Science Marches On / Dinosaur Planet

While Dinosaur Planet was very up-to-date (some might even say ahead of its time) with its dinosaur portrayals, modern paleontology has made more then a few discoveries since its debut:

General Issues

• Despite being one of the main points of pride for the show, many of the fully-feathered maniraptoran designs show their age:
  • Dromaeosaurs ("raptors"), troodontids, and oviraptorosaurs should all have actual clawed wings, with the wing itself extending off the second finger just as in modern birds, and the second and third fingers may have been joined by skin. The Oviraptor, Velociraptor, and troodontids are the best in this regard, given half wings (though still not properly feathered) that extend as far down as the wrist, while the dromaeosaurs in "Pod's Travels" lack any attempt at wings and just have "feather sleeves". Additionally, while none of them completely pronate their hands, they still fold them in a semi-pronated posture that is contradictory to what we now know about wing anatomy.
  • Many of the designs have fairly reduced (if not completely absent) tail fans that are limited to just the end of the tail, but recent finds show that such features actually ran along at least half the length of the tail in many, if not most, species.
  • The feathers covering the bodies of most of the designs appear to be simple filamentous integument (like downy feathers on baby birds) when in fact many of them should have an outer covering of more structurally complex feathers, giving them a smoother and less fuzzy appearance. The presumed feather type also affects the coloration; some colors like bright blues and greens and iridescent effects are a result of the structure of complex feathers and thus usually cannot be produced by more hairlike simple feathers. (See here and here for guides on this.)
• Virtually all of the dinosaurs have pronated (forward-facing) forelimbs, or at least occasionally hold them in a pronated position. With some exceptions, this is anatomically impossible for dinosaurs to have actually done. Instead, they would have been held sideways like they were about to clap.
• Confusingly, the big ornithopods (Rhabdodon and Maiasaura) are shown galloping on all fours, even though When Dinosaurs Roamed America accurately showed hadrosaurs as facultative bipeds who run on two legs.
• Many of the dinosaurs vocalizations use a combination of stock mammalian sound effects like elephant squeals and big cat roars and growls, but recent studies of their vocal abilities (largely via inferring the type of vocal chords by phylogenetic bracketing) has suggested that many dinosaurs likely had a much more limited and subtle repertoire comprising of closed-mouth hisses, booms, and hoots.

"White Tip's Journey"

• The episode follows the traditional interpretation regarding the age of the Djadochta Formation, which was commonly cited as Santonian-early Campanian (85-80 mya), but later studies determined that it actually dates to the latest Campanian (75-72 mya).
• A couple things on Velociraptor:
  • Despite being the crux of the episode's plot, there's no evidence that Velociraptor actually lived and hunted in packs, and its desert habitat might have in fact made such a lifestyle disadvantageous. Jurassic Park may have popularized this portrayal, but it's currently totally speculative. In fact, there's little known evidence to strongly suggest pack life for pretty much any dromaeosaur, save for a set of trackways showing multiple animals jogging in the same direction. Conversely, there is ample evidence of aggressive and even fatal interactions between dromaeosaurs, Velociraptor included, so the offscreen massacre of White Tip's pack by another group isn't unlikely even if they were occasionally gregarious animals.
  • Male dromaeosaurs were probably the ones responsible for brooding nests (so Blue Brow should've at least been a more active father), and young were likely capable of foraging on their own early on instead of relying on their parents for food. A study on some troodontid nests appeared to confirm this, though later research showed the sex of the individuals guarding the nests is ambiguous. But since the closest living relatives of these animals (ratites) brood their nests this way, it's hardly unlikely that they didn't do it too.
  • The narration uses an outdated 100 lb (45 kg) figure for White Tip's weight, but more modern studies of dinosaur mass give a 33-43 lb (15-19 kg) range for her species — about a third of the initial estimate.
  • The model has some 24 teeth in the upper left row alone, while actual Velociraptor have about 16-18 teeth per row.
  • The crests in front of the eyes are actually the front end of a brow ridge that would run over the entire eye like in eagles, giving a permanently angry look. Distortion and decomposition of the fossil skull likely led to the original crest interpretation.
  • While not technically incorrect, the narration's description of White Tip's eggs' incubation period would've had more accurate connotations if it were described as taking months rather than weeks.
• Prenocephale should have a few updates, itself:
  • Prenocephale hails from the Maastrichtian-aged Nemegt Formation, which overlies the Campanian-aged Djadochta Formation, so it would not have been a contemporary of Velociraptor, Protoceratops and Oviraptor/Citipati, though related pachycephalosaurs could have existed at Djadochta.
  • Rather than being a desert dweller, this animal seems to have been more partial to upland forests rather than open sand dunes.
  • The domes on their heads would likely be covered in a keratin pad rather than skin and scales as shown.
  • The finding that pachycephalosaurs were poorly equipped for head-on collisions (à la bighorn sheep) yet still show signs of cranial injury due to repeated usage has led to the idea that they were using their heads more like wrecking balls, swinging into an opponent's body in a similar fashion to giraffes.
• Oviraptor is rightly shown to be a nurturing parent, with mothers nesting nearby each other. However, newer studies of Asian oviraptorid nests indicate that they were actually communal nesters, with multiple females sharing a single nest that was brooded by a single individual (likely the father).
  • Additionally, the classification of the show's depiction of Oviraptor has been very convoluted. It was based on two tall-crested oviraptorid specimens from Djadochta (informally named "'Ronaldoraptor") which were once attributed to Oviraptor, as the genus was historically a dumping ground for various oviraptorosaur fossils from Late Cretaceous Asia, but was later relegated to just the holotype specimen. Meanwhile, the two tall-crested specimens were subsequently attributed to Citipati (named in 2001), which is known from numerous specimens originally attributed to Oviraptor but are twice the size of the Oviraptor holotype (which is similar in size to Velociraptor). Late though, it was determined that the tall-crested oviraptorid might not belong to Citipati either (who is otherwise known for sporting a small head-crest) and likely represent a wholly new type of oviraptorid that has yet to be named.

"Pod's Travels"

• Pyroraptor is (confusingly, given Velociraptor's portrayal) shown with a heavily scaled lizard-like face as opposed to the skin and/or feather-covered face that dromaeosaurs had, and also lacks wings of any sort. Additionally, Pod's uniformly bright red coloration is unlikely given his reconstruction's presumed feather type (filamentous integument rather than the complex feathers he should have) and diet.
• Some subsequent phylogenetic studies have recovered Pyroraptor as an unenlagiine (which were poorly known at the time), who were a branch of the dromaeosaur family (or a related family of paravians) native to the Southern Hemisphere and characterized by very elongated snouts and being better adapted for running◊ than their northern brethren. Give how the sympatric abelisaurs were also endemic to the Southern Hemisphere with the exception of southern Europe, it’s possible that unenlagiines made the same northward migration, but due to the paucity of the Pyroraptor fossils, it’s exact phylogenetic position remains controversial.
• A pack of dwarf dromaeosaurs is shown successfully taking down prey several times their own size, an exaggerated and commonly-portrayed behavior that has largely fallen out of favor since there's little good evidence for it and no modern tetrapods really routinely behave this way. Whether hunting alone or in groups they probably would have taken prey close to their own body size. Their green feathers are also unlikely given their intended feather type.
• The creatures referred to as Iguanodon are actually rhabdodontids, a more basal ("primitive") group of dinosaurs than Iguanodon itself. This particular example highlights just how much of a wastebasket taxon Iguanodon used to be, with some older sources claiming that it survived into the Late Cretaceous, specifically referring to the European rhabdodontids. Unlike their depictions, rhabdodontids were bipedal and lacked the thumb spike characteristic of Iguanodon and similar dinosaurs.
• While its fragmentary remains are still considered attributable to an abelisaur, Tarascosaurus is generally considered a nomen dubium nowadays. Additionally, estimates of its "actual" size indicate it being closer in size to the dwarf species on Hateg Island.
  • Though its portrayal in the episode has become vindicated in 2013 with the discovery of Arcovenator escotae, a large-sized abelisaurid who was a contemporary of Pyroraptor and Rhabdodon (as they all hail from the Argiles Rutilantes Formation).
• Though their presence on Hateg island isn't impossible, given the strong biogeographic links between it and the mainland (the Ibero-Armorican island) and the presence of possible non-maniraptoran teeth on Hateg (like "Megalosaurus hungaricus"), one of the main inspirations for the dwarf abelisaurs was a supposed distal femur (FGGUB R.351) attributed to a small abelisaurid, but only two years after the series aired, it was reinterpreted as the distal metatarsal of a hadrosauroid.
• There are a number of problems with the plesiosaur:
  • Plesiosaurs were generally covered in small smooth scales, likely lacking osteoderms entirely. They also had small vertical fins on their tail ends.
  • The necks of plesiosaurs (particularly elasmosaurids, which this seems to represent) likely couldn't bend as much as depicted when it grabs Pod's sister, let alone be lifted out of the water Loch Ness style.
  • It's also oversized relative to more modern estimates of elasmosaurid length, stated to be 50 feet (15 m) long while the largest modern estimates reach about 40 feet (12 m).
  • Snatching up and devouring a land animal pushes it into full-on Sea Monster territory and is full-blown Artistic License – Paleontology. More extensive research on plesiosaur dentition shows they were very specialized to hunt fish and cephalopods, though how they did this isn't entirely clear. In any case, their conical teeth would've been very inefficient at tearing a struggling theropod into chunks that could be swallowed by their thin necks. A mosasaur, which are well known from Late Cretaceous Europe, including the giant Mosasaurus, would have been a better choice.
• The Troodon are based on remains currently assigned to Elopteryx and/or Bradycneme, both of which are fragmentary^note to the point that the former is a nomen dubium and may not even be troodontid in the first place.
• The presence of the American Ichthyornis in this episode was likely inspired by reports of a similar ichthyornithean bird from the Late Cretaceous of Belgium during the early 2000s, but in 2022, this animal was properly described as a distinct genus, Janavis finalidens, which is twice as big as Ichthyornis. Fossils attributed to Ichthyornis were also known from Russia and Uzbekistan, but they are no longer attributed to the genus, with the material from Uzbekistan being reinterpreted as an enantiornithine.
• Pod wouldn't have been at the top of Hateg island's food chain, the much larger Hatzegopteryx (a much bulkier cousin of Quetzalcoatlus) would have been, and it would have been all willing to snack on Pod himself if it got the chance, since it also likely preyed on the dwarf sauropods. Hatzegopteryx was named in 2002 (while the series would have been in production) and the idea that azhdarchids were ground-stalking predators instead of vulture-like scavengers or typical piscivorous pterosaurs (as traditionally thought) didn't take off until 2008.

"Alpha's Egg"

• Saltasaurus loricatus lived during the early Maastrichtian (circa 70 mya), a good 10 million years before the setting of this episode. However, an older species called Saltasaurus australis was known to have coexisted with Aucasaurus at the Anacleto Formation... but nowadays, it’s more commonly known as Neuquensaurus australis. If the latter was the inspiration, Alpha and her kin would retroactively be recognized as Neuquensaurus.
• A lot of the Anachronism Stew in the episode can also be explained by the fact the Anacleto Formation (from where Aucasaurus, Neuquensaurus and Aerosteon, the latter being the probable inspiration for the carcharodontosaurs, are known) and the Bajo de la Carpa Formation (from where Alvarezsaurus and Notosuchus are known) used to be considered the same fossil formation (called the Río Colorado Formation).
• We now know Aucasaurus had even less developed arms, and lacked claws altogether.
• The episode puts Aucasaurus at a ton, but later estimates put it at a relatively smaller size of around 1,500 pounds.
• A Carcharodontosaur drags a Saltasaurus carcass, but a recent study on the carcass-moving capabilities of large theropods — specifically on Carcharodontosaurus itself — shows that it wouldn't have been capable of doing this with such a large prey item, considering that Saltasaurus is estimated to weigh about three times the maximum dragging capacity of the theropod.
• The idea of carcharodontosaurids (the family that includes all the giant taxa like Giganotosaurus and Carcharodontosaurus itself) still existing in Patagonia by the early Campanian is not supported by current evidence, as the last of the Patagonian giants (Mapusaurus) died out 93 million years ago and they were replaced by abelisaurids and megaraptorans (who previously served as mesocarnivores to the apex predator carcharodontosaurids), with the youngest carcharodontosaurid fossils to date being known from Asia, where they lasted until the Turonian (circa 90 mya). Some very fragmentary fossils from Maastrichtian rocks (72-66 mya) in Brazil were previously considered as possibly belonging to late-surviving carcharodontosaurids, but further examination showed them to be abelisaurid fossils.
  • The carcharodontosaurs featured in the episode may specifically be based on Aerosteon, a megaraptoran once considered a late-surviving carcharodontosaur that was contemporary with Aucasaurus. It was also initially thought to be much larger, estimated at around 30-35 feet in length, close to the size of the carcharodontosaurs depicted in the show, whereas current estimates put it closer to 20-25 feet in length (though the holotype might not be fully grown, due a lack of fusion in certain bones).
• The Saltasaurus are depicted as reaching full size in under 13 years, but this estimate for sauropod growth rate was come under analysis for the fact it greatly exceeds the growth rate of comparable precocial birds and mammals when scaled up to the same size. More recent estimates suggest it could take anywhere from 20 to 45 years for a titanosaur to reach adulthood (still exceptionally fast).

"Little Das' Hunt"

• The episode is set in the Two Medicine Formation of Montana, 75 million years ago. While most of the fauna presented are at least based on remains from the formation, the formation itself covers a nearly 10-million year stretch of time and subsequent studies of its stratigraphy show that not all of the animals there actually coexisted due to being spread out across that time range. Daspletosaurus and Einiosaurus are the only two genera to come from rocks of a similar enough age to justify their inclusion, while Maiasaura, Orodomeus, and Troodon are from over a million years earlier. Prosaurolophus and Saurornitholestes would've been more contemporary replacements for Maiasaura and Troodon.
• Orodromeus is generally okay, although modern depictions often give the animal a speculative feathery coat akin (and due) to Kulindadromeus. However, the latter is a very basal ornithischian and only distantly related to Orodromeus, while a preserved leg of the closely related Thescelosaurus is covered in scales, with no trace of feathers. It also has teeth protruding from its beak, although teeth and beaks don't develop together in that fashion. In addition, close relatives of Orodromeus are now known to be burrowers, and Orodromeus itself has features that lend itself to such a lifestyle.
• Pretty much everything about Quetzalcoatlus (and whatever else the show by extension implies about pterosaurs as a whole) is extremely outdated. It’s especially odd, given how its counterpart from When Dinosaurs Roamed America was fairly accurate for its time.
  • Its inclusion in the episode is inaccurate, since the animal(s) that the name refers to lived over 5 million years after the setting. This was due to the fact that fossils of large-sized azhdarchids from both Two Medicine and the contemporary Dinosaur Park Formation were historically attributed to Quetzalcoatlus, though that sentiment was already waning by the time this series aired. In 2019, the Dinosaur Park specimens were recognized as a new species, Cryodrakon boreas. Whether the large Two Medicine azhdarchid represents further material of Cryodrakon or a close relative remains to be seen.
  • Appearance-wise, the animal is shown with a scaly/leathery hide and the proportions of a pteranodontid (short neck, small head, long broad wings) with a squat posture on the ground. However, all pterosaurs had a covering of filamentous integument called pycnofibers^note that are probably homologous to dinosaur feathers across their bodies^note this was actually already known since at least the 1970s if not nearly a century earlier, but pop culture was very slow to adapt for thermoregulatory purposes (refuting the narration-implied notion that they were ectothermic ("cold blooded")), and azhdarchids like Quetzalcoatlus generally had proportionately long necks and large heads that contrasted with their proportionately short wings, as well as a more upright posture that would allow for an efficient gait.
  • Rather than being a clifftop-dwelling piscivore that couldn't take off under its own power, Quetzalcoatlus was likely a terrestrial forager that moved through open areas and targeted small prey, using its powerful forelimbs to vault itself into the air when it needed to take off.
  • Pterosaurs were probably not outcompeted by birds, as the two coexisted for 85 million years with seemingly little noticeable effect on each other's species diversity, even into the Late Cretaceous, which still featured a decent variety of pterosaur species of different sizes and ecological niches.
  • Young pterosaurs, unlike what the show implies, seem to have been highly precocial to the point that they could fly within minutes of hatching. The majority of nests and eggs that have been found also appear to have been buried.
• The theropod referred to as Troodon is likely a completely different taxon. To elaborate, Troodon formosus was originally a tooth taxon described from the Judith River Formation in 1856, while actual skeletal material of troodontids that were subsequently synonymized with Troodon came from the Dinosaur Park and Two Medicine Formation respectively many decades later (Troodon was initially thought to be a Pachycephalosaurus). However, a 2017 study deemed Troodon a dubious taxon since it was first described from teeth (which are considered undiagnostic on a generic level) and in the wake of it, most of the Dinosaur Park specimens reverted back to their original name (Stenonychosaurus inequalis), while the biggest ones were redescribed as a new species (Latenivenatrix mcmasterae). The Two Medicine troodontids, however, still await proper revaluation, so the jury is still out on whether they represent further material of Stenonychosaurus or possibly a different taxon (much like Two Medicine’s azhdarchid).
• The Maiasaura models lack the small spiky ridge/crest between their eyes that they should have. Additionally, they're implied to only have grown to about 20 feet (6 m) in length when in fact the largest known specimens measure almost 30 feet (9 m).
• Both Das and the young T. rex at the end are just downscaled versions of their adult counterparts. We now know that the ontogeny of tyrannosaurids like Tyrannosaurus and Daspletosaurus was far more complex, as younger animals would have looked drastically different from adults, with elongated snouts, lankier bodies, and very long legs, which made them speedy pursuit predators whiles adults were more sluggish and would have had to ambush their prey. The episode does acknowledge that Das is faster than his older sisters and mother but that is not reflected in his anatomy.
• Daspletosaurus is depicted as heavily scaled, even though tyrannosaurs actually had very small scales across most of the body that wouldn't have been visible from more than a few feet away.
  • The official website describes this species of Daspletosaurus as D. torosus when it is in a fact a separate, later species called D. horneri. Of course, D. horneri was only described in 2017, long after the series aired.
• Einiosaurus is shown with four fingers contacting the ground, when ceratopsians actually only walked on their inner three digits. Its forefeet are also much too elephantine, with a large footpad behind the digits that didn't actually exist in any ceratopsian, or any quadrupedal dinosaur for that matter.
• The final scene of the episode flash-forwards to the Hell Creek Formation, 68 million years ago. Perhaps this is due more to budget constraints than research work, but the environment is depicted as being identically dry savannah uplands to that of the Two Medicine Formation when in fact Hell Creek was a much more perennially lush environment, being a forested coastal floodplain.
  • Edmontosaurus annectens is featured briefly, presented as a descendant of Maiasaura. However, there isn't much evidence to support such a relationship between these animals, and implying it is generally avoided in paleontology as direct "missing link" or "ancestor" fossils are vanishingly rare and reflect a misunderstanding of how evolution works. Most phylogenetic studies recover Edmontosaurus as closely allied with numerous Asian hadrosaur species, including a sister taxon relationship with the nearly identical Chinese hadrosaur Shantungosaurus, suggesting its ancestors actually immigrated to North America.
    • A few recently discovered fossils also suggest Edmontosaurus grew much larger than the length of "forty feet" given in the episode, giving measurements on par with the fifty-foot Shantungosaurus, possibly making it one of the largest non-sauropod dinosaurs (although this size would've been exceptionally rare).
  • Tyrannosaurus rex is shown and mentioned as a direct descendant of Daspletosaurus, a fairly popular hypothesis that was recently been called into question with more phylogenetic and biogeographical studies of the tyrannosaur family, and its now understood Tyrannosaurus is part of a tribe originating in Asia, and its closest relatives were Tarbosaurus and Zhuchentyrannus. And then this was challenged by discoveries in the early 2020s which indicate that Tyrannosaurus does actually originate from North America, but evolved in what is now New Mexico.