Shown Their Work / Prehistoric Planet

With renowned paleontologists like Steve Brusatte, Darren Naish, Alexander Farnsworth, Kiersten Formoso, Michael Habib, Scott Hartman, John R. Hutchinson, Luke Muscutt, Peter Skelton, Robert Spicer, Paul Valdes, and Mark Witton. As well as paleoartists Gabriel Ugueto and David Krentz on the consultants' team this is to be expected.

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Dinosaurs

In general

• Dinosaurs that should have feathers are accurately feathered. The amount on the coelurosaurian theropods also varies greatly, from full coverings of plumage of various sizes in Velociraptor and Mononykus, to sparse amounts in the adult Tyrannosaurus and Tarbosaurus.
• Sauropods and ceratopsians are given a slimmer musculatures, rather than rhino and elephantine like musculatures most media depicts them with.
• Hadrosaurs, ceratopsians, and sauropods are depicted with incredibly textured skin with lots of scale shapes and patterns rather than elephantine leathery wrinkled skin.
• The hands of the theropods present in the program aren't pronated (as they couldn't pronate their arms in real life), but supinated, as they were in truth.
• The emphasis on many young dinosaurs and other reptiles dying before adulthood, with many species producing a large number of young of which many will die (known as r-strategy). The few reptiles that do produce few young, such as Tuarangisaurus, show typical k-strategy adaptations instead. Multiple dinosaur/reptile species are shown to engage in parental care to various degrees as well.^note r-strategy involves producing a lot of offspring, factoring in that most will die, but the sheer number of young ensures a few typically make it to adulthood. Parental care is usually either completely absent or adapted to most young dying over the course of rearing them. K-strategy conversely involves producing few offspring but investing a lot of resources and time in them. Parental care is almost always present and extensive, as fewer offspring means individual losses are more devastating. Evidence suggests that most dinosaurs (and Mesozoic reptiles) were r-strategists, meaning many would indeed meet their end before adulthood. Evidence suggesting parental care has been found in multiple dinosaur species as well, however, including potential creches and communal nests, which given the parental care habits of birds is not far-fetched.
• Most of the dinosaurs and pterosaurs are not shown constantly roaring or shrieking, and are in fact relatively quiet, which more subdued chirping, hissing, and low bellowing in some cases, such as the Carnotaurus calling with low-frequency rumbling or the Dreadnoughtus hissing at each other like geese. Although this is in contrast to nearly all other depictions, it's accurate based on known evidence which suggests most non-avian dinosaurs and pterosaurs had limited vocal repertoires^note this can be seen in extant animals as well, as constantly producing sounds would easily give away their position to either their prey or their predators.
• Since we don't actually know how non-avian dinosaurs drank water, the oasis scene depicts a variety of different plausible drinking styles for the various dinosaurs; the titanosaurs are depicted as suction drinking, hadrosaurs as tongue drinking, and theropods as scoop drinking.
• Several dinosaur species are shown living in creches together as juveniles (specifically the Zalmoxes, Therizinosaurus, and Antarctopelta), which likely represent the fact many dinosaurs were likely independent from a young age, but often associated in sibling groups (or simply other adolescents of similar age) for protection, which is known from extensive fossil evidence of many different dinosaur species.
• In contrast to many dinosaur narrative documentaries, which often mix species from different time periods, the series makes a point to only show animals which are known from the Maastrichtian epoch (with only a very small number of flubs).

Ornithischians

Ankylosaurs

• Ankylosaur armor is correctly depicted as thick skin embedded with osteoderms, as opposed to a bony shell like in stereotypical depictions.
• Club-tailed ankylosaurs are not shown having spikes running along the sides, like in outdated portraits, since only nodosaurs possess those^note This is demonstrated by the Antarctopelta, even though a very recent discovery has shown Antarctopelta was a parankylosaur rather than a nodosaur. Tarchia is the only one that is close to having large spikes running along its sides, but they are not quite the same as a nodosaur's side-spikes due to being placed higher.
• The juvenile Antarctopelta are depicted as traveling together in a creche, a behaviour supported by finds of juvenile Pinacosaurus (another type of ankylosaur) bonebeds, as well as numerous other species of dinosaur suggesting age-divided herding was widespread.

Ceratopsians

• Ceratopsians are depicted with large polygonal scales and large feature scales, they are also given the correct foot anatomy rather than the elephantine feet that they are commonly depicted with.
• Juvenile Triceratops are depicted with horns that curve upward.
• The Triceratops are depicted living in relatively small herds in comparison to Pachyrhinosaurus or hadrosaurs, which likely references studies that indicate Triceratops, unlike some other ceratopsids, likely lived in small family groups at the most.
• Season 2 features one Triceratops individual with enormous brow horns. This is almost certainly based on a Triceratops fossil with unusually giant horns known as "Yoshi's Trike" (MOR 3027). Yoshi's Trike had horns over four feet long, and they would've been even longer in life as they would have been covered in keratin, and might've gotten even larger since the individual was only a subadult.
• Pachyrhinosaurus is depicted with sparse quill-like feathers on its tail and along its back, as the species itself among many ceratopsians is theorized to have possessed.
• The Pachyrhinosaurus in the series are correctly modeled after the Alaskan Pachyrhinosaurus species P. perotorum. Unlike other onscreen depictions which are usually modelled after the earlier and southern-dwelling species P. lakustai.

Hadrosaurids

• Hadrosaurs are correctly depicted as quadrupeds in all their life stages, rather than the outdated interpretation that they started out as bipeds before becoming quadrupeds as they aged. They also have a large hoof on the third finger and a small spade-shaped nail on the second finger, based on the mummified specimen of Edmontosaurus annectens (named "Dakota the Dinomummy")
• All genera have extensive keratinous sheaths to their beak, which mummified specimens have shown. This obscures the paddle-shaped bony core of the beak and makes them look not at all that duck-like as in outdated portrayals showed.
• Edmontosaurus is pointed out as being just as big as Tyrannosaurus, in contrast to many popular portrayals which show it being much smaller, such as Walking with Dinosaurs and When Dinosaurs Roamed America (indeed, some fossils suggest Edmontosaurus actually got slightly larger than Tyrannosaurus).

Pachycephalosaurids

• The Pachycephalosaurus have small, sharp front teeth and engage in partial meat-eating. Younger individuals also have flatter domes, based on a 2021 study that Dracorex may actually be a juvenile Pachycephalosaurus as was long hypothesized. The same study also suggests that Stygimoloch may actually be a species of Pachycephalosaurus (P. spinifer) rather than a juvenile stage, which is reflected by the show's Pachycephalosaurus which have longer spikes on the back of their heads rather than the stubbier ones of P. wyomingensis.
  • The two Pachycephalosaurus males are shown engaging in a mix of head-butting and flank-butting behaviour, and as such the segment manages to illustrate both of the primary hypotheses for how pachycephalosaurs utilized their domed heads in combat.

Saurischians

Abelisaurids

• All featured members of the group (including Carnotaurus, Majungasaurus, and Rajasaurus) are depicted as having small arms with no defined elbow or wrist joints which is accurate to abelisaurs as their arms are vestigial.
• Majungasaurus and Rajasaurus are depicted with osteoderms randomly distributed across their bodies, a trait all abelisaurids were found to have rather than the neat rows shown in older depictions. ^note  The Carnotaurus from S1 should have them randomly assorted as well, but the model was made well before this discovery was made

Sauropods

• The group as a whole is suitably bulky, lacking the shrink-wrapped look many inaccurate depictions give the neck and body.
• Sauropods are depicted as having a single large claw on the forefoot and three on the hindfoot^note While there's some debate as to whether the large thumb claw was lost in derived titanosaurs or if its absence in the fossils is simply an artefact of preservation, the show uses the latter interpretation.
• They also have hardened beak-like mouths as suggested by well-preserved sauropod skulls, instead of fleshy lips or toothy grins as in outdated portrayals. That said, the mouths are shown to be pliable to some degree.
• Dreadnoughtus are depicted engaging in neck-to-neck combat similar to elephant seals, something proposed to occur with other sauropods.
• Sauropods are depicted using their teeth to shear vegetation and swallow it whole rather than chew as sauropods were incapable of chewing.
• Alamosaurus is not only the largest dinosaur in North America but the largest dinosaur so far in the program, at 100 feet long and weighing at 80 tons, rather than being the size of Apatosaurus as in older depictions.

Tyrannosaurids

• While the topic of feathers on T. rex is still debated the juveniles are shown with feathery coats with the adults not having much.
  • And while the narrator doesn't point it out, the juveniles have faint stripes like cougar and boar young.
• The Tarbosaurus has the same sparse coat condition as its American cousin, whereas the very cold climate adapted Nanuqsaurus has a much thicker coat.
• Tyrannosaurus has lips (though it is still debated how prominent they were) and is as bulky as it would have been in real life, rather than the emaciated Prehistoric Monster it's often depicted as. ^note This would have been the natural state of many large-bodied theropods.
  • Even with its bulk, Tyrannosaurus is depicted as a capable swimmer based on its muscular build and weight-saving adaptations^note T. rex didn't have any specific aquatic adaptations, but then neither do a lot of extant swimming amniotes.
• Tarbosaurus is portrayed as potentially quite social when ample food is about, behavior indicated by multiple instances of many individuals in the same location and time without conflict.
  • It also correctly has a slimmer head with a different brow shape than its cousin the Tyrannosaurus, something many media portrayals get wrong by virtually presenting them as a Palette Swap of each other. While subdued, it also has a gular pouch as evidenced by skin impressions.
• When shown beginning to feed on a Triceratops, the Tyrannosaurus starts with the flesh at the neck, likely referencing a study which theorized Tyrannosaurus ate Triceratops first by focusing on the nutrient-rich neck muscles behind the frill.
• Nanuqsaurus is depicted as being fully feathered, a trait it is believed to have in common with many other mid-sized tyrannosaurs ^note  Mid-sized referring to tyrannosaurs in the ballpark of thirty feet long.
  • While there are no known specimens of Nanuqsaurus with feathers yet, they are strongly believed to have had them due to the subarctic environment they lived in, and the presence of feathers in the basal (primitive) tyrannosaur Yutyrannus, which lived in a similar environment and was comparable to Nanuqsaurus in size.
  • Speaking of size, Nanuqsaurus was long thought to be twenty feet long, and is depicted as such in Season 1. However, a 2021 study cast doubt on the original size, and proposed that adult Nanuqsaurus grew thirty feet long instead. In accordance with this study, the adult Nanuqsaurus seen in the Season 2 Ornithomimus hunt segment is about thirty feet long, when using Ornithomimus as a size reference ^note Ornithomimus was 15 feet long in life, and the Nanuqsaurus appears twice as long.
  • Nanuqsaurus is depicted as a pursuit predator, using its stamina to run after prey for long distances. This isn't without precedent, as tyrannosaurs have what is called an "arctometatarsalian condition", which is hypothesized to increase endurance in theropods by evenly spreading impact forces the to the metatarsal bones of the foot.
• The Tyrannosaurus courtship and mating scene uses studies which indicate the snout of tyrannosaurs had many nerve endings and would have engaged in a lot of face-to-face contact (which is known from direct evidence in the form of bite marks), and the sitting posture of the mating dinosaurs is presumed to be the most likely based on comparisons with living birds and reptiles, rather than a standing position.
  • The communication in the scene is also well-formed, with the tyrannosaurs initially assuming low postures and open-mouth bellowing in aggressive confrontation, before the male switches to courtship calling. This consists of closed-mouth bellowing and arching himself to look tall and impressive to the female, while also making himself vulnerable and non-threatening by showing his throat. This is somewhat similar to modern crocodilians that display their throats to show nonaggression.
  • The female Tyrannosaurus in this segment is mentioned as being smaller than the male, making this one of the few documentaries to acknowledge the fact that the oft-mentioned alleged sexual dimorphism of the genus (with females supposedly being larger and bulkier than males) is far from set in stone.
• Qianzhousaurus is accurately given a long skull, with a slim body and legs rather than more bulky builds of large tyrannosaurids.
• The juvenile Tyrannosaurus are depicted as precocial, with their father only there to protect them and guide them to food.
• While there is yet to be any definitive evidence of it in Tarbosaurus and Tyrannosaurus, pack-hunting or communal-hunting has been suggested for both species as far as their hunting strategies are concerned. ^note  In fact evidence of tyrannosaur pack-hunting has been observed in closely related tyrannosaurids thanks to the discovery of mass-burial bonebeds in Alberta, Montana, and Utah, lending credence to the idea that it may have been a trait shared by most of the larger tyrannosaurids
  • Both tyrannosaurs are also shown to be unusually clever in their hunting strategies (which involve rudimentary trap-setting and cooperative tactics). This likely references recent studies which suggest that T. rex and related tyrannosaurids may have been far smarter than we used to think, to the point of potentially being some of the most intelligent non-avian dinosaurs of all.
• The Tyrannosaurus hunting scene also points out that it had superb eyesight, even among all dinosaurs, and fleshy pads under its feet which cushion its heavy footfalls to prevent prey from being able to detect its approach. Both these attributes are known from direct fossil evidence, opposite to what is widely popularized by Jurassic Park.
• it's mentioned in the program that Tyrannosaurus has "six-inch long teeth". In actuality, its teeth got up to twelve inches long, but this still counts as an example of this trope because half of the tooth was root, so of course only six-inches would be visible (or even less depending on how thick the gums were). Many restorations of T. rex inaccurately portray too much of the tooth as being exposed, making its teeth appear unnaturally long.

Maniraptoriforms

In general

• Corythoraptor and dromaeosaurs are accurately depicted with full-body coats of feathers with pennaceous feathers on their arms and tail.
• Corythoraptor males are depicted laying on top of their eggs to protect them from predators and the harsh environment, in exactly the same poses as the fossilized remains of other oviraptorids were found on top of their nests when they died. ^note  Likely having been killed by a collapsing sand dune, heat exhaustion, or other environmental factor than predation
• The show acknowledges enantiornithines exist, and are shown with a bounding flight inferred from their anatomy. They're also notably shown without the fan-shaped tail feathers of modern birds^note while some had fan-shaped tail feathers it is a feature that most lacked. Most enantiornithines instead had elongated rectrices, superficially similar to the long feathers of birds of paradise. While others had elaborate tail displays.
• Troodontids are not referred to as Troodon as the genus name was determined to be dubious and has since been replaced with with the genus Stenonychosaurus. Furthermore, Season 2 correctly and specifically identifies Pectinodon as the troodontid genus native to western North America during the Maastrichtian.

Alvarezsaurs

• The Mononykus is shown feeding on wood-living termites, rather than the giant mound-billing ones which are more famous today, because the latter had not evolved yet and alvarezsaurs consuming the former is considered the most likely.
• Mononykus is depicted with a long flexible tongue which is probable considering it had an advanced hyoid and a toothless tip on the lower jaw.
• While its colouration may be a little on-the-nose, the Mononykus's barn owl-like design likely references a study which indicates alvarezsaurs had a superb hearing on par with modern barn owls^note the study was done on Shuvuuia which Mononykus is closely related to as both are in the mononykini sub group.

Dromaeosaurs

• The dromaeosaurs are shown to walk didactyl with their sickle claw toe held partially on the ground. They are also depicted with very bird-like rounded pupils rather than the reptilian slit pupils they are often depicted with.
• The third episode has a sequence in which Velociraptor hunts some small azharchid pterosaurs. While it may seem unusual that they're not hunting something more expected like a hadrosaur, Protoceratops, or some small mammal, Velociraptor feeding on azhdarchids is known from direct evidence.
• Although dromaeosaurs are depicted as being social, they are more opportunistically gregarious rather than closely knit, somewhat like modern coyotes and birds-of-prey. This is best shown in a hunting sequence with a trio of Velociraptor; when one of them makes a kill, she abandons the other two and doesn't bother sharing.
• The unnamed dromaeosaurs in the fourth episode are depicted with iridescent plumage similar to a magpie or starling. While such colouration on advanced dromaeosaurs is purely speculative, it's not without precedent in earlier members of the clade.

Ornithomimosaurs

• Deinocheirus is given the correct anatomy rather than being a re-skinned therizinosaur. It is also depicted with feathers which is known from other ornithomimids and specimens of Deinocheirus that preserved a pygostyle.
• Ornithomimus is depicted with fully feathered wings and hair-like feathers over the body, as is reported from fossils, and more specifically, the wing feathers are distributed randomly, rather than in neat rows as in modern-type birds, as is known from impressions of more primitive winged coelurosaurs.

Marine Reptiles

In general

• Plesiosaurs and mosasaurs are both depicted with tail flukes and Plesiosaurs are shown with ample amounts of blubber to stave off the cold water.^note While Mosasaurs in the show are also depicted with blubber, paleontologists doubt that they would've had it due to their relatively quick evolution to marine life..

Mosasaurs

• Mosasaurus is depicted with its teeth sunken into its gums like modern-day lizards, as well as with pebbly scaly skin that is being shed in flakes, a prominent forked tongue, and palatal teeth being clearly visible in several shots.

Plesiosaurs

• Plesiosaurs are depicted taking care of their young like whales; bonebeds of both adult and juvenile plesiosaurs have been found which suggests this, and the fact that they gave birth to only a few if not single babies at a time (known in biology as K-Selected species) that were fairly large is consistent with creatures that engage in complex parental care. The enormous size of the plesiosaur baby in relation to the size of its parent is also referenced.
• Plesiosaurs are shown sticking their necks above water. However, they do it in a vertical position similar to whales when they spy-hop, rather than the swan-like pose in outdated portraits and classic Loch Ness Monster portrayals.

Pterosaurs

In general

• Pterosaurs are depicted with pycnofibers, wings fold in from the back as a result of their hands rotating backward, and walking plantigrade.
• Pterosaurs are depicted taking off by vaulting with their wings, rather than by jumping with their hind legs like most other media depictions.
• Despite Darren Naish's notorious questioning of rounded wing tips in pterosaurs, nyctosaurids at least still have them in flight (not on the ground where they are hyper-retracted. This is supported by studies on aerodynamics and phalange curvature.

Pteranodontians

• Nyctosaurids are depicted without wing-claws, a distinctive trait among the family.
• Barbaridactylus are depicted as sexually dimorphic with the males being around twice the size of the females and females lacking crests^note dimorphism isn't known from Barbaridactylus itself but is known in other nyctosaurids and their close relatives◊ the pteranodontids.
• The baby Alcione are depicted as living inland for the first few years of their lives, referencing studies that indicate young pterosaurs of some species likely lived in wooded, terrestrial environments before growing into seagoing adults. They're also depicted as flight-capable and independent almost immediately from hatching, and it's mentioned that their eggs' shells are leathery.

Azhdarchids

• Azhdarchids (such as the Phosphatodraco from the first episode) are portrayed as terrestrial predators that hunt small creatures on the ground, rather than flying to catch them like the Barbaridactylus does. The Quetzalcoatlus in "Freshwater" is also depicted as a very competent animal on land able to run and chase other animals despite its aerial adaptations.
• Azhdarchids are also depicted with "forward-swept" wings in flight, as is suggested by recent studies would have been a necessary position for such front-heavy animals to keep themselves balanced in the air.
• The Hatzegopteryx is presented as a more robust azhdarchid with a shorter neck than other species presented, instead of being basically a European Palette Swap of Quetzalcoatlus as used to be believed.
• Hatzegopteryx was indeed an apex predator of Hateg Island and the European archipelago and was quite capable of chasing dinosaurs down even when hunting on land.

Synapsids

Allotheria

• "Ice Worlds" features Cimolodon (albeit very briefly and unidentified). Contrary to historical depictions of multituberculates as sprawling mammals, this one has fully erect and digitigrade limbs, in line with a few recent studies.

Pseudosuchians

Notosuchians

• Simosuchus is depicted as a burrowing animal, which is supported by multiple features of the crocodylomorph's anatomy (namely its robust limbs and short, boxy snout, and as shown in the episode a burrowing lifestyle would serve as its most obvious defense mechanism against large dinosaurian predators).
• Simosuchus is also depicted as a social animal that lives in colonies like a prairie dog. This is likely based on circumstantial evidence of notosuchian nesting colonies and the fact they laid far fewer eggs than other crocodilians, strongly suggesting they had more complex parental care and social behaviour.

Amphibians

Anura

• Beelzebufo isn't depicted as simply being a beefed-up horned frog (Ceratophrys) as is present in nearly all other portrayals, since Beelzebufo probably is not as closely related to this genus as was initially believed.
• It's also correctly depicted with rugose armoured skin (similar to the modern horned frogs, its upper body was covered in bony plates), and very noticeably has sharp teeth in its upper jaw (frogs have teeth in the upper jaw, but, with only one known exception, none in the lower jaw).

Fish

Actinopterygii

• Non-reptilian marine life is shown to be the actual mix between still-existing taxa and extinct ones. Notably, the small cleaner fish surprised by the mosasaur's arrival is a pycnodont fish, a mostly Mesozoic fish genus.
• Xiphactinus was not only a voracious predatory marine fish, like many of the larger ray-finned fishes (including modern species) it possesses the necessary adaptations for cranial kinesis, which allows it to suction feed on smaller prey items such as the lantern fish in "Oceans".

Invertebrates

Cephalopods

• It is highly unclear if ammonites really had beaks, as they don't fossilize well. Season 2 shows some of the species being filter feeders and others as predators who hunted fish.
• Ammonites are also shown to have soft bodies resembling that of squid, rather than the nautilus^note to which they are only distantly related or even slug-like appearances they've been given in the past.
• Unlike many other prehistoric programs, this show acknowledges that ammonites with different shell shapes exist, not just nautilus ones.

Insects

• The earliest modern-looking termites show up in the fossil record during the earliest Cretaceous so their inclusion in the show is not out of place. It also shows them as being wood-living termites, as mound-building termites are not known to have appeared until after non-avian dinosaurs became extinct.
• Bees were around in the Maastrichtian as they first evolved during the mid Cretaceous due to playing a large role in the co-evolution of angiosperms.
• Despite not having honeybee fossils from the Cretaceous, molecular evidence shows that they existed back then. Their sister taxon, the stingless bees, also existed during the Maastrichtian, phylogenetically supporting this. Additionally both stingless and honeybees are social and produce honey making the inclusion of dinosaurs eating honey not out of place.

Plants

Angiosperms

• The show goes out of its way to avoid filming grass in larger quantities than isolated patches here and there, as grass had only started evolving during the Cretaceous and would not be widespread until the Miocene. Instead the show features ferns and horsetails in the diet of ground browsing herbivores. The only prominent grass-like plant in the show is the reed in the Deinocheirus segment that takes place in Central Asia, which is not far from China where some of the earliest grass fossils were found.

Gymnosperms

• The show alludes to the hypothesis that ginkgos relied on some sort of now extinct frugivore to spread their seeds (since no known animal, aside from humans, naturally spreads its seeds today). In this case, Corythoraptor.