the complete name of this dinosaur is indeed Herrerasaurus ischigualastensis.

Discovered in 1970 slightly after Herrerasaurus, Staurikosaurus shared the same body-structure of the latter (with some differences) but unlike Herrerasaurus was smaller than Coelophysis, only the size of the real-life Velociraptor: 2 m (6 ft) long. It arguably hunted smaller prey, perhaps young rhynchosaurs or smaller mammal-ancestors. Staurikosaurus was originally put in its own family, the Staurikosaurids (Herrerasaurus was put in the Herrerasaurids); primitive traits shared both including the presence only two vertebrae in their sacrum (like modern reptiles), not four or five like typical dinosaurs and birds.

Staurikosaurus is also one of the most poetically named dinosaurs, “Southern Cross lizard”: it could be renamed the "Starry Dinosaur" for this. It has been for several decades the only dinosaur found in Brazil, and the Brazilian flag shows just this constellation. However, the staurikosaur was found in the southernmost part of Brazil, just near the boundary with Argentina. Its complete name is Staurikosaurus pricei; one alleged relative, "Teyuwasu", has recently been reclassified in its genus.

Together, Staurikosaurus and Herrerasaurus have long disputed the title of “the first/most primitive dinosaur ever appeared on Earth”, with some books preferring one and others preferring the other. Anyway, among the numerous hypotheses made in the 80s, some paleontologists went to claim herrerasaurians were the ancestors of all the other dinosaurs: now this hypothesis is totally discarded, since they had their specializations on their own, included some evolved traits, ex the complex shape of their pelvis. Monotremes (platypus & echidnas) are the most primitive mammals today, but this doesn't mean they are the ancestor of marsupials and placental mammals after all, and they too have specialized traits (horny beaks, electric sensors, or even venom-spurs in the case of the platypus) that lack in the other living mammals.

1. Entry Time: undetermined
2. Trope Maker: their former status as "the First Dinosaurs"

Other small theropods or theropod-like dinosaurs

Sorry, these ones aren't here. If you're looking for Scipionyx, Noasaurus, Masiakasaurus, Elaphrosaurus, Proceratosaurus, Procompsognathus, Megapnosaurus, Sciurumimus, Juravenator, Saltopus, "Protoavis", and others, see here.

Historically-Extinct Birds

As easy as it is to forget, birds are dinosaurs as well. Specifically, birds are members of the maniraptoran clade, which also includes the aforementioned dromaeosaurs, troodontids and oviraptorosaurs. Yes, that means that dinosaurs are technically not extinct! These contain the only Cenozoic dinosaurs on this list.

The Symbol of the Extinction: the Dodo ***

One of the most recently extinct stock dinosaurs (in a technical sense, anyway), having been wiped out before 1700 in the Modern Age, the dodo (scientific name: Raphus cucullatus) was a turkey-sized flightless pigeon that lived on the small isolated island of Mauritius, east of Madagascar. The pigeons it was descended from almost certainly flew to the island, but because there were no land predators, the dodo evolved secondary flightlessness, no longer needing the luxury of flight — which may have been an evolutionary mistake, considering what happened when humans and their pets showed up. Its diet was likely comprised of fruit and seeds, as well as possibly insects.

The circumstances of the dodo's extinction are commonly misinterpreted. The most common explanation was that they were simply unable to comprehend that humans were NOT friendly and thus were hunted for their meat until they all died out. In reality, it wasn't that simple. While they were hunted for a time and it is likely that these birds were a little too brave for their own good (many modern birds on Mauritius still can't take the hint), they certainly weren't helpless creatures — their beaks were very large, sharp and uncinated like a bird of prey, and reportedly were capable of delivering painful nips if the dodos got agitated. Additionally, the meat of the dodo was said to have been very tough and oily, making it very unpalatable for human consumption. It is now thought that the demise of the dodo came along because of a mix of the invasive species brought into the island and the destruction of their habitats by humans looking to take up residence on the island. A mixture of the hunting, invasive species and habitat loss ultimately dwindled down the poor birds' numbers until there were none left. As with all extinctions, it was a number of factors that led to their demise, not quite as simple as "we ate them too much"... though ultimately, the common denominator was still always humans.

Dodos are frequently thought of as having been stupid creatures, to the point that we have a trope for this portrayal and a proposed origin for its name was a Dutch word meaning "simpleton". We now know that dodos were no more or less intelligent than any other pigeon and that because it was a pigeon, and not an odd chicken/turkey as often believed, a more likely origin for its name was the sound it made, which most likely sounded like a soft "doo-doo".

The dodo had a cousin on a neighboring island called the Rodrigues solitaire — which sadly also went extinct — and its closest living relative is the Nicobar pigeon. Other extinct birds from the Mascarene islands (Mauritius, Reunion, Rodrigues etc.) included a giant ground-dwelling parrot, a harrier, a sparrowhawk-like owl, a sundry assortment of flightless rails, and even a flightless ibis, the latest one was once believed a dodo relative, the "Reunion solitaire". Together the dodo and the two solitaires, the real and the ibis one (note that "solitaire" = "lonely" in French) used to make their own family of birds, the Raphids: modern taxonomy put the dodo and Rodrigues' solitaire in the same family of all the other living or extinct pigeons/doves, the Columbids.

The dodo is probably the most famous extinct animal that didn't come from the Mesozoic or the Pleistocene Ice Age. It comes from Modern History, to the point that a notable euphemism for death or obsolescence is "going the way of the dodo" or "as dead as a dodo". On a more serious note, the dodo's extinction is one of the things that has motivated humankind to try and be more environmentally minded — after all, we were able to drive this innocent, goofy-looking bird to extinction, who's to say we won't end up wiping out more species? Sadly, not everyone got the hint, not to mention we lost many species before the dodo too, for example the giant Moas from New Zealand and the Elephant Bird from Madagascar (see below).

The dodo's fame probably started with Alice's Adventures in Wonderland, when an anthropomorphic dodo appears among the animals Alice encounters in Wonderland. The Dodo in the book is said to be an Author Avatar for Lewis Carroll. Dodos have appeared all over the media, usually depicted in the outdated "fat, stupid waddling birds" portrayal, as opposed to the thinner and more bold birds that we know they were now. They'll often be put into a post-dinosaur world for comic relief — for example, in Ice Age where the dodos are depicted as possessing almost suicidal stupidity. Most media will also forget that the dodo is a pigeon. Regardless, the dodo will almost never be depicted as a Prehistoric Monster, unless it's mutated or something, and even then it will be seen as a joke rather than a threat, as was the case in Primeval (where the real threat was a dodo parasite that jumped to humans).

1. Entry Time: 1865
2. Trope Maker: Alice's Adventures in Wonderland

The Penguin of the North: the Great Auk *

Here's another recently-extinct bird that is rather common in popular paleo-sources, though less in more mainstream media. The Great Auk's scientific name is Pinguinus impennis ("featherless penguin", even though it was feathered!).^note Interestingly, true penguins were once also scientifically called impennes, "featherless", but they too are feathered despite the smallness of their scale-like wing-feathers. This is not a mere coincidence however: indeed, the word "penguin" originally just indicated this bird, which people used to see in the Northern Atlantic coastlines before the spheniscids (aka the commonly-intended "penguins") were actually discovered in the 16th century, during the first explorations of the Southern Seas. In other words, Polar Bears and Penguins was once Truth in Television.

The Great Auk was a relative of modern puffins, murres, and razorbills: that is, it was a member of the Alcids, the "Auk family", and was also related more distantly to seagulls, terns, woodcocks, plovers, curlews, jaegers, and so on (all of them belong to the bird-group named Charadriiformes). It resembled a modernly-intended penguin because of its erect pose, black & white plumage, and palmated feet, but mainly because it was flightless unlike the modern auks, all fliers. The great auk had very reduced wings, unapt for flight but apt to swim underwater — its swimming style is uncertain: it probably used both the wings and the feet, unlike true penguins which mainly use their wings. The great auk had a characteristic black bill, with parallel keratinous crests on the base of it — modern auks also often have striking beaks, especially the puffins with their large colored bills (they are called or nicknamed "sea-clowns" in some languages just thanks to this). The extinct auk was large, too: 3 feet tall and weighing several kilograms, much more than still-living auks, about the size and weight of a King Penguin, but still smaller than an Emperor Penguin (the biggest living spheniscid) or the Mesozoic toothed Hesperornis.

Sadly, this large specialized seabird was depleted by us humans during the 19th century thanks to overhunting: the last two specimens were killed in year 1844, two centuries later than the tropical island-dweller dodo. Indeed, all around the world, flightless birds have revealed to be the most vulnerable to extinction, especially those living in insular worlds — not only dodos, elephant birds, and moas, but also less-familiar groups like the dodo-like Moa-Nalo ducks in Hawaii. The flightless or poorly-flying Takahe and Weka rails, the Kakapo parrot, the Kokako songbird, all of New Zealand, the Laysan duck of Hawaii, and still other similar birds around the world managed luckily to escape this fate Just in Time, but many are still endangered. Like the dodo, it was said that the auk used not to show fear toward its human hunters.

Unlike other historically extinct animals like the iconic Dodo and the cattle- and horse- ancestors Aurochs and Tarpan (painting in caves and ancient literature), the Great Auk is mentioned mainly in modern scientific or educational works, which is odd, considering its cute, penguin-like appearance. The auk's only notable appearances in fiction were in Charles Kingsley's novel The Water-Babies, where one tells the tale of the extinction of its species, as well as in Assassin's Creed Rogue where flocks of them can be seen in the 18th century Arctic Circle.

1. Entry Time: 1863
2. Trope Maker: The Water-Babies

The most common Bird before Extinction?: the Passenger Pigeon *

This small bird, together with the following one, is surely the least striking among the extinct birds listed here, but is famous because of the story that led it to its disappearance in the end of the 19th century.

The passenger pigeon (Ectopistes migratorius), unlike the dodo, was a totally normal-looking pigeon (pigeons and doves make together the order Columbiformes) that used to fly in huge flocks across North America. Before its demise it was one of the most common birds here, with millions of specimens that, it was said, "obscured the sky when flying in group" almost like a living cloud. Some even declare that the pigeon was once the most abundant bird in North America or even in the whole world, but this is not demonstrable. Among the most abundant still-living wild birds there are some species of weavers (small songbirds of the Ploceid family, not pigeons) that live in African savannah, ex. the red-billed quelea (Quelea quelea) and the southern red bishop (Euplectes orix). Also, some petrels (small seabirds similar to the albatrosses) are very abundant today, ex. Wilson's storm petrel (Oceanites oceanicus).

The passenger's appearance and size were those of a typical wild pigeon, with bluish-gray and brown feathers, and emitted sounds very similar to those of most pigeons & doves. While one could assume that it was a very popular game among hunters and nest raiders, and its extinction was not due to insularism and flightlessness. The Passenger Pigeon was however an ecologically very strict bird, which lived only in specific niches, thus more vulnerable to overhunting than other less-common but more adaptable birds of the USA like wild turkeys or bald eagles. The only passenger pigeons you'll see nowadays are preserved specimens in museum exhibits, science archives, and the like. The very last passenger pigeon, named Martha, lived in the Cincinnati Zoo, where she died in 1914.

In fiction, this bird is very unlikely to appear because of its generic dove-like look. Indeed, it is notable mainly for its absence from popular American period pieces set during the time it was abundant. When it's mentioned in fiction, it's always in the context of its extinction.

1. Entry Time: undetermined
2. Trope Maker: Cultural fallout from its extinction

Extinct Parrot: the Carolina Parakeet *

Another extinct bird that inhabited the USA since about a century ago was the small Carolina Parakeet (Conuropsis carolinensis). One of only two parrots living historically in the United States (the other is the bigger and now-endangered Thick-billed parrot, once present in south-western USA but now limited only to Mexico), the Carolina parakeet was a small parrot with a long tail, a medium-sized beak, and an overall green plumage but with an orange-yellow head. Like the more known Passenger Pigeon, the parakeet was an ecologically-strict species of flying land-bird that was very abundant once — some say even more numerous than the passenger pigeon itself in certain places, but it too was destroyed by overhunting. Like the pigeon, the parakeet was often accused to destroy crops when too numerous, like what happens today to several extant passerine birds (crows, magpies, jays, sparrows, finches, weavers, starlings, etc., which are however more ecologically flexible). Like the passenger pigeon, the very last individual lived at the Cincinnati Zoo. Named Incas, he died in 1918, a year after his mate Lady Jane died. Coincidentally, Incas was housed in the same enclosure that formerly held Martha the passenger pigeon.

Like still-living parrots (but also cuckoos, roadrunners, toucans and woodpeckers) and unlike pigeons and songbirds which have the typical theropod foot with three foretoes and one hindtoe, the Carolina parakeet had unusually two anterior toes coupled with two posterior toes on each foot: the so-called "zygodactyl foot" that allows to grasp well the branches of a tree (and to manipulate tools in the case of the parrots). The Carolina Parakeet was arguably a very intelligent bird like modern parrots, and very likely could be kept as a pet and be a human-voice imitator if alive today. Like the pigeon, is very unlikely for it to appear in fiction because of its normal-parakeet look — in fact, it was almost identical to the Jenday parakeet of South America.

1. Entry Time: undetermined
2. Trope Maker: Cultural fallout from its extinction

Giraffe-Bird: the Giant Moa **

Giant dinosaurs were not exclusively a prehistoric-only affair: two really large birds have lived in historical times: the Moa and the Elephant Bird.

Both were Ratites, aka flightless birds related to ostriches, rheas, cassowaries, emus, and kiwis. Moas (a Maori word meaning "fowl"), also called Dinornithines from their best-known genus, Dinornis ("terrible bird"), lived in New Zealand like the more popular icon of this country, the kiwi. The biggest moas, obviously, are the most shown in media, especially Dinornis maximus (maximus = "the biggest"), now split in two species, D. robustus of the Southern Island and D. novaezealandiae of the Northern Island. Others, though, were fairly smaller, like Emeus crassus, lit. "fat emu", or Anomalopteryx, lit. "strange wing". The latter one was no bigger than a turkey. The Giant Moas reached 3.5m /12ft in height, much taller than the tallest living ostrich (9 ft at the most), and were also more heavily-built, with stocky legs and a massive body: they could have weighed 250 kg or more - ostriches at the most weigh 150 kg.

According to semi-fossilized remains, moas' plumage was rather similar to a kiwi's in texture and color, and like the latter they had no visible tail. They reduced their wings to an extreme, even more than the kiwi itself ^note the latter's scientific name, Apteryx, means wingless, but it has a small remnant of wings hidden by the body-plumage.: moas were totally devoid of them, even in their skeleton (except for the remnants of shoulder-girdle and humeri), making them the most extreme known case of reduction of the anterior limbs among theropods, together with the Mesozoic hesperornithines.

Giant moas were by far the biggest New Zealand animals of their time: they had small heads and bills, long giraffe-like necks, three-toed feet, and were probably more strictly herbivorous than modern large running birds (ostrich, emu, rhea, cassowary), which also eat insects or small invertebrates other than plant matter. Moas had no potential predators that could have killed them, except for two: the Haast's Eagle which preyed upon smaller species & the juveniles of the biggest ones (and maybe sometimes even the adults of the latter, see below), and more importantly, humans. The ancestors of the Maoris first colonized the distant New Zealand archipelago during the European Middle Ages, probably heavily hunted them, and/or gathered their eggs, or set fires, unwillingly eliminating the few still-living dinornithan species. Since today, Maoris have told stories and legends about these birds their ancestors had the fortune to see in life.

Kiwis (five species, family Apterygidae) managed to survive, but then, European colonizers reached the islands introducing several household mammals in the wild like cats, rats, pigs, dogs, weasels etc., which almost managed to deplete the animal they later chose as their national symbol.

In modern pop-culture, the giant moa is associated with the so-called "terror-birds" because of its size and shape, even though it has never been depicted as a voracious predator unlike the Diatryma (Gastornis) or the Phorusrhacids, but usually as a Gentle Giant, because of its smaller head and round bill and its more overall inoffensive look. Moas are virtually guaranteed to show up in works involving ancient New Zealand, and, for Rule of Cool reasons, the giant moa is by far the most frequently depicted one.

1. Entry Time: undetermined
2. Trope Maker: Its size and Maori legends

Huge Eggs: the Elephant Bird *

The Elephant Birds have a particularly apt name. They are more properly called Aepyornithines — the latter name meaning "lofty bird": the two most portrayed species are, again, the biggest ones, Aepyornis maximus & Aepyornis titan (renamed Vorombe titan, in the late 2010s, but then synonymized with A. maximus after DNA studies revealed they were just exceptionally large females of the species). A third aepyornithine, Mullerornis modestus, was fairly smaller and slenderer than A. maximus.

Elephant birds lived in Madagascar, the large island of the Southern Hemisphere close to Africa whose most famous animals are the lemurs — incidentally, not far away from the much smaller Mauritius, the former home of the equally extinct but much smaller dodos. These Malagasy birds shared with moas a similar outward appearance but their skeleton was rather different. The two kinds of "giants of the southern islands" were not strictly related to each other, but both shared the same similarly-reduced "wings", even though the wings of the aepyornithines were less-reduced.

Elephant birds, however, were even more massively built than the giant moas, with a huge body and very stocky "elephant-like" legs — hence their common name. The biggest ones were maybe the largest/heaviest birds of every time, but still shorter than giant moas because of their shorter neck. They resembled a bit overgrown emus or cassowaries, with massive bodies and three-toed feet — while dinornithines, being slenderer, looked more like true ostriches but with the plumage of a kiwi. Both dinornithes and aepyornithes possibly behaved the same way, and the latter were probably mainly herbivorous as well. Despite their bulk, elephant birds were arguably able to run, like how modern elephants that can run at 40 km per hour (faster than a human).

During the first explorations of the Malagasy island made by European navigators after the 17th century, they found the fragments of some truly gigantic eggshells, belonging to eggs twice the diameter of the biggest modern eggs (those of the ostrich, that are about one foot of diameter), and still today the biggest known eggs of any land animal known.^note The biggest known non-bird dinosaur eggs are, astonishingly, only the size of those of the modern ostrich, no more! Later, other semi-fossilized remains were found of aepyornithines, the biggest of them revealed being among the heaviest birds ever, if not the very heaviest: maybe more than 540 kg, like a small cow. Only the biggest dromornithines (another group of extinct flightless birds, this time from Australia) could have rivalled them in mass. The Elephant Bird gives its name to one of H. G. Wells's tales: The Aepyornis Island, published in 1894.

The extinction of the "elephant bird" is still unclear: it was the biggest land animal of Madagascar before its extinction (bigger even than the giant lemurs of the time), and with the possible exception of crocodiles, it didn't have any natural predators. There are different hypotheses about the real cause of their demise. Hunting? Introduction of foreign species? Egg gathering? Even the precise period of their disappearance is uncertain. Today, the extant land animals of both Madagascar and New Zealand are much smaller than these giant ground birds, being below 10 kg of weight (extant lemurs and kiwis weigh few kilos at the most).

Some have speculated that the mythical Roc Bird was inspired from ancient Arab sailors who saw these birds alive in Madagascar in the Middle Ages. This is controversial though, since the Roc, unlike the elephant birds, used to be portrayed like a giant flying bird of prey. It's speculated that aepyornithines were mistaken for baby Rocs, with the also extinct Malagasy crowned eagle perhaps being (by misjudging their size and distance in the air) mistaken for the adults Rocs. A truly prehistoric bird that actually resembled the roc in shape and size is Argentavis, the "Argentinian Bird", living about 8 mya, but we'll get to that critter later.

1. Entry Time: 1894
2. Trope Maker: Its size and its possible relation to the Roc myth

Kidnapping Bird of Prey: the Haast's Eagle *

Traditionally, this bird was called "Harpagornis", meaning "grappling-hook bird", but it has recently been put in the still-living raptor genus Hieraaetus, which includes some species of modern eagles. Living in New Zealand at the same time as the moas, the Haast's eagle is the largest known eagle that ever lived. Ironically, it was closely related to the little eagle of Australia, a bird less than a third its size. The Haast's eagle itself, however, had a wingspan of up to 2.7m/9ft, and could weigh as much as 15 kg/33 lbs. The Haast's eagle's talons, nonetheless, were as large as the claws of a grizzly bear, and it was perfectly capable of killing a fully-grown giant moa— a bird fifteen times its size, even though the eagle arguably hunted more often the smaller moa species or the young of the giant ones. With no predatory mammals in New Zealand, the Haast's eagle was the apex predator, the only eagle ever to have this distinction.

The Haast's eagle became extinct along with the moas sometime in the 1400s, but it was incorporated into Maori folklore as the Pouakai, a monstrous bird vaguely similar to the Roc of the Middle East. In many Maori tales, Pouakai kill humans, which, given that the Haast's eagle was capable of felling an adult moa, seems entirely possible. It is possible that the eagle's extinction was caused not only by its prey being hunted, but also by deliberate persecution from the ancestors of the Maori, who might have seen it as a threat or a source of eggs and feathers.

Popular depictions of the Haast's eagle often portray it as simply a scaled-up version of a "typical" eagle, but this was not the case. Its wings were relatively short for its size, allowing it to easily fly in dense forests, more like a small forest hawk like the sparrowhawk or the bigger harpy eagle of the Amazon Forest than to a "classic" eagle like the golden eagle or the bald eagle. Its feet were also disproportionately large (again like the harpy eagle), with massive talons for gripping its oversized prey. Its head, meanwhile, was long and narrow. The first scientists to discover its remains thought this meant it was a scavenger, since it resembled the skull of a vulture, but it's now believed this was an adaptation to rooting inside the bodies of freshly killed moas.

Despite its appeal, the Haast's eagle has been a relatively rare sight outside of documentaries. Its first notable appearance in a documentary was in Sir David Attenborough's The Life of Birds, where it is live-acted (not very convincingly) by a Harris's hawk and shown hunting a CGI moa. It has since appeared in Monsters We Met (live-acted by a harpy eagle) and a number of other documentaries on prehistoric New Zealand, and even in Jurassic World: The Game.

1. Entry Time: 1998
2. Trope Maker: The Life of Birds

Prehistoric Birds

These birds are often confused or mixed up with the historically-extinct birds above. Some of them were strictly related with the modern feathered vertebrates (ex. Gastornis, Phorusrhacos, Argentavis); others were more a middle-way between non-bird theropods and modern birds (Archaeopteryx, Ichthyornis, Hesperornis). The latter lived during the Dinosaur Age and were Toothy Bird; the former lived across the Mammal Age and were similar to modern birds in anatomy, but bigger than most modern birds.

The Symbol of the Evolution: Archaeopteryx ***

Archaeopteryx lithographica ^note OK, depending on who you ask, it might actually be a non-bird dinosaur, but we're putting it here anyway. lived around 150-148 mya in Late Jurassic Europe. The name Archaeopteryx means "ancient wing" or "ancient feather"; another obsolete synonym very common in old textbooks was Archaeornis, "ancient bird". Both terms are very meaningful about its historical relevance. lithographica means "from the lithographic (stone)" because the flat rocks it was found in were used in the past as tables for writing. And it is even sometimes known as the "Urvogel", which is German for "original bird" — it's rare that a dinosaur receive a common name that is not a mere translation of the scientific one, unlike Ice Age critters.

Archaeopteryx was discovered in 1861 in the famed Solnhofen deposit in Germany, whose rocks have preserved fossils so well that even soft parts of animals are visible. Because of this, most specimens of Archaeopteryx found later in Germany (about 6-7) were found with impressions of feathers.

Charles Darwin had published On the Origin of Species two years earlier of the finding of the first "archie" fossil, and in the following debate, this "half-reptile, half-bird" became a key piece of evidence, as the ultimate example of a "missing link" between two animal classes. Other examples were found later by scientists throughout the 20th century: Ichthyostega (fish-amphibians), Seymouria (amphibians-reptiles), Cynognathus (reptiles-mammals), and several others, see Stock Dinosaurs (Non-Dinosaurs) and Prehistoric Life.

A century after the first description, Archaeopteryx was again used as crucial evidence, this time in John Ostrom's theory that modern birds had evolved within the theropod group. Before that, most scientists considered Archaeopteryx and its bird-descendants only distant relatives of dinosaurs, in part because in traditional zoology Feathers = Bird, and no other dinosaur was known with imprints of feathers. Even though one scientist (Darwin's pupil T.H. Huxley) already recognized the dinosaurian origins of birds as early as the late 19th century by studying the skeletal features, this was largely accepted only after the Dinosaur Renaissance. American Ostrom, who named and described Deinonychus, and German paleonologist Peter Wellnhofer, the main Archaeopteryx expert, noted the strong analogies between the respective animals' skeletons, especially their forelimbs. The link was definitively proven only in the 1990s after the find of the feathered "Liaoning theropods".

Archaeopteryx has had a somewhat unique role among stock prehistoric animals: just like the Dodo is the icon of Extinction, Archaeopteryx has been that of Evolution. Within the long-lasting debate between scientists and creationists, the latter have gone so far to claim Archaeopteryx fossils are just fake.

According to modern knowledge Archaeopteryx is just another feathered theropod — possibly a bird, possibly a deinonychosaur, possibly more primitive than either. Highlighting its theropodian nature, one archaeopterygid skeleton with no signs of feathers was long classified in another theropod genus: Compsognathus, believed scaly like every other nonbird dino until few decades ago. The size of a chicken, Archaeopteryx had a long bony tail (modern birds always have stubby tails), three claws on its forelimbs, running feet with an enlarged second toe claw (this was discovered only in the 2000s), jaws with small, pointed teeth, and feathers. The main difference is that its feathers aren't just skin-covering down; it has flight feathers of very modern-looking shape on its wings and tail. It could probably glide, but it is unlikely that it could flap its wings for powerful flight — it didn't have the modern birds' keeled breastbone for strong wing muscle attachment, but the usual "ventral ribs" seen in non-bird theropods.

Maybe it simply used its claws to climb up trees and then glided to the next tree like a "flying squirrel" or a "flying lemur", maybe it could make true short moments of active flight, but with little endurance. There are a bunch of modern reptiles behaving in a similar way of the traditional depiction of the "gliding Archaeopteryx": the "flying dragon", the "flying snake", and the "flying gecko", all from Southeast Asia. And then, the amphibian "flying tree frog", also of Southeast Asia, and even the oceanic "flying fish". The Archaeopteryx's diet probably consisted only of insects and small vertebrates, but no stomach contents are known; We also know what color it was in life — it's often classically depicted with blue plumage with shades of yellow, like a blue-and-yellow macaw (Ara ararauna), while its neighbor Compsognathus is often greenish in paleo-art, but thanks to analyses of some exquisitely preserved pigments, we now know "archie" was black and white like a magpie.

Its classic status as "the first bird" is merely traditional at this point, and the start of the "bird lineage" within the theropod branch depends on the chosen criteria to define what’s a bird and the "archie"'s exact position in the evolutive tree. Still, it remains one of the most ancient known dinosaurs found with imprints of feathers, one of the very rare ones from the Jurassic (most of the others, like Microraptor or Sinosauropteryx, were Cretaceous).

In media, Archaeopteryx is well-established as the "first bird". It will sing like a bird and perch like a bird, neither of which was possible for the real-life Archaeopteryx; expect it to fly in the same manner of a modern bird too, though recent studies showed that, though it could actively fly, it likely wasn't very good at it and only did so in times of emergency or when it was convenient — these studies revealed that its flight patterns would've been fairly similar to a modern pheasant or quail, known for be mostly ground-dwelling birds. Media archeopteryges will lack the sickle claws on their feet, and occasionally also their wing-fingers and teeth, making them looking like full modern birds (see the cartoon Dinosaucers for an example of toothless, fingerless archaeopteryx). But, contrastly, expect also to see them with naked heads in dino-books, making them resemble feathered lizards. Actually, their heads would have been almost totally feathered like deinonychosaurs and most modern birds, see Raptor Attack.

Strangely, despite its iconic status, Archaeopteryx has yet to appear in CGI docs: Walking with Dinosaurs misses completely it, despite the fact that its world, Late Jurassic European small islets, is shown in Cruel Sea. Even the franchise Jurassic Park never mentions it. To compensate, it shows up in Fantasia, and in other fictional works, but usually as a simple ambient-animal with minor roles.

1. Entry Time: 1861
2. Trope Maker: Darwin's On the Origin of Species

Dinosaurs continued to Rule: Gastornis or "Diatryma" **

Long-standing paleo-fans will remember the name "Diatryma" for sure: that large, flightless, large-headed predatory bird who used to hunt the small "horse" Eohippus in so many paleo-artistic depictions placed in Eocene North America. Well, now poor "Diatryma" seems having definitively disappeared... but luckily, it hasn't, as such: it's simply changed identity. Now we have to call it Gastornis (a far less awesome name, we've got to admit, but... never mind). Whatever name should be used, this has always been one of the most enigmatic extinct animals of all.

Since its discovery in the 19th century made by Edward Cope in the USA, scientists have debated if Diatryma was a carnivore, an omnivore, or an herbivore. The predatory view ultimately won the context for more than a century, but as recently as in The New '10s it was shown by experts that it wasn't probably carnivorous at all. The problem is, its beak was strong but not hooked like an eagle's, its body frame was stocky, seemingly slow-moving, like an elephant bird, and its claws lacked killing adaptations. And to top it off, isotopic analyses of its bones matched those of herbivores. Thus, it probably was a vegetarian that used its bill to crack nuts and cut vegetation, making erroneous the Bizarro Universe portrayal in Walking with Dinosaurs and the whole paleo-artistic tradition, where these birds are shown ruling mammals of every kind (and not only the "ur-horse" Eohippus). In the show, the bird's size is also exaggerated (it did not weigh half a ton as said, but only a bit more than an adult person).

However, this does not mean automatically the diatryma/gastornis was the Gentle Giant news articles claimed it was. Ostriches, emus and cassowaries are mainly herbivores too, but they're also some of the few birds that have been known to kill people for self-defense — ostriches and cassowaries have even one enlarged claw in their foot, like a dromaeosaur. Gastornis hadn't such weapon, but not only grew to their size, but it also had a much more powerful beak that would've been useful for fighting off the land-dwelling crocodiles like Boverisuchus or the giant constrictor snakes, that were the true dominant predators of the early Cenozoic. Regardless, Gastornis was definitely a literal and figurative giant in its forested world ^note Sometimes wrongly shown living in prairies, which actually appeared 20 million years later in the world, and so didn't exist yet at the diatryma's times., 40 million years ago: while mammals were still mostly small, except for some pantodonts and mesonychians, some birds grew to large size. Regardless, the new plant-eating image of Gastornis hasn't really caught on in popular media, and you'll still hear folks mentioning it as the horse-hunting killer it was once perceived as.

In several depictions (Walking With Beasts included), Gastornis/Diatryma is shown with a wrongly uncinated beak and naked skin-colored face or even neck, making it similar to an ostrich/turkey or a vulture... underlining both its flightlessness and its alleged carnivory and fierceness; actually, the texture of its plumage and its overall coloration are totally unknown, since soft tissues have not been found yet. You might also see it wingless in illustrations, while its skeleton shows small wings possibly covered with feathers and visible externally, but useless for flying like those of the Dodo or the Great Auk.

1. Entry Time: start of the 20th century
2. Trope Maker: The paintings of Charles R. Knight; Walking with Beasts popularized the new name Gastornis

The true "Terror Birds": Phorusrhacos & Titanis *

With the Phorusrhacids (popularly known as "terror birds"), on the other hand, we did never have doubts this time: thanks to their light weight and slender running legs, they surely were active hunters of small to mid-sized mammals. And with their strongly hooked, very eagle-like bills, they probably did not always swallow their prey whole. Because of their beak, great size (the biggest stood 10 feet tall), and flightlessness, they could also be renamed "the Giant Running Eagles".

The prototypical terror bird was South American Phorusrhacos (often misspelled "Phororhacos", "Phororhacus", "Phororachus", and similar) lived in the Miocene about together with the "roc" Argentavis and the sabertoothed marsupial relative Thylacosmilus, before hominids and true sabertoothed cats appeared. The North American Titanis walleri (lit. "the Waller's titanic one") lived in in the Pliocene in the southern United States, having entered the continent following the formation from the Isthmus of Panama around 5 million years ago, where it competed with wolves and sabertooth cats for prey. Despite the chronological and geographical differences, its not uncommon for the two to get mixed up with one another, such as in Walking with Beasts, which depicts Phorusrhacos as living alongside Pleistocene megafauna and justifies by claiming Titanis is the same animal (a theory that had been proposed at the time, but was never accepted widely).

Phorusrhacos and Titanis are the two most portrayed species of the family: among the others, Kelenken was found only recently in Argentina, in 2007, but is now the largest known phorusrhacid. It lived earlier than Titanis, about the same time of Phorusrhacos. Other less-known members were less-tall but more robustly-built than them, ex. Brontornis, "thunder bird". There were also lots of small species of terror birds, some no higher than 3 feet; none of them get a lot of attention though when compared to their much more massive relatives.

Despite being only distant relatives, and the aforementioned Science Marches On, expect Gastornis to be lumped in or confused with them anyway. In fact, Gastornis was actually more closely related to ducks and chickens than to the Phorusrhacids, which in turn are part of the modern order Cariamiformes, which today consists solely of the seriema, a small bird from South America that's basically a miniaturized terror bird in a lot of ways. Once, both of these ancient kinds of ground birds were classified in the artificial Gruiforms assemblage, which included cranes, rails, bustards, seriemas, and buttonquails among the others. They were also put in their own orders, Diatrymiforms and Phorusrhaciforms respectively, by some in the past. The not-related African secretarybird (Sagittarius serpentarius) is similar to the terror birds as well, but is actually a true bird of prey related with eagles and hawks.

They were once thought to have a one clawed finger protruding from each of their tiny wings, for uncertain purpose. This is not as strange as one may think: there are also living birds with this feature, the most notable being the two-fingered young Hoatzin of South America. However, it was later discovered that their living relative, the seriemas, have similarly-shaped wings and lacks wing claws, making these fingers unlikely.

Terror birds are a staple of paleo-books and documentaries featuring Cenozoic life. They are portrayed as underdogs of the sabertoothed cats that entered South America during the Pliocene, as seen in Prehistoric Park and Walking with Beasts. In reality, phorusrhacids were probably powerful enough to fight off a Smilodon from their carcasses; it's just that smilodonts are usually believed "superior" to terror-birds only because they're mammals like us, but also because they survived longer in South America than the birds, even though both kinds of predators lived together in Pleistocenic North America before we humans appeared. However, only the sabertooths survived until the arrival of humans in the New World; the last terror birds became extinct a mere 2 million years ago (terror bird fossils purported to be from the time humans arrived in the Americas have all turned out to be misdated).

The most notable appearance of the terror birds in non-documentary fiction is in 10,000 BC, where they fill the role that raptors would in most other media. Never mind that terror birds were already extinct by the time humans showed and most certainly did not ever make it to the Old World as the film implies. However, they do have a history of pop culture appearances prior, such as Ray Harryhausen's Mysterious Island and Sir Arthur Conan Doyle's The Lost World (1912).

1. Entry Time: 1912
2. Trope Maker: The Lost World (novel) for Phorusrhacos, and its status as the "North American terror bird" for Titanis

Toothy Diving Bird: Hesperornis *

Hesperornis ("western bird") and Ichthyornis ("fish bird") have traditionally been the two most commonly depicted Mesozoic birds in books (not counting the superfamous "missing link" Archaeopteryx of course), both from Late Cretaceous North America, unlike the latter, which was Late Jurassic and European.

Both were discovered during the Bone Wars by Othniel Marsh. Since Hesperornis is cooler, here we'll mention it first. Hesperornis, whose original species is called regalis, "royal" in Latin, lived in the same habitat in which pteranodonts, tylosaurs, elasmosaurs and archelons roamed: the shallow inland sea which used to cover the American Midwest at that time, dividing North America in two parallel strips of land running from the Arctic down to the south. Despite living in such an early period, Hesperornis was already a very derived bird. 6 ft long (the size of a human, taller than an Emperor penguin and much bigger than the Great Auk), it was flightless like them: vestigial wings with only the humeri in the skeleton just like in the moas, short splayed legs for swimming like the auk, a long neck like a stork, and a long straight beak like an anhinga. But unlike all them, it had small true teeth.

This critter spent most of its life in water but returned on land to lay its eggs, like a typical modern seabird. Once, indeed, the hesperornis was shown as a sort of proto-penguin, and with an erect pose; we know now its legs were too weak to support its body in the manner of spheniscids or alcids, and the animal is now portrayed as more similar to modern grebes and loons. It was often depicted with the typical palmated feet like a loon, but it's more likely it had flattened toes like a grebe or a coot (a water rail). Similar to Hesperornis but smaller, Baptornis ("diving bird") also lived in the same shallow seas.

Hesperornis has long been a staple of books on prehistoric life, but it made its pop-culture debut in Primeval, where it appears as an aggressive but non-malicious creature that kills a plumber after its anomaly appears in someone's flooded basement. Its portrayal there is probably one of the worst of any extinct bird — to the point that the creature designers had it featherless (every real ancient or modern bird has feathers, even the apparently-featherless penguins) and standing upright like in the ancient classic illustrations.

1. Entry Time: 2000s
2. Trope Maker: Primeval

Toothy Seagull: Ichthyornis *

The much smaller Ichthyornis dispar lived in the same age and habitat of Hesperornis, but this time we're faced with a sorta toothed, long-billed proto-seagull. This is one of the few flying birds encountered in the Useful Notes about stock extinct birds; flightless birds, either large or small, land- or water-dwelling, seem to be the favorite ones in media — maybe because of their oddity of not-flying. But some spectacular flying birds did exist in the Mammal Age, like the "giant condors" Argentavis and Teratornis, and the giant bony-toothed "albatrosses" Osteodontornis and Pelagornis: some had the wingspan of a giant pterosaur like Pteranodon, and possibly even heavier than it.

Returning to the less-striking ichthyorn: its lifestyle was arguably similar to modern flying waterbirds, catching fishes in flight like modern terns, or maybe diving under the sea to pursue them like modern boobies. You can almost be certain that if pterosaurs are involved, these little guys will be depicted as pests who like to steal food from them, as seen with Disney's Dinosaur film: this behavior was possible, but has never been proven (modern seabirds regularly harass each other to steal their food). In Real Life ,both ichthyos and hesperos sometimes fell prey to large fish and marine reptiles, as shown by remains of stomach contents, ex. those of mosasaurs.

Despite their primitive toothed skull, the remaining skeleton of both Ichthyornis and Hesperornis was almost full birdy at this point ^note both were once called "odontognathes" ("toothed jaws"), countered against the "paleognathes" (ostriches and allies) and "neognathes" (all the other living bird groups). If alive today, apart from their teeth, they'd be easily taken for components of modern avifauna. In some artistic works, both Hesperornis and Ichthyornis are depicted as black and white like modern gulls or penguins, but their real coloration is totally unknown.

While these two do feature prominently in dinosaur books and sometimes documentaries (Hesperornis, for example, was the token prey animal in Sea Monsters and Ichthyornis got a bit part in Dinosaur Planet as a scavenger), their presence is rare in more mainstream media, presumably because, besides their teeth and Hesperornis' large size, they don't have a lot of cool points. That hasn't stopped folks from trying to portray the two stock Cretaceous birds, for better or worse. An Ichthyornis, creatively and perhaps fittingly named "Ichy" appears as a one-shot villain in the fourth Land Before Time movie, accompanied by an equally villainous crocodilian Deinosuchus. Ichthyornis also cameos in Dinosaur, erroneously depicted as duck-like creatures rather than seagull-like, and are among the many factors contributing to the start of the movie when they attack the mother Pteranodon carrying Aladar's egg, causing her to drop it.

1. Entry Time: 2000
2. Trope Maker: Disney's Dinosaur

Feathered Airplane: Argentavis *

The historically-extinct elephant birds of Madagascar are often said to have been the inspirers of the myth of the Arabian Nights flying Roc Bird, but in reality, they were huge flightless birds looking like an upscaled ostrich. The Roc title should pertain more aptly to another, this time fully prehistoric, flying bird-of-prey: Argentavis magnificens, aptly "magnificent Argentinian bird".

This has traditionally been the most famous flying bird among those living after the dinosaurs but before the modern humans (see the Haast's Eagle in the previous folder), while the most known feathered flyer among the Mesozoic full-birds is the much smaller toothed Ichthyornis above. Along with giant pterosaurs and the ancient "dragonflies" like Meganeura, Argentavis, the unrelated prehistoric seabird Osteodontornis and the lesser-known relatives of both really deserve the Giant Flyer title. This bird had a wingspan of about 7 m, as much as Pteranodon but heavier: while this pterosaur weighed about 30 kg, like a child, Argentavis weighed an impressive 80 kg, like an adult human or a small ostrich, or a small Quetzalcoatlus specimen — remember pterosaurs were comparatively lighter than birds because of their totally hollow bones. Argentavis could well be renamed the Feathered Airplane. To understand how majestic this ancient raptor was in life, imagine Argentavis as a giant condor with an emu-sized body, huge roc-like wings, a sharp hooked beak, and a love for carrion (and maybe even an occasional hunting attitude).

Found in 1980 in Argentina, Argentavis lived slightly before the famous "American Pliocenic Interchange" of fauna from the two Americas, and was nearly contemporaneous of the giant running bird Phorusrhacos. Both shared the typical eagle-like uncinated beak for tearing meat, but were not close relatives. While the phorusrhacid was basically a sorta giant flightless "secretarybird" (and often portrayed with the latter's plumage, like in Walking With Beasts), Argentavis was more like a giant vulture, but belonged to a distinct family from modern condors: the Teratornithids, and sometimes nicknamed "the giant teratorn" for this. A fairly common mistake in fiction and paleo-art is to portray Argentavis as living later than it actually did, during the Ice Age. While there were certainly teratorns during this time (namely the group's namesake Teratornis), Argentavis wasn't one of them — the ones found in the La Brea tar pits were relatively smaller, with wingspans of up to 4 m.

1. Entry Time: undetermined
2. Trope Maker: its status as "the biggest flying bird ever"

Other birds

Sorry, these aren't here. If you're looking for Aurornis, Confuciusornis, Jeholornis, Gargantuavis, Dromornis, Genyornis, Teratornis, Osteodontornis, Pelagornis, Anthropornis, Palaelodus, Presbyornis, Copepteryx, Ornimegalonyx, Amplibuteo, and others, see here.

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Long-necked Plant-Eaters

The sauropodomorphs ("sauropod-shaped") include dinosaurs with long necks. Most of them pertain to the sauropod subgroup, while all the other members are traditionally called "prosauropods" (although they are no longer considered a proper taxonomic group).

True Sauropods

Sauropods are the mostly gigantic quadrupedal plant-eating dinosaurs with long necks and tails. Some of them were the largest land animals that ever lived, but not quite as massive as they seem: the weight of most of them was brought down significantly by a system of air sacs in hollow bones, similar to theropod, and hence bird, skeletons.

Since sauropods could appear rather similar to each other in size and appearance, only a few of them will usually be identified/identifiable in Fictionland: Brontosaurus/Apatosaurus, Brachiosaurus/Giraffatitan, and Diplodocus. Their iconic status is due to several factors: the early time of their discovery, the relative completeness of their remains, and for having held some "record" in the past — the diplodocus has long been the "longest" land animal ever, the brachiosaur the "tallest" and "heaviest", while the brontosaur, being the very first mounted sauropod in a museum, was the first that became popular.

Today scientists recognize more than two hundred sauropod genera, but pop culture ignores most of them. All the three most known sauropods are from Late Jurassic North America (even though the best-known brachiosaur species was found in Africa), but in Real Life sauropods lived worldwide from the Early Jurassic up to the end of the Dinosaur Age. However, in recent years some other sauropods have received attention in media, mainly for being "the biggest yet discovered". Some really were, but other weren't even real animals. You can find them here classified as "semi-stock". Camarasaurus, Mamenchisaurus, Saltasaurus, and a few others can also make occasional appearances.

Common inaccuracies in sauropod portraits

If a writer relies on pre-Renaissance science, featured sauropod is up to its armpits in water and living in swamps while lazily munching some swamp weeds.

Before The '70s, the dominant but incorrect hypothesis said they needed to spend most of their time in water to support their massive bulk and to escape the allegedly non-swimming theropods. Modern science says sauropods were terrestrial, though able to swim in an elephant style if needed. Footprints demonstrate all this: they were mainly made on dry soil and show an elephant-like gait — however, some tracks show only the forefeet. The latter were produced by sauropods crossing a river and only touching the bottom with their forelimbs. Buoyed by internal air sacs, their hindquarters and hindlegs were suspended near the surface while swimming. If the sauropods were really swamp-specialists, they would have had a high chance of slipping in the mud with fatal consequences. If lucky enough to survive the fall, they'd starve to death from lack of nutritious food, because swamp weeds are very poor in nutrients. With their bodies submerged, their ribcages wouldn't even be capable of expanding due to water pressure, suffocating them. The alleged weakness of their teeth and the high placement of their nasal openings are not real proof for an amphibious, swamp weed-eating lifestyle. Since sauropods’ skulls have high-settled nasal openings, they are classically shown with their nostrils on the tops of their heads like the blowholes of a whale; it was recently hypothesized they might actually have been on the ends of their snouts like every other dinosaur. Finally, footprints show carnivorous dinosaurs were capable of swimming using their hindlegs as shown by the aforementioned alleged Dilophosaurus footprints, making the sauropods' fleeing in water to escape them potentially useless.

Among other mistakes when portraying sauropods, one very common is to show them with elephant-like nails or hooves, falling straight in Most Writers Are Mammals. Actually, sauropods had true claws. They usually had a thumb-claw on each forefoot (which was narrower than in modern elephants) and three claws on each hindfoot (which was broader and more elephant-like than the forefoot). The biggest known sauropod footprints, the posterior ones, can be 4 ft wide, "enough to contain a bathing child" as often stated in popular dino-books. Even so, in most portrayals that do show clawed sauropods, they usually have four or five claws on each foot.

More related to Reptiles Are Abhorrent is the tendency of depicting sauropods' necks and tails as serpentine: you'll even find brontosaurs using their necks like snakes when defending themselves. Actually, their necks had relatively few vertebrae, like a giraffe's, and were fairly stiff, especially if compared with their flexible (but still not serpentine) tails, which often had 50-70 or more bones. In the oldest scientific depictions, sauropods were often shown with splayed limbs, not pillar-like, and crawling a bit like a giant tortoise. Recently, a new study suggests that, due to the way their teeth are preserved, sauropods had a keratin covering on their mouths forming into a beak-like structure, instead of fleshy lips or toothy grins as traditionally depicted.

The Sauropod(s?) par Excellence: Apatosaurus & Brontosaurus ***

Both lived in the Late Jurassic, 154 to 150 million years ago, in what is now the USA. They were basically identical in shape: both were large but less than other sauropods, 75ft/23m long and weighing at least 23 metric tons - equal to roughly four elephants. The neck made up about a quarter of their total length, the tail about half. Their overall size is often exaggerated in popular writing, for instance by claiming that Brontosaurus weighed as much as 10 elephants, or even that it was the largest dinosaur (one could assume the writer knew only one type of sauropod).

The head was small and slender; the teeth were peg-like and found only at the tips of the jaws. The neck had more than 10 vertebrae, and was of average length but wider than in other sauropods. The body was stocky and deep; the hips were taller than the shoulders. The legs were robust, even more so than in most sauropods, the hindlimbs longer than the forelimbs. The tail was very long with about 80 vertebrae, thin and whiplike near the end.

Apatosaurus is one of the few sauropod genera already known to science when dinosaurs entered pop culture in the 1900s. Marsh described the first species in 1877, in full Bone Wars context, but its first remains were incomplete. Just two years later, Marsh described a second alleged Apatosaurus species as a distinct animal, Brontosaurus excelsus. The latter became the iconic image of a sauropod for most the 1900s. Brontosaurus and Tyrannosaurus were the ultimate stock dinosaurs in their respective roles as herbivore and carnivore, and contenders for the title of THE overall most iconic dinosaur. In classic dino-stories the brontosaur's (or other sauropods') designated role is the Gentle Giant Sauropod, while T. rex or Allosaurus is the Big Bad, Stegosaurus the Dumb Dino or the Tough Armored Dinosaur, Triceratops the Temper-Ceratops, the "raptors" the Small Baddies, ornithopods the Friendly Fodder... unless Everything is Trying to Kill You, of course. In the classic version of King Kong, brontosaurs are meat eaters.

Why has Apatosaurus long been considered the only correct name for this pair of dinosaurs? Because scientific rules say if one animal is assigned two scientific names only the first one is valid, and "Apatosaurus" was coined two years before "Brontosaurus". The latter means "thunder lizard" (probably a reference to the booming sounds sauropods might have made when walking), while the former means "deceptive lizard" — a much less cool name but, surprisingly, the most apt one.

And then, why has just Brontosaurus been the traditionally most popular sauropod, despite being smaller than Brachiosaurus and shorter than Diplodocus? Probably because it was hyped up to be the biggest dinosaur of all time and had that name attached to it. The first-ever mounted display of a sauropod skeleton erected at the American Museum of Natural History in 1905 was based on a mostly complete Apatosaurus skeleton, with missing parts borrowed from other sauropod specimens — which also gave the display skeleton a short, boxy head and blunt tail, both incorrect. However, the Museum chose to label the display "Brontosaurus". Other museums followed suit with similar Brontosaurus displays. Popular writing and dino-art kept spreading the at-the-time incorrect name, and the ghost of Brontosaurus still haunts Apatosaurus, as does the image of the short, round head — even though the long-narrow-head portrayal is starting to become more known among general public. The actual apatosaurian skull was discovered only in year 1975, and is long and flat like that of its relative Diplodocus, not short and round like in the first Brontosaurus mount.

Peter Jackson's King Kong (2005) referenced all this situation by having a newly-discovered dinosaur on Kong Island be named Brontosaurus in the special features on the DVD. A nice homage, but in reality, once a name is used, even if it's invalidated, it can never be used again for a new animal, lest later researchers be left with no idea which Brontosaurus you're talking about.

Even though the name "Apatosaurus" is today more known among common people than before thanks to documentary media, it could fall again in oblivion if certain proposals are confirmed in the next few years. Since the early 20th century the genus Apatosaurus has traditionally included Apatosaurus ajax (the first described species: Ajax was a Greek hero of the Iliad poem renowned for his great height and strength), Apatosaurus excelsus (excelsus = elevated), and Apatosaurus louisae (for Andrew Carnegie's wife Louisa), plus two lesser-known species (A. parvus and A. yahnahpin, the latter sometimes known as Eobrontosaurus). However, in 2015, a new study re-classified Apatosaurus excelsus, A. parvus, and A. yahnahpin in the genus Brontosaurus after finding enough differences between them and A. ajax + A. louisae together. If further studies ultimately confirm this proposal, both genus names will be validated, with the more famous species becoming Brontosaurus once again, which would be very bad news for people who like correcting other people.

Winsor McCay's famous 1914 Gertie the Dinosaur made Brontosaurus the very first dinosaur in cinema, and the very first character originally created for an animated cartoon. Interestingly, she's shown as a land animal, anticipating a largely-discarded theory for more than half a century. Gertie is basically portrayed like a domesticated elephant, and, interestingly, has the correct head shape for a brontosaur: since the brontosaurian head was considered round at the time, some hypothesize she's actually meant to be a Diplodocus.

1. Entry Time: 1877/1905
2. Trope Maker: Itself

Immense Tail: Diplodocus ***

Carnegie's Double Beam

Living in western North America during the Late Jurassic Period (154-150 million years ago), Diplodocus was a neighbor of Brontosaurus & Apatosaurus. These three dinosaurs belonged to the same family, Diplodocidae, and many features of Brontosaurus & Apatosaurus (the whip-like tail, the skull shape, and the longer hindlimbs) are shared by Diplodocus. Unlike the bronto/apato's ones, Diplodocus' portraits have always had a narrow-ended tail and the long head with a flattened snout typical of diplodocids - the Diplodocus' skull and tail-end have been known since the first discoveries. This means the two animals can be easily distinguished from each other in older media. The aforementioned "Gertie" is NOT a good example, being similar to a brontosaur in bulk but to a diplodocus in head, with unrealistically short stub tail of a brachiosaur, and classic elephantine feet and serpentine neck/tail of outdated portrayals.

In more updated depictions, their overall profiles are the main key to telling Diplodocus from Brontosaurus, at least, in documentary media: in cartoons and pop-images (even the most recent ones) you'll easily find both diplos and apato/brontosaurs portrayed with a very generic, "brontosaur"-like look, making them impossible to tell apart. The diplos were actually longer than the apatosaurs and the brontosaurs, from about 80ft/24m to 115ft/35m, but weighed only about half as much: 10-16 metric tons. The Diplodocus shape was slenderer and more elegant than the robust Apatosaurus & Brontosaurus, with a longer, slimmer neck; these differences allowed these animals to live side-by-side and avoid competition by browsing different kind of vegetation, since the diplodocus was able to reach higher tree-food. In a sense, Diplodocus was the giraffe of its world, while Bronto/Apatosaurus was the elephant: an "elephant with the head atop of its trunk", to quote Dale Russell.

Diplodocus has classically been qualified as "the longest dinosaur", but this record is now contended by other diplodocids, like Supersaurus. All diplodocid sauropods had long tails, but Diplodocus took this to an extreme: its tail was 14m/40ft long, longer alone than a whole T. rex was from nose to tail! The apatosaur's tail was "only" 10m/30ft long, but curiously, the Diplodocus tail had slightly less vertebrae than Apato/Brontosaurus: about 70 vs 80. This could mean that the tail of the latter was a bit more flexible. It has been speculated that the thin end of the diplodocids' tail could have been used as a whip directly against threats, or indirectly by making whip-cracking sounds. The tail vertebrae of diplodocids also had double beams (hence the name Diplodocus: "double beam") that may have protected the blood vessels inside the tail when the tail pressed against the ground. Diplodocid sauropods may have used their tails as a support together with their hindlimbs, lifting their forequarters to reach higher vegetation.

Found during the Bone Wars like Apatosaurus and Brontosaurus, Diplodocus was introduced to the public courtesy of Andrew Carnegie some decades later. He sponsored an expedition that discovered a new Diplodocus species (which was named Diplodocus carnegii), and had the remains mounted in his museum in Pittsburgh. He then donated replicas of it to museums all over the world (the most iconic of these being "Dippy" of the London Museum of Natural History); as a result, in some European nations, ex. Britain and France, Diplodocus became the iconic sauropod, rather than "Brontosaurus" as in the USA. This isn't universal however; in other European countries, like Italy, the brontosaur is still regarded as the prototypical sauropod.

In recent years, the British Speculative Documentary Walking with Dinosaurs has popularized some recent theories about Diplodocus and sauropods in general: the straight, horizontal neck posture and the iguana-like spiky back. The first is due to analysis of the neck vertebrae using computer models. Unlike mammals, sauropods had pairs of ribs even in their necks; the shape of these ribs, together with the relatively low number of cervical vertebrae, prevented their necks from being coiled in a snake-like manner. The second arose from a discovery made in the 1990s of a diplo with imprints of horny spikes near its back. Both theories are now disputed: both the base and the end of the sauropods' necks were more flexible, and the animals may have been able to fold their necks and lift them like most modern long-necked animals. The spikes were dermic boneless structures not related to the skeleton; dinosaurs being closer to birds than to lizards, the structures might have been spread over the animal's back like theropod feathers, instead of in a single line like an iguana's. We don't know if other sauropods had similar fleshy/horny spikes, but spiky iguana-like longnecks have been a common sight in books and art in the 2000s — as it seems, dino-artists have had hard work getting rid of the Dinosaurs Are Dragons idea.

1. Entry Time: 1905
2. Trope Maker: The Carnegie Museum skeleton and subsequent replicas, such as "Dippy"

Huge Giraffosaurs: Brachiosaurus & Giraffatitan ***

High Chested Arm Lizard

Brachiosaurus is the third member of the iconic sauropod Power Trio and lived along Brontosaurus, Apatosaurus, and Diplodocus in Late Jurassic North America, 154-150 mya. This detail was mentioned as a concrete proof about the Pangaea hypothesis, as brachiosaurs weren't able to cross oceans to migrate from one landmass to another - the continents were still not completely separated from each other in the Jurassic.

From its first description at the start of the 20th century, Brachiosaurus was often considered unofficially "The biggest land animal ever!" until real or alleged new sauropods were described starting in the 1970s. Of course, works made after The '70s may still qualify the brachiosaur in this way: sadly, among them, even Walking with Dinosaurs, at least the original series. Generally thought to weigh between 30 and 50 tons (more than the stock sauropods above), Brachiosaurus has often also been oversized in popular books, so far as to triple its size up to 130 tons, which would make it heavier than any animal alive today, except for the blue whale.

Brachiosaurs are visually distinct from diplodocids in several ways. First, their necks were noticeably longer than their tails, and their backs sloped backwards instead of forwards, just like a giraffe. Going into more detail, their tails had a thicker end lacking any thin "whip"; their necks were stronger, had more vertebrae and were held more vertically, again like a giraffe; their teeth bordered most of their jaws and were chisel-like, not peg-like; their nasal openings were unfused, placed more forward, and were much wider than diplodocids' (the brachiosaur subgroup of sauropods, "Macronarians", just means "large nostrils"). In the past some paleontologists suggested sauropods had a tapir-like proboscis observing the shape of their skull! Finally, brachiosaurs are almost the only non-bird dinosaurs with forelimbs longer than hindlimbs (Brachiosaurus means "arm lizard"). Sometimes these differences get glossed over in popular media, which may show brachiosaurs with diplodocid heads, necks, bodies, legs, and/or tails. In these cases, they might be recognizable as brachiosaurs only thanks to a more upright body shape.

As with other sauropods, brachiosaurs were associated with water in older reconstructions. To accommodate their upright shape, they were often shown totally submerged in lakes, not simply wading like diplodocids, with only their head and, sometimes, only their nostrils above the water level, making their neck like a giant snorkel. Needless to say, this is quite unrealistic. In modern portrayals, Brachiosaurus has often been described as a "prehistoric giraffe" capable of browsing the highest vegetation that other sauropods were not capable of reaching — unless diplodocids were able to stand upright on their hindlegs. Brachiosaurs probably weren’t capable of that, having their center of gravity much farther forward, and their shorter tails didn't provide support (they would only bring a little bit of extra reach anyway). Moreover, as their greater size could have automatically protected adults even against the biggest predators, they probably didn't need to lift their forebody and use the front-legs to fight an Allosaurus or so, nor didn't they need to use their short tail to hit it to death (Diplodocus, Apatosaurus, and Brontosaurus probably did both of these).

However, in fictional and sometimes even documentary media, brachiosaurs show unusual athletic skills: in Jurassic Park, a brachiosaur rears up on its hindlegs to reach a tiny branch. In Disney's Dinosaur, the brachiosaur Baylene is able to remain in a fully erect position for 30 seconds to break the wall of a cave with her forefeet. Also in Jurassic Park, the brachiosaur is shown with an oversized head with fleshy lips, chewing vegetation like a cow. Sauropods didn't chew: their teeth were more suited to cutting plant material in the case of the brachiosaur, or to raking it like a comb like the diplodocids.

Strangely, before the '90s Brachiosaurus was an unusual sight in cinema, much rarer than Brontosaurus and Diplodocus despite its record size. Then, in 1993, Spielberg made a brachiosaur the solemn show-opener of his first film (Crichton's eponymous novel had Apatosaurus in this role). Thanks to this and possibly to its cooler look, the brachiosaur has become one of the most frequent longnecks in popular works since then, and many "young" dino-fans now consider it THE iconic sauropod in pop culture, sometimes even using the word "brachiosaur" generically as if it was a synonym of "sauropod", while pre-JP dino-fans still tend to think of Brontosaurus (in the USA) or Diplodocus (in Britain) in these roles — of course this is a very rough distinction, since all three dinosaurs are actually very popular in every country.

Brachiosaurus has gone through some naming troubles, but its situation isn't as severe as the traditional Apatosaurus-Brontosaurus deal — the name Brachiosaurus has always been valid, however its best-known species, the Tanzanian B. brancai, had to be placed in a different genus, named Giraffatitan. Gregory S. Paul first suggested they were distinct in 1988; this suggestion was followed by George Olshevsky in 1991 and Dougal Dixon in 2006 - otherwise, it was not taken seriously until Michael Taylor proved Paul, Olshevsky and Dixon correct in 2009. Additionally, the Portuguese species, B. atalaiensis, was reclassified as Lusotitan in 2003.

Giraffatitan brancai ("Branca's titanic giraffe") was found in Tanzania at the Tendaguru site two decades after the U.S. brachiosaur (Brachiosaurus altithorax, "tall-chested arm-lizard"), and is known from complete remains which show a distinctive domed skull. An impressive, 12 m tall Giraffatitan skeleton was mounted in the Berlin museum in the 1930s during the Nazi regime, making this dinosaur the most iconic sauropod in Germany: this was also the biggest mounted dino-skeleton until two decades ago, the only brachiosaur mount worldwide before recently, and the model of the popular image of the brachiosaur lasted for decades around the world. On the other hand, the valid Brachiosaurus was long known only from fragments, and its skull wasn't described until the 2000s. This skull, which had a smaller dome than Giraffatitan's, was long classified as another kind of sauropod, Camarasaurus (see below); ironically, it was just this skull that was put in the original "Brontosaurus" skeleton. The old pop-cultural "brontosaur" is thus just a Mix-and-Match Critter made of Apatosaurus and Brachiosaurus. To this day however, most pop culture depictions of Brachiosaurus are in fact modelled on Giraffatitan, such as the one from Jurassic Park or Baylene from Disney's Dinosaur.

1. Entry Time: 1930s
2. Trope Maker: The mounted skeleton at the Berlin Natural History Museum (now recognized as Giraffatitan)

Size Matters: the "Heavy-weight" Sauropods **

Let's face it — paleontologists are people too. While they carefully excavate fossils in some dusty badlands location, or sort through boxes of collected fossils in chilly museum basements, they can't help but secretly hope to be the one who discovers or describes Badassosaurus mynamii. Sometimes they do strike gold. Most of the time, they report an unremarkable animal and get the satisfaction of a job well done but very little glory. Then, there are cases like these...

• "Ultrasaurus" the "Ultra-lizard" is a story written across The '80s and The '90s about two sets of bones and one name. The U.S. set (a bit of backbone and a shoulder girdle, from Colorado) was in 1979 described by James Jensen as Ultrasaurus, the largest dinosaur ever... to the press, not in a scientific paper. It was depicted as a brachiosaurid 30 m long, 16 m tall and with a weight up to 130 tons, making it even bigger than the former record-holder, Supersaurus — which, by the way, was also described by Jensen a few years before, always in Colorado. The South Korean set (a bit of backbone and an upper forearm) was described a few years later as an Ultrasaurus. This, however, prevented the U.S. animal from being called Ultrasaurus officially, so they had to settle for "Ultrasauros" in 1991. It was still the largest dinosaur, though. Well, at least for a few years, until it was realized that the U.S. set of bones was actually from two different animals, a Supersaurus and a Brachiosaurus: the name "Ultrasauros" was consequently discarded in favor of Supersaurus. Before that, the U.S. ultrasaur showed up in some documentaries, and is cited in Calvin and Hobbes as well as in the first JP novel (which mentions the following example, too).

• "Seismosaurus". In the early 1990s Ultrasaurus had to face a rival for "the biggest" title: the "Seismic lizard", popularly nicknamed the "Earth-Shaker". A diplodocid from New Mexico with an estimated length of 177ft/54m and an estimated weight of 112 tons, which makes it almost twice as long as a blue whale, and almost two thirds of the blue whale's weight. Impressive? Well, when other experts got a look at it they determined that the size calculation had been thrown off by misplaced vertebrae, that 95-110ft/29-33m was a more accurate estimation, and that the seismosaur was simply an old, well-grown Diplodocus. The name Seismosaurus is now discarded.

• Supersaurus the "Super-lizard", as said above, was found in Colorado in the 1970s, but is also known from Portugal (where it was originally identified as Dinheirosaurus). It was described from a few bones as a brachiosaurid of unusual size, twice as long as Brachiosaurus, and hailed as the first sauropod "bigger than the brachiosaur". When more remains were found, Supersaurus was reclassified as a diplodocid, longer and more massive than those previously known but not excessively so. However, an analysis of the fossils in 2016 suggested that, like Seismosaurus, it also might simply be an overgrown specimen of a better-known dinosaur: Barosaurus, in this case — the hypothesis that Supersaurus and Barosaurus were the same animal was already postulated in the eighties, but was discarded by most experts at the time. More recent analysis of the fossils in 2021 has suggested that Supersaurus was its own genus after all. A neck vertebrate, known as BYU 9024, is also tentatively assigned to Supersaurus (although it's gone back and forth between it and Barosaurus) which suggests some individuals could well over reach over 40 metres in length (some estimates put it at possibly over 50 metres, which would make it, by far, the longest known dinosaur).

• Argentinosaurus was discovered in Argentina in 1993. It lived in the Early Cretaceous, 95 mya, unlike the more famous sauropods which were Late Jurassic. Argentinosaurus belonged to a group of sauropods called titanosaurs, which evolved within the Titanosauriformes (which included Brachiosaurus and Giraffatitan) and replaced the earlier sauropods worldwide in the Cretaceous. Titanosaurs are based on Titanosaurus, which was first described in 1877 and used as a "wastebin taxon" since then (see its entry below). The classification of titanosaur genera is still in debate and many, including Argentinosaurus, are based on fragmentary remains. We don't know how its head looked exactly, because the argentinosaur's skull is not among these remains. New finds and further cladistic research may still change the descriptions of these animals. Titanosaurs seem to have been more compact than earlier sauropods, with shorter necks and tails, solid bones, and wider frames. At least some titanosaurs had crocodile-like skin armor; in one case (Saltasaurus) this was fully developed as bony plates similar to the ankylosaurs. On the other hand, Argentinosaurus probably didn't develop an armored skin. Length and weight estimations of Argentinosaurus are necessarily speculative, but the consensus seems to put the length at 100ft/30.3m (like Diplodocus) and the weight at about 75 metric tons (about twice a Brachiosaurus). ^note Another South American titanosaur, Antarctosaurus, has left some possible remains almost the same size of the argentinosaur, which were found several decades before 1993. Being very scant and dubious, they have been largely ignored. Other sauropods were previously estimated as even heavier than 75 tons, but these valuations appear positively exaggerated. Such heavy land animals would haven't even able to survive, and the blue whale still remains the official record-holder of all time: only other sea creatures could have overweighed it in the past. In 2002, Chased by Dinosaurs featured a herd of Argentinosaurus. In a memorable scene, Nigel Marven hurries to place weight sensors in front of the herd as it approaches, walking straight towards the camera and messing with the viewer's perspective: a very effective demonstration of the immense size of these animals. Strangely, unlike its predator Giganotosaurus,^note  This is actually a case of either Misplaced Wildlife or Anachronism Stew; the two species were found in different formations, with "giga" being slightly older.Argentinosaurus has not received much attention in fiction since then. Maybe because, size-related impressiveness apart, the Argentinosaurus here do nothing sensational — the adults continue to walk apparently unmoved after the Giganotosaurus bring down one of their young. On the other hand, Argentinosaurus became popular among dino-fans for being described as "the biggest ever dinosaur" in the show and in the dino-books of the last decades. ^note This is not an isolated case. Several other sauropods have at one point been described the same way since the very first sauropod discoveries. One of the first was the dubious Atlantosaurus "Atlas lizard" in the late 19th century (see Prehistoric Life - Dinosaurs). Many others followed since then, with scientists seemingly competing with each other for who coined the most awesome name — Argentinosaurus is one of the rare exceptions, meaning simply "lizard from Argentina".

• Sauroposeidon (in reference to Poseidon's lesser-known status as the god of earthquakes, and the animal's great size) was described in 2000 based on four extremely elongated neck vertebrae found in Oklahoma which were, incidentally, first thought to be petrified logs. It might have had the longest neck of every creature ever, even longer than the neck of Mamenchisaurus. It was thought to be a brachiosaur at first, but data published in 2012 puts the "Poseidon lizard" closer to the titanosaurs: a non-brachiosaur titanosauriform ("titanosaur-shaped"), maybe an almost-titanosaur. As such, its size is uncertain—the new interpretation gives us an animal up to 115ft/34m long and weighing 50-60 tons. Living in Early Cretaceous USA along with Deinonychus, Clash of the Dinosaurs depicted Deinonychus bringing down a full-grown Sauroposeidon which, for some reason, is shown living in the Late Cretaceous.

• Paralititan ("tidal giant", described in 2001) is one of the several titanosaurians found after Argentinosaurus and cited as possible contenders of for "the biggest" title: others are Puertasaurus (described in 2005), Futalognkosaurus (described in 2007), Notocolossus (described in 2016), Patagotitan (described in 2017), and the coolly-named Dreadnoughtus (see below for the latest one). Several of them are part of a titanosaur clade aptly named colossosaurs in 2019 (a group that included also Argentinosaurus and other South American titanosaurs), but others, like Paralititan and Dreadnoughtus, weren't members of the colossosaurians. From the same time and place as Spinosaurus, Paralititan is known from a bit of backbone, a shoulder girdle, and an upper forearm. By comparing the bones with the skeleton of a more complete titanosaurid such as Saltasaurus, Paralititan appears to have been 85ft/26m in length and have weighed 59 metric tons. You know, unless it turns out to be a mistake.

• Bruhathkayosaurus. Found in India in the 1990s, this one is, for now, the biggest example. Described as a titanosaurian sauropod of uncertain placement in the evolutive tree, and believed to have weighed 126 metric tons, it was originally estimated at up to 220 tons: even heavier than the blue whale. However, its formal description is extremely inadequate, and it was at one point speculated that the leg and hip bones found were actually petrified wood. The tibia, incidentally, was gigantic— at six feet long, it was nearly one third bigger than that of Argentinosaurus. But this is not all: our complex-named giant (Bruhathkay means "huge-bodied" in one of the many languages of India) was initially regarded as a theropod. Imagine a carnivorous dinosaur 50 times heavier than a T. rex... Bruhathkayosaurus must join Maraapunisaurus below as another "one that got away"; it seems that its bones were never properly stored out of the elements and got washed away during rainstorms. However, in 2022 photographs of the original fossils were finally uncovered, proving beyond a doubt that it did exist. However, the photos are of poor quality, and it has even been suggested that the giant tibia was not a tibia at all but a badly degraded femur, in which case the whole dinosaur would have been closer to Dreadnoughtus or Paralititan in size.

• Maraapunisaurus was believed to be a diplodocid that would have been 190ft/58m long, and weighed 120 metric tons, making Diplodocus look like a Labrador retriever in comparison... but the only find since 1878 is a single vertebra, which has been lost. For a long time, this vertebra was classified as a different species, called Amphicoelias fragillimus within the poorly-known diplodocid genus Amphicoelias (a very incomplete sauropod found in the Bone Wars, maybe another synonym of Barosaurus). The meaning of "Amphicoelias fragillimus" is surprisingly bland for one of the most celebrated "heavyweight" sauropods of the Turn of the Millennium and The New '10s: "extremely fragile hollow vertebra". This discovery of the 19th century was long largely forgotten until its original description made by Edward Cope became more widely-known since the 2000s, mainly in Internet circles. However, a more thorough analysis of the vertebra in 2018, based on surviving drawings, suggests that Amphicoelias fragillimus was not a diplodocid at all, but a member of a different family called the rebbachisaurids. A new name was therefore created for it— Maraapunisaurus, from the Southern Ute word meaning "huge". Rebbachisaurs had very big vertebrae in proportion to their bodies, so if it was a rebbachisaurid, Maraapunisaurus might not have been the largest dinosaur after all, although still very large (over 115ft/34m long and 70 metric tons). However, some have raised suspicions of Cope's description, with suggestions of possible miscalculations or even deliberate exaggeration in an effort to one-up his rival Othniel Marsh having been proposed.

• Dreadnoughtus was a basal titanosaur discovered in 2005. It had a 45% complete skeleton, and was officially described in 2014. Given that few of the bones were duplicates from the left and right sides of the "Dreadnought Dinosaur" (full scientific name: Dreadnoughtus schrani), it's de facto 70% complete. As most titanosaurs (and most very large sauropods in general) have only had specimens less than 10% complete, this means that while Dreadnoughtus is (probably) not the largest titanosaur, it's the dinosaur with the greatest mass that we can be reasonably certain about, at around 38 metric tons - and the specimen in question is believed to be a juvenile, so a full-grown adult might have been much bigger. Since the second half of the 2010s, giant titanosaurs have more and more often been depicted with long muscular upright necks and comparatively-short tails (like in brachiosaurs and mamenchisaurs), but the actual mass/length of their necks and tail is uncertain. Dreadnoughtus is a very rare example of a dinosaur with an English-inspired Latin name, and has started to become popular since the end of The New '10s. It first appeared on television in May 2022 with Prehistoric Planet and on the big screen in June with Jurassic World Dominion.

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So, which one is the biggest? Depends on the chosen criteria. Good luck to all of you bone-diggers out there.

• The Longest: Maraapunisaurus if it was a diplodocid; Diplodocus-Supersaurus-another diplodocid otherwise.
• The Tallest: Sauroposeidon if it was a brachiosaurid; Brachiosaurus-Giraffatitan-another brachiosaurid otherwise.
• The Heaviest: Bruhathkayosaurus if it was really as big as it was claimed; Argentinosaurus-Patagotitan- another titanosaurian otherwise.

1. Entry Time: 1970s, 1980s, 1990s, 2000s, and 2010s according to the species: 2002 for Argentinosaurus
2. Trope Maker: Sensationalism in media and wishful thinking among paleontologists.

A Common Sauropod: Camarasaurus *

Who's the most common sauropod in the USA, Apato/Brontosaurus, Brachiosaurus, or Diplodocus? None of them. It was Camarasaurus. Yes, Camarasaurus, not "Camarosaurus". "Camara" in Latin means "cavity", a reference of the classic cavities present in most sauropods' vertebrae, included this one.

This dinosaur was as enormous as the former: 18 meters long, a bit shorter than an apatosaur but with the same bulk, and all them shared their same habitat in which other two popular dinosaurs lived, Stegosaurus and Allosaurus. And yet, when was the last time you’ve heard “Camarasaurus” in a film/cartoon/comic? Even the famous Speculative Documentary Walking with Dinosaurs has totally ignored it, preferring its cousins instead. The misfortune of Camarasaurus is probably due to not detaining any size-record among sauropods: it has not been either “the longest” like Diplodocus, or “the tallest/heaviest” like Brachiosaurus. Furthermore, its first complete skeleton (found in the early 20th century in the Dinosaur National Monument between Utah and Colorado) was from a juvenile, leading some books telling the camarasaur was "one of the smallest sauropods". On the other hand, other dino-books have said this dinosaur was 40 m (130 ft long) long and that was "one of the biggest dinosaurs"!

Discovered during the Bone Wars, Camarasaurus is considered by some a rather unsauropod-like sauropod, because of its relatively large head and its much-shorter neck compared to most other sauropods. It tended to be confused with Brontosaurus in the past, because the classic brontosaur portraits have a round head and a short, blunt tail, just like Real Life camarasaurs. Until few years ago, the head and tail of the skeleton at the base of the popular "brontosaur" image were believed belonging actually to a specimen of the "camara", so in books it's classically said "The brontosaur's traditional pictures have the head of Camarasaurus". We now know this fossil pieces came from a specimen of the North American Brachiosaurus.

Camarasaurus was more related to Brachiosaurus than to Apatosaurus. Both the brachiosaur and the camarasaur had short, boxy skull with wide nasal openings, a nasal crest, and relatively large teeth which bordered the whole jaws - the Diplodocus and Apatosaurus skull was longer and flatter with peg-like teeth only on the jaw-tips. The four legs of Camarasaurus were about the same length, and its back was perfectly horizontal and perhaps even a bit taller on the shoulders: Apatosaurus and Diplodocus has shorter forelimbs than hindlimbs, and their back had a convex silhouette with the tallest point on the hips. With its short neck, Camarasaurus arguably ate lower tree-vegetation than diplodocids and brachiosaurs; we don't know if it was able to lift up on its hindlegs and tail to reach higher foliage, given its barycenter was more forward than diplodocids, but more backward than brachiosaurs. Even though its tail lacked a "whip" end, it was comparatively longer than a brachiosaur's, and could have been used to hit predators as defense like what diplodocids probably did.

Some suspect that some Camarasaurus are present in Fantasia and in the sequel of The Land Before Time dedicated to migrating sauropods, but both portrayals are unnamed. It certainly appears in some CGI documentaries and many dino-books, thanks to its status of "the most common longneck of Jurassic North America".

1. Entry Time: 2001
2. Trope Maker: When Dinosaurs Roamed America (documentary)

Colossal Neck: Mamenchisaurus *

What is the thing that has really made sauropods the most iconic plant-eating dinosaurs? Their size, useless to say. But there are few doubts that their unbelievably long necks have done their part, too. But wait: if you think Brachiosaurus and Diplodocus have disproportionately vast necks, it's only because you’ve never seen their Chinese cousin: Mamenchisaurus ("Mamen Brook lizard"). The latter’s neck was so long that, if the animal would still be alive today, we could see it drinking some water from a lake with its forelimbs placed 12 m (35 ft) or even 15 m (45 ft) from the shore! In other words: the neck of Mamenchisaurus alone was longer than a whole T. rex, like the tail of Diplodocus alone. This record has made Mamenchisaurus one of the most famed sauropods and one of the most classic Chinese dinosaurs. It’s worth noting, however, that the classic record of “Whoa the longest-neck!” is now disputed by Sauroposeidon, and other sauropods whose actual length of their necks is only speculative. One of them, the recently-discovered Xinjiangtitan also of Asia, was related to Mamenchisaurus but possibly bigger.

Mamenchisaurus lived in the same age of the other stock sauropods (Late Jurassic), but one species reached Early Cretaceous (although whether it is a Mamenchisaurus or just a relative has been brought up). It was described in 1954, much later than its North American cousins, but was nonetheless one of the first-found dinosaurs in the People's Republic of China. Initially believed a close Diplodocus relative, it is now thought to be a more archaic kind of sauropod which incidentally reached a similar shape, though with a much shorter tail not ending with a "whip" but with a small club (the "club" is a very recent discovery, and almost every mamenchisaur depiction shows it clubless). Since the head of Mamenchisaurus has long been unknown, the most classic portraits show it with an inaccurate Diplodocus-like head; actually, Mamenchisaurus's head was more similar to Camarasaurus or Brachiosaurus. In short, the polar opposite of what has happened to the allegedly boxy Apatosaurus head. Like Camarasaurus, it's controversial if the mamenchisaur could lift on its hindlegs, given the weight of its neck and the shortness of its tail: but if it could so, it could have reached an impressive 20 m (60 ft) of height, beating even the brachiosaurs.

To date, the only significant appearance Mamenchisaurus has made in pop-culture was a simple cameo in The Lost World: Jurassic Park, where it's unidentified and unnamed, but it is very common in dinosaur books and older documentary media because of the size of its neck.

1. Entry Time: 1997
2. Trope Maker: The Lost World: Jurassic Park

Eight Hearts?: Barosaurus *

Overshadowed by Awesome seems a common trope among dinosaurs. We see a dinosaur, remain struck by its awesomeness... but later, another similar yet even cooler dinosaur takes its place in our mind. Barosaurus could be an example. 8/9 m long, its neck was one of the longest in the whole Animal Kingdom... but is definitively overshadowed by the 12/15 m long neck of Mamenchisaurus (as well as that of the brachiosaurs).

Discovered in the USA at the end of the Bone Wars, Barosaurus was one of the closest relatives of Diplodocus, and lived as well in Late Jurassic North America; some possible remains from Africa are also known, but are generally thought to be from a different genus, Tornieria. Barosaurus was virtually identical to Diplodocus except for its shorter tail counterbalanced by the longer neck. It was one of the longest sauropods, only a bit shorter than Diplodocus. Barosaurus means “heavy lizard”: though apt for a sauropod, it's not totally appropriate. Having the same slender frame of Diplodocus, the barosaur weighed less than other sauropods. The Barosaurus' lower notoriety is probably due to the fact that its remains have been less abundant than the Diplodocus ones. However, Barosaurus has gained more fame when a barosaur skeleton was mounted in the American Museum of Natural History in the 1980s, while. This skeleton is the dino-star of the museum, being mounted erected on the hindlimbs and the tail; 15 m tall, is shown defending its youngster from an attacking Allosaurus. Another (nicknamed Gordo) was mounted in Useful Notes/Toronto's Royal Ontario Museum in 2007. In the same years as NYC's, one bizarre suggestion was made about its physiology: with such a long neck, Barosaurus may have had eight hearts to pump blood up to its lofty head. These "hearts" were imagined to be placed through the neck, and pulsating synchronically to enhance the blood circulation. There could actually be a bit of reality in this idea: pulsating blood vessels are not unknown in the modern animal world. The problem is... there isn’t any evidence to prove all this true on Barosaurus.

1. Entry Time: undetermined
2. Trope Maker: the upright skeleton in New York's American Museum of Natural History

Armored Longneck: Saltasaurus *

When we think about “armored” dinosaurs, our mind automatically goes to things such as Stegosaurus, Triceratops, Ankylosaurus. Thus, if you are a layman, you could be astonished if we tell you that there were also armored sauropods. Scientists themselves were surprised when such an animal was really discovered in 1980 in the Argentinian province of Salta: they called it Saltasaurus loricatus, meaning "the armored lizard of Salta". It walked around 80 million years after the more popular "three stock sauropod band", almost managing to see the meteor.

Saltasaurus armor was different-looking than Ankylosaurus armor, and more similar to that of a mammalian glyptodont. It had no spikes, and was made by several small round bony scutes of two different size, covering all the upper parts of its torso like a mosaic (some portraits wrongly show this armor covering also the upper neck and tail, courtesy of John Sibbick). Though apparently much lighter than an ankylosaur’s, it would have been enough to defend the sauropod against predators like the contemporary “horned” Carnotaurus. Its tail was robust, so the saltasaur was probably able to lift itself on its rear-legs despite the weight of its armor. We don't know if Argentinosaurus or other colossal armorless titanosaurs were able to do so.

The scientific importance of Saltasaurus raised up even more after the discovery made at the end of the 1990s of a fossilized breeding-site full of nests and hatchlings, the very first known from a sauropod. These remains were attributed to Saltasaurus, but we are not sure if they pertain to its genus. Saltasaurus is also a member of that subgroup of sauropods called titanosaurs: since its discovery, armor plates of several other titanosaurs have since been found, although more incomplete. Other armored sauropods were found before the description of Saltasaurus, but were so fragmentary they were believed ankylosaurs or even crocodiles, ex. Loricosaurus, "armor lizard". Another allegedly armored sauropod, "Lametasaurus", was described in India from mixed remains of crocs, titanosaurs, and carnotaur relatives!

Saltasaurus was also considerably smaller than all the sauropods above: it was "only" 12 m long and not much heavier than an elephant. Not counting the bony plates, its shape was that of a generic sauropod, with forelegs shorter than hindlegs and middle-length neck and tail. Oddly, Saltasaurus was once much more common in popular dinosaur books in the late 1980s and early 1990s than it is today, often being mentioned as one of the few Cretaceous sauropods. We now know that titanosaurs were actually quite successful during this period, and many of them possessed the same kind of bone armor that Saltasaurus did. Therefore, its relevance in popular culture has declined somewhat.

1. Entry Time: 2003
2. Trope Maker: Dinosaur Planet

Titans Everywhere?: Titanosaurus *

Titanosaurus is the official archetype of the titanosaurian group. Found in India at the same times of the American Bone Wars, its name was also given by Edward Cope to a fragmentary U.S. diplodocoid sauropod Othniel Marsh renamed "Atlantosaurus" few months later (although it's now considered dubious). Similarly-sized to Saltasaurus, Titanosaurus was the first titanosaurian known by science, and perhaps even the first dinosaur found and described in Asia (long before Protoceratops or Velociraptor in Mongolia, see Prehistoric Life - Dinosaurs). Then the genus Titanosaurus was given to many undetermined sauropod remains hailing from Cretaceous around the world (Argentina, Europe, etc.), making it a Wastebasket Taxon like Iguanodon or Megalosaurus. Most of these are now deemed dubious or have been since reassigned into different species, such as Isisaurus, Rapetosaurus, Magyarosaurus, and Neuquensaurus. Unfortunately, that leaves the remaining Titanosaurus fossils far too dubious to be properly distinguished, and the dinosaur has since fallen into taxonomic limbo, much like Troodon did in the late 2010s.

In Prehistoric Park some "titanosaurs" appear in the third episode together with the Microraptors in Cretaceous Asia, but in China and not India, which was an island separated by the rest of Asia at the time thanks to the moving of the continents. Since the episode set in Early Cretaceous, they were not Titanosaurus, but an unidentified species based on remains that would later be named Dongbeititan and Liaoningotitan (neither of which are true titanosaurs).

The movie Terror of Mechagodzilla features a dinosaurian kaiju referred to as Titanosaurus, but he doesn't much resemble the real creature, and looks more like some kind of spinosaurid.

1. Entry Time: undetermined
2. Trope Maker: its status as the prototype of the titanosaurian sauropods

A Whale of a Dinosaur: Cetiosaurus *

Which were the biggest animals ever, whales or dinosaurs? Hard question, depends on what criterium you want to use. If you count the length some sauropods could have been even longer than any known whale (blue whale included!), but were still shorter than some modern invertebrates such as the giant ribbonworm Lineus longissimus or some jellyfish (better, their tentacles). If you count the mass, whales probably are still bigger than every dinosaur.

Cetiosaurus, the first sauropod ever described, just means “whale-lizard”, but this is not a mere reference to its size (18 m, a bit shorter than Apatosaurus but with about the same weight); it was literally believed a whale-thing at one point. First found in 1842 in England slightly after Richard Owen coined the word “dinosaur”, its first remains were so incomplete that Owen couldn’t believe such a heavy animal could live on land. Since limb bones were missing, he thought the owner was a non-dinosaurian marine reptile (remember sea-reptiles were already very well-known at the time). When the limb bones were discovered several decades after, the familiar image of an elephantine “reptile” with long neck and tail came to light. Though not a Wastebin-taxon like Megalosaurus and Iguanodon, Cetiosaurus could be seen as their sauropodian equivalent - incidentally, lived just alongside Megalosaurus in Middle Jurassic Europe, but some possible remains traditionally classified as Cetiosaurus have been found in Africa too, more precisely Morocco.

Cetiosaurus has been the archetypical “basal” sauropod in popular dinosaur books, and lived before the Stock Trio, 20/30 million years before them. Among the cetiosaur's primitive traits, it had a more generic skull and teeth than a diplodocid or a brachiosaurid, a tail of middle size, and above all compact vertebrae instead of hollow - cavities in the backbone is a typical feature of more evolved sauropods like Apatosaurus, Diplodocus, Brachiosaurus and Camarasaurus (the latter’s name just meaning "chambered lizard"). These sauropods were discovered in North America just in the period of the cetiosaur’s correct interpretation. Regardless, Cetiosaurus is seen as the most classic sauropod among those found in England.

1. Entry Time: undetermined
2. Trope Maker: its status as "the basal sauropod par excellence"

Volcano Teeth: Vulcanodon *

Discovered in the '70s in Rhodesia (today called Zimbabwe), Vulcanodon's strange name means “volcano tooth” — this is because it was found in sandstone, but its actual teeth are unknown, since its skull hasn't been found yet. The teeth that have given it its the name actually belonged to an unclassified theropod who could have eaten its carcass in life. Vulcanodon lived alongside a small coelophysid named "Syntarsus" (today called Megapnosaurus).

Vulcanodon was very small for a sauropod — 6 m long, less than a plateosaur but still much bigger than a Massospondylus or a "Syntarsus". On the other hand, Barapasaurus ("big-legged lizard", not to be confounded with Barosaurus) was the first known sauropod to have reached the classic huge sauropodian size: 18 m long, like Camarasaurus or Cetiosaurus. It’s also one of the few dinosaurs from India, while the vulcanodont was African and lived alongside the well-known prosauropod Massospondylus, and thus was one of the very first true sauropods appeared on Earth. Some popular sources have quoted it as "the first true sauropod", and some of its bones were actually similar to those of sauropod predecessors.

1. Entry Time: undetermined
2. Trope Maker: its status as "the presumed first sauropod"

Beware My Clubbed Tail: Shunosaurus *

Not every sauropod is either Diplodocoid or Macronarian (Diplodocoid + Macronarian = Neosauropod, "new sauropod"). Many were more primitive than both: Cetiosaurus, Vulcanodon and Mamenchisaurus are three prominent examples. Another basal sauropod like them is Shunosaurus, lit. "lizard from Shu": Shu is one of the old names of the Chinese province of Szechuan, where most Chinese Jurassic dinosaurs come from.

Shunosaurus lived in China at the start of the Late Jurassic, while the much bigger Mamenchisaurus survived some million years later than it. Its first remains were described in the seventies, three decades after the first ones of the mamenchisaur. Even smaller than Saltasaurus (10 m long), weighing as much as an elephant, Shunosaurus was relatively short-necked and with a round head filled with crammed teeth. It had the typical traits of a primitive sauropod... except for its tail. It was very specialized, ending with a bony club on its tail tip like an ankylosaur, surrounded by four short spikes like a stegosaur — in other words, a sauropod with a Thagomizer! Several portraits and museum mounts however show it spike-less, and sometimes even club-less. With its 20 or more skeletons known, Shunosaurus has also been one of the most common sauropods in fossil record. Its tail-club was different than that of an ankylosaur: it was simpler in structure, formed by one single elliptically-shaped piece of bone at the end of the caudal vertebrae, while the "thagomizer" was made of spikes much shorter than stegosaurians.

Shunosaurus appears in one of the short episodes of Dinosaur Revolution. Here, a young shunosaur left alone from its herd becomes intoxicated by a poisonous toadstool it has eaten, and risks to be killed by a pack of large theropods (Sinraptor).

1. Entry Time: 2011
2. Trope Maker: Dinosaur Revolution

Sauropods or Stegosaurs?: Dicraeosaurus & Amargasaurus *

Diplodocus and Apatosaurus had many relatives, not only some real or alleged “biggest dinosaurs ever” (Supersaurus and Maraapunisaurus), but also many other smaller, usually more primitive animals: Dicraeosaurus ("two-forked lizard") has long been one of the most portrayed of them. Found in the Tendaguru deposit in the 1910s, Dicraeosaurus was 13-20 m long but weighed only 6 tons, no more than an elephant. It’s the smallest member of the classic Late Jurassic African Sauropod Trio. The other two have usually been called “Barosaurus” and “Brachiosaurus”, but the former is Tornieria, while the latter is Giraffatitan. One Dicraeosaurus skeleton is mounted next to the more famous Giraffatitan one, in the Berlin Museum. With its short, Apatosaur-like neck and a long, Diplodocus-like tail, Dicraeosaurus could have had a double ridge on its back, but this is not sure. Other less-known sauropods from Tendaguru not related with Dicraeosaurus and found much more recently include Janenschia (named from the discoverer of the site, Werder Janensch) and Tendaguria.

Amargasaurus cazaui was more evolved than Dicraeosaurus: an Early Cretaceous diplodocoid sauropod, also of the Dicraeosaurid family, known from a single but well-preserved skeleton found in 1984 in Argentina in La Amarga Formation (La Amarga = "the bitter one" in Spanish) and officially described in 1991. Unusually for most sauropods, Shunosaurus, Dicraeosaurus, and Amargasaurus have all left skull material. About the same size of the shunosaur, Amargasaurus had a short neck, long whip-like tail, and a Diplodocus-like head like the other dicraeosaurian sauropods. It wasn't especially big either for a sauropod, only about 13 meters and 4 tons (less than an elephant). Like its Chinese clubtailed distant relative it was one of the most well-armed sauropods: it had pairs of neural spines which arose from its neck, rather similar in look to the pairs of bony plates and spikes of some stegosaurians like Kentrosaurus. Scientists have flip-flopped back and forth between reconstructing these spines as being covered in defensive keratin sheathes or supporting an unusual "double sail", but research conducted in 2022 favours the latter.

Interesting, an Amargasaurus-like "sail" was added in the Primeval TV series to a totally different dinosaur, the pachycephalosaurian "Dracorex". Some of the little-stock sauropods listed in this folder (Camarasaurus, Saltasaurus, Amargasaurus) are spottable in one of the sequels of The Land Before Time film marching together with the more famous sauropods, but being unnamed, they act as Genius Bonus. The Pokémon Amaura and Aurorus are also based on this dinosaur.

1. Entry Time: undetermined
2. Trope Maker: their spikes

Other sauropods

Sorry, these ones aren't here. If you're looking for Antarctosaurus, Hypselosaurus, Opisthocoelicaudia, Brachytrachelopan, Isisaurus, Rebbachisaurus, Nigersaurus, Barapasaurus, Pelorosaurus, Euhelopus, Patagosaurus, Omeisaurus, Spinophorosaurus, and others, see here.

Sauropod Predecessors

"Prosauropod" means "before the sauropods". Living in the Triassic or Early Jurassic periods, prosauropods were among the very first dinosaurs to appear, and the first dinosaurs to reach elephant size. Some of them may have been the ancestors of the sauropods. The name Prosauropoda isn't formally used nowadays: members of the group are now referred to as basal sauropodomorphs. Plateosaurus, considered the prototypical "sauropod predecessor", has been one of the most common in the fossil record and one of the largest as well. The much smaller Anchisaurus was the first discovered, in 1818; the similar-looking Thecodontosaurus was one of the first known basal sauropodomorphs as well; the middle-sized Massospondylus has recently revealed excellent remains including nests and hatchlings; while Mussaurus was long only known from nest and hatchlings, until 2013. Riojasaurus is noted to be sauropod-looking and even bigger than Plateosaurus. The 1 m long Eoraptor was originally quoted as "the ancestor of all the other dinosaurs."

The "First Giant": Plateosaurus **

Engelhardt's Broad Lizard

Lived 216-199 million years ago, in the Triassic Period. Plateosaurus is one of the scientifically better-known dinosaurs, and also the most abundant dinosaur in the European fossil record. More than 100 specimens are known, and even a "graveyard" at Trossingen in Southern Germany. Plateosaurus was also one of the first dinosaurs described, even before the word "dinosaur" was invented, but Owen didn’t include Plateosaurus in his new group (its first remains were very fragmentary). When the genus was being classified into Dinosauria, it was first placed in the theropod branch and thought carnivorous; later, it was moved to the prosauropod group. A little-known curiosity is that an older synonym genus of Plateosaurus is just "Dinosaurus".

Three species of Plateosaurus are generally recognized - P. trossingensis, P. gracilis (formerly known as Sellosaurus), and P. longiceps; the first discovered species, P. engelhardti (depicted above), was deemed undiagnostic (i.e. indistinguishable from other dinosaurs) in 2019. As a result, the adult size of this genus was astonishingly variable, from 16ft/4.8m up to 33ft/10m, and its weight ranged from 600 kg to 4 metric tons. At a first glance, Plateosaurus looks like a cross between a diplodocid and a theropod. The general body shape was sauropod-like, with a small head, long neck, sturdy body, long flexible tail, and the typical thumb-claws. The limbs and stance were theropod-like; it was bipedal, walking on hind legs that were slightly folded, rather than pillar-like. The hind feet had distinct digits with a claw on each. The neck was shorter and more flexible than a typical sauropod neck, thanks to its shorter vertebrae, recalling the necks of some theropods. The head was rather theropod-shaped too, but their teeth were small and blunt, apt for grabbing vegetation (without chewing) instead of tearing meat. The closer relationship with sauropods is betrayed by one detail: the hands and feet of the prosauropods had five digits each like sauropods, while true theropods lost the fifth digit both in their hands and their feet (except for the most primitive controversial theropods, like Herrerasaurus, Staurikosaurus, and their relatives, which had five digits on their hands/feet). We still don't know if sauropod predecessors like Plateosaurus had feathers like theropods or dermic spikes like Diplodocus, because skin impressions of these dinosaurs have not been found yet — a strange thing, considering the prosauropods' notable abundance in the fossil record as a whole. Compensating this, the eggs and nests of prosauropods are known, and known early dino footprints have been made by these animals elsewhere.

Science Marches On has been a strong factor within Plateosaurus portrayals. When believed a theropod, it was depicted with a tripod stance like all large bipedal dinosaurs; one example is in Fantasia, where is seen rooting and eating shells. After being classified as a sauropod relative, the plateosaur has usually appeared as a slow quadruped but able to rear up its hindlegs like diplodocids, either to reach higher foliage or for defensive purpose (like in Walking with Dinosaurs). The exclusively bipedal portrait re-emerged only very recently, in the 2000s, thanks to CGI studies, and today scientists believe Plateosaurus kept its body horizontally like theropods, and like them, was capable of relatively rapid bursts of speed if necessary. It may have defended itself with its thumbclaws, like what's believed about another not-related dinosaur, Iguanodon. The "plateo"'s large size could have evolved to avoid predation by the carnivorous dinosaurs, which were still small and gracile at the time; the only predators that were possibly able to defeat the adults were basal archosaurs such as the contemporaneous Teratosaurus.

The two most-known Triassic dinosaurs, Plateosaurus and Coelophysis, are among the most abundant in fossil record but among the least common in pop culture. Plateosaurus appearances in fiction are rare; in documentaries, it is usually shown to emphasize the dinosaurs' "rise to power", a subtrope arisen from Walking with Dinosaurs. Even though some Plateosaurus-looking dinosaurs occasionally crop up in TV (such as Dino, who is officially identified as a "snorkasaurus"), they are more likely highly stylized small sauropods or Mix-and-Match Critter things.

1. Entry Time: 1940
2. Trope Maker: Fantasia

Old Stories: Anchisaurus & Thecodontosaurus *

Despite its scarce fossil record, Anchisaurus is one of the most famed sauropod predecessors, thanks to its historical importance. It was the very first dinosaur ever discovered in North America (1818, six years before Megalosaurus), but was not recognized as a dinosaur at the time; this happened only during the Bone Wars sixty years later, thanks to Othniel Charles Marsh.

An Early Jurassic animal, thus more recent than the prototypical Plateosaurus, Anchisaurus was much smaller: only 9 ft long, about one third of an average plateosaur, and 50 times less heavy. It was one of the most unsauropod-like "prosauropods”, with its rather short neck and limbs: its old quadrupedal portraits made it looking like a long-necked lizard (Anchisaurus means "almost-lizard"). Like all sauropodomorphs, it had large curved thumbclaws for defense. Unlike sauropods, however, Anchisaurus and the other prosauropods could have used them also as tools for grasping or cutting foliage, or for digging the soil in search of roots or insects.

Talking about its modern classification: several scientists now think Anchisaurus, despite its primitive look, was a “near sauropod”, and some in the 2000s have even cited it as "the earliest sauropod". The larger-sized Ammosaurus was believed a relative of Anchisaurus from the same habitat, but it is today generally regarded as a species of Anchisaurus. Same applies with another Early Jurassic North American prosauropod, Yaleosaurus (named after the university). Some alleged Anchisaurus remains were once signalled from Southern Africa from the same epoch of Massospondylus below, but they actually pertain to other kinds of prosauropods.

Anchisaurus appears in one popular documentary of the early 2000s as the chosen prey for Dilophosaurus, who hurts it with exaggeratedly-powerful forelimbs and hand-claws before killing it with its jaws: the anchisaur here is oversized, and actually more similar in proportions to Massospondylus. Some in the past have hyped that Anchisaurus was the real inspirer of the popular pet dinosaur of The Flintstones, Dino, because of its short legs, but there's no confirmation to this.

“Thecodont” ("teeth in sockets") is the traditional catch-all name for the basal non-dinosaurian Triassic archosaurs and archosauromorphs like Euparkeria, phytosaurs, rauisuchians, aetosaurs, and so on. Thus, it could seem that the deceptively-named Thecodontosaurus was one of them: it actually was a true dinosaur, albeit one of the most primitive known. Triassic and European like Plateosaurus, Thecodontosaurus was also one of the first-discovered dinosaurs, in England, and initially was not classified as a dinosaur, just like Anchisaurus. Only 2 m long, Thecodontosaurus antiquus (antiquus = ancient) was the most theropod-like among the classic "prosauropods"; in modern taxonomy, is considered a “really basal sauropodomorph”. Long considered the most archaic "prosauropod", the thecodontosaur has recently lost its record in favor of other dinosaurs — among them, maybe even some putative theropods like Eoraptor and Guaibasaurus. Some Thecodontosauruses have recently been re-classified in other genera (Asylosaurus, Pantydraco). Interestingly, Thecodontosaurus lived much later than other similarly "primitive" prosauropods, on top of being unusually small - qualities that have led some scientists to suggest it was an island dwarf that had survived the rise of more derived prosauropods like Plateosaurus by simply living in an isolated environment.

1. Entry Time: undetermined
2. Trope Maker: their primitiveness and earliness of their discovery

Eggs and Nestlings: Massospondylus *

According to some, Massospondylus ("massive vertebra") is a quite musically-named dinosaur: its full scientific name is Massospondylus carinatus, "keeled massive vertebra". Described in the 19th century from fragmentary African remains, this is today the most scientifically well-known "prosauropod", even more than Plateosaurus itself: almost a hundred individuals of the massospondyl have been discovered so far in Southern Africa, and some doubtful remains from other parts of the world are also known (most of which have been assigned to new genera, such as the North American Sarahsaurus and the Antarctic Glacialisaurus). To date, this is the most abundant dinosaur in the African fossil record, just like the plateosaur is in Europe.

Massospondylus was a “core prosauropod” (like Plateosaurus) according to modern classifications. 4-5 m long and perhaps weighing 300 kg, Massospondylus was middle-sized between Plateosaurus and Anchisaurus. Compared with the plateosaur, it had a smaller head, slimmer neck, nimbler limbs, and shorter trunk. In short, it looked a bit like a Plateosaurus that has undergone a weight-reducing diet (or alternatively a long-legged, long-necked Anchisaurus). Like the latter, in spite of being apparently more primitive and less sauropod-like than Plateosaurus, Massospondylus lived after it, in the Early Jurassic, and was actually one of the last "prosauropods". Because of its slight overbite, one scientist once hypothesized that Massospondylus had a beak on the tip of its lower jaw (an unusual trait for a sauropodomorph, more typical for basal ornithischians), but this has been demonstrated as false.

Massospondylus started to become more common in the fossil record in The '70s, thanks to more than 90 skeletons found in Southern Africa; more recently, in the 2000s, many nests and hatchlings have been discovered in South Africa from this dinosaur, making Massospondylus one of the dinosaurs we know the most about. The lack of teeth among the youngest nestlings has surprised scientists: this is another piece of evidence that dinosaurs practiced active parental care, since these youngsters couldn't feed on their own with their toothless jaws. This discovery closely recalls that of the duck-billed Maiasaura in the 1980s, but with an important difference: the latter's children were all toothy. With their blunt but serrated teeth bordering the whole jaws (typical of prosauropods), adult Massospondylus were probably vegetarian, though they could have also caught some insects occasionally: some gastroliths (gizzard stones) found in the ribcage of some individuals seem to confirm a mainly herbivorous diet. All these discoveries have made Massospondylus a common sight in non-fictional media, earning to it the status of "Rare-Stock" dinosaur.

1. Entry Time: undetermined
2. Trope Maker: its abundance in fossil record and the deep knowledge about its biology

Mickey Mouseosaur and Pseudo-Brontosaur: Mussaurus & Riojasaurus *

Discovered in 1979 in Argentina, the unusually short-named Mussaurus (“mouse reptile”) was a “near sauropod” whose only remains were until 2013 from newborns the size of a house mouse (hence the name), which died just after being hatched. Astonishingly, some thought that these remains were from adults, and many popular books have then reported Mussaurus as a literally mouse-sized dinosaur: some went even further by claiming it was the “smallest dinosaur” ever (or at least the smallest herbivorous one), a true "Mickey Mouseosaur".

Popular portrayals of the mussaur, first inspired by John Sibbick, often depicted the adult form as quadruped animals with the same large head and short neck of the hatchlings. It should be remembered that dinosaurs were not like the distantly-related snakes and lizards, whose youngsters are miniaturized images of the adults; the dinosaurs’ nestlings were more like those of the closely-related birds and crocodilians, both with “childlike”, cuteness-inspiring traits which get lost in adults. Since adult skeletons of Mussaurus were not discovered at the time, obviously we didn’t know how big the adult was: but almost certainly it was at least as large as a human and had the classic small head and long neck of all "prosauropods". Today the adults are also known, and we know now is was medium-sized for a sauropod-ancestor: 6 m long, between Massospondylus and Plateosaurus. Some suspected the 4 m long Coloradisaurus (from Argentina like Mussaurus, not from Colorado!) was in fact the adult form of Mussaurus, but the former is known only from a skull, and was closer to Plateosaurus than to Mussaurus.

Riojasaurus has been, in a sense, the polar opposite of Mussaurus in popular dino-books. Its Spanish-sounding name reveals it also lived in Late Triassic Argentina like the "mouse-reptile" (La Rioja is a northern province of Argentina), but was bigger. More than 10 m long and perhaps heavier than an average elephant, it was one of the largest land animals of the Triassic, even bigger than Plateosaurus itself, only equaled in weight by other "prosauropods" like Yunnanosaurus and the mammal-ancestor Lisowicia. Like other prosauropods, the riojasaur has left an abundant record (more than 30 individuals). Indeed, at a first glance, Riojasaurus resembles more a sauropod, with the same size of many “small” true sauropods like Saltasaurus, Amargasaurus and Shunosaurus, massive limbs and stocky body, and probably walked on four feet like a sauropod, instead of on the two hindfeet like Plateosaurus did (there is controversy about this). However, the structure of its feet with distinct digits and its plateosaur-like skull are typically "prosauropodian". Recent research indicates that Riojasaurus was a “core prosauropod” like Plateosaurus, and not a sauropod-ancestor as previously proposed.

1. Entry Time: undetermined
2. Trope Maker: its allegedly tiny size (Mussaurus); its actually large size (Riojasaurus)

"Dawn Thief": Eoraptor *

Discovered in Argentina in 1993, the same year of the first Jurassic Park film, Eoraptor lunensis means “dawn robber from the Moon Valley” after Valle De La Luna, the formation it was dug out (another astronomical-named dinosaur like Staurikosaurus, the "Southern-Cross lizard"). Its describer, Paul Sereno, first found its skull and believed it was from a basal archosaur; then, the almost-complete and still-articulated skeleton was found, showing it was a true dinosaur, but even earlier than the two traditional "most basal dinosaurs", the herrerasaurians Staurikosaurus and Herrerasaurus, both found in South America between the sixties and the seventies.

Its discovery suddenly seemed to solve the rivalry between them for the “Whoa, the very first dinosaur ever appeared!” title. When it was described, Eoraptor was thought more primitive than both; however newer studies don't always agree with this. 3-4 ft long, not bigger than a Compsognathus, Eoraptor shared with herrerasaurians some skeletal features resembling non-dinosaurian archosaurs; it too, like them, was thought neither saurischian nor ornithischian, but a more basal animal in the middle between true dinosaurs and other dinosauromorphs such as contemporaneous Lagosuchus, also found in South America twenty years before.

Since then, Eoraptor has been perhaps the most celebrated among all the supposed “first dinosaurs”: maybe because was discovered just at the time Jurassic Park came to audiences — and the fact that it received the now-familiar suffix “-raptor” could have done its bit, too. Since then, our “dawn robber” has gained much attention in non-fictional media, also being the object of some degree of sensationalism. Several awesome nicknames were invented, from "the first terror" to "the father of all killer dinosaurs". But the Real Life Eoraptor wasn't so fearsome, really: it was a tiny, gracile dinosaur, which could even become a meal for a hungry Herrerasaurus or even a Staurikosaurus, which were contemporary to it but bigger - Herrerasaurus reached 12 ft of length, Staurikosaurus 7 ft. Research made after the Turn of the Millennium suggested its differentiated teeth were more probably from an omnivorous rather than carnivorous animal. Science Has Marched On Even More in 2011, with studies finding Eoraptor to be an extremely unspecialized sauropod-predecessor, thus closer to Plateosaurus than to Coelophysis. Others however still consider it a proper theropod (in the widest sense).

The study about which dinosaur really deserves the "common ancestor of all dinosaurs" title marches on relentlessly, and now there are many other contenders found and/or described in the 2000s and 2010s other than the most traditionally known. Astonishingly, many of them (but not all) come from South America as well, to the point where South America could be renamed “the cradle of the dinosaur kind” at this point. Nyasasaurus found in Africa in 1956 and initially believed a prosauropod, was described in 2012 as "the first dinosaur" but was actually only a dinosaur-relative. The North American Chindesaurus was possibly a herrerasaurian, the Indian Alwalkeria was possibly non-dinosaurian and/or a fossil chimaera, and the Chinese Lukousaurus has been variably classified from a ceratosaurian to a crocodylomorph. The most basal dinosaur was the common ancestor of Saurischians and Ornithischians, and almost certainly was more similar in anatomy to the former than to the latter: among archosaur groups, saurischians are less derived than ornithischians, at least if you count the structure of the jaws and the pelvis.

1. Entry Time: 1998
2. Trope Maker: The Lost World (film)

Other sauropod predecessors

Sorry, these ones aren't here. If you're looking for Lufengosaurus, Melanorosaurus, Efraasia, Yunnanosaurus, Euskelosaurus, Guaibasaurus, Saturnalia, Glacialisaurus, Issi, and others, see here.

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