List of Scientific Errors and Speculations

Prehistoric Planet is one of the most accurate paleodocumentaries to date. However, this does not make it free from errors, nor does it mean that everything in it is completely proven, though some of these speculations are not necessarily wrong, some are even logical, just lacking in proof. Some of the errors seen here may also be due to new discoveries made during or after the episodes are released, hence, some were not necessarily wrong during the time when Prehistoric Planet was being made or released, just simply rendered outdated by new data.

It should be noted that not every event and depiction without proof would be presented here (e.g. most skin patterns, most sounds, the way in which *Simosuchus* kept a *Majungasaurus* at bay, or specific interactions between species like *Barsboldia* and *Tarbosaurus*, *Beelzebufo* and *Rapetosaurus*, *Quetzalcoatlus* and *T. rex*, etc.), only the ones that are not immediately understandable as being minor, plausible, or logical enough to not need defending or further clarification to clear up confusion.

## General

### Azhdarchids

* The azhdarchid pterosaurs of Prehistoric Planet have, at times, been depicted outside of the areas they are known to have lived in.
	+ In the case of *Quetzalcoatlus*, which flew from North America to lay eggs in the swamp forests of South Africa, there is no evidence suggesting the presence of azhdarchids in the area (though there have been azhdarchids found in the northern, eastern, and western regions of Africa). However, given how *Quetzalcoatlus* is capable of covering 13,000 - 19,000 kilometers (8,000 - 12,000 miles) in 7 - 10 days, this speculative scenario is not entirely implausible.
	+ In the case of *Hatzegopteryx*, while it is only known from Hațeg Island, the remains of similarly-large azhdarchids found across Europe (which may either be *Hatzegopteryx* itself, or closely-related species) indicate that *Hatzegopteryx* is indeed an "island-hopping pterosaur", justifying the scenario shown in the second segment of Islands, which depicts several of them visiting the Liburnia Formation in Trieste, Italy to hunt prey like Tethyshadros.
		- While this is more plausible due to the significantly shorter distance traveled from Romania to Italy, conversely, flight does not necessarily mean that an animal would travel even short distances to hunt on another island (for example, the now-extinct Haast's Eagles, also flying apex predators enlarged by insular gigantism, never attempted to visit or colonize the North Island of New Zealand, only staying on the South Island, though they did visit Stewart's Island further down south).
* While the full extent of sexual dimorphism is unknown in azhdarchids, sexual dimorphism is apparent in many other pterosaurs, and Dr. Darren Naish, lead consultant of Prehistoric Planet, brings up how, not only is sexual dimorphism the logical conclusion for azhdarchoids (the group that includes azhdarchids), but also that melanosomes in azhdarchoid crests serve as further proof of their use as display structures.
	+ The old male *Hatzegopteryx* in the sixth segment of Islands is depicted with a special coloration just for the breeding season, much like modern-day reptiles and birds.
	+ The other azhdarchids of Prehistoric Planet are only shown to have one form with duller colors and less-prominent crests (*Phosphatodraco* has a low ridge running down its head much like female *Hatzegopteryx*, while *Quetzalcoatlus* and the Gurilin Tsav azhdarchid have a very small, rectangular crest). It is unknown if this is meant to show that the individuals of these species are females (which is the case for the two *Quetzalcoatlus* that appeared in the fourth segment of Freshwater), or that the other azhdarchids are not sexually dimorphic like *Hatzegopteryx*.

### Dromaeosaurids

* While dromaeosaurs are often portrayed in popular culture as working in tightly-knit packs akin to wolves, it was more likely that dromaeosaurs temporarily hunted together in loose packs, engaging in situational pack-hunting similar to that of coyotes and modern birds of prey (which, as members of the Paraves clade, are technically dinosaurs and therefore modern-day relatives of dromaeosaurs). Evidence of dromaeosaurs living (or at least moving) together comes in the form of a trackway discovered in Shandong, China in 2007, footprints left behind by six *Achillobator*-sized dromaeosaurs traveling together down a shoreline (though it is also possible that these tracks were left by separate individuals that just so happened to travel down the same path at different times). Current ideas suggest that, when hunting as pack, they would converge on their prey, mobbing it much like Komodo Dragons do today, before going their separate ways.
	+ In the first segment of Freshwater, three *Velociraptors* are shown grouping up to hunt pterosaurs, but they still prefer to attack individually, secure their own prey, and depart once they got what they needed.
	+ In the first segment of Ice Worlds, the dromaeosaurs are shown usually hunting alone, though individuals would greet each other like old friends and cooperate when the opportunity to hunt greater prey arises, with three of the dromaeosaurs spreading panic through a herd of *Edmontosaurus*, causing them to frantically cross a river, which in turn results in some individuals getting drowned and washed up on the river's banks.
	+ In the second segment of Badlands, yet another case of justified pack-hunting behavior is depicted in the form of a pair of *Velociraptors* raising hatchlings together, with a female *Velociraptor* chasing a *Prenocephale* up a ledge where her mate can ambush the target and kick it off the cliff to its demise, securing a meal for both of them and their chicks.
* The two *Pyroraptor* chicks in the third segment of Oceans look identical to the pair of juvenile *Kuru kulla* seen in the third segment of Badlands. This is not entirely implausible, since the young of closely-related species tend to resemble each other, with both the *Pyroraptor* and *Kuru kulla* chicks looking similar (but not identical) to the *Velociraptor* chicks seen in the second segment of Badlands. This can also be observed in the modern-day relatives of dromaeosaurs, birds, where different genera can at times seem very similar - if not almost indistinguishable - even as adults.

#### "*Velociraptor*"

* Both known species of *Velociraptor*, *V. mongoliensis* and *V. osmolskae* lived 75 - 71 million years ago, during the Campanian stage of the Late Cretaceous. *V. mongoliensis*, the more known species, was found in the Djadochta Formation, set in what would become the modern-day Gobi Desert in Mongolia, while *V. osmolskae* was found in the nearby Bayan Mandahu Formation in Inner Mongolia, China.
	+ Of note, however, is that the animal seen in Prehistoric Planet isn't confirmed to be *Velociraptor*, rather, it is a species of indeterminate velociraptorine found in some areas of east Asia, referred to as "*Velociraptor*" for simplicity's sake.
		- It is possible that this unidentified animal may indeed be a new species of *Velociraptor*, however, and if that is the case, it would indicate *Velociraptor's* presence in the Nemegt Formation, 70 million years ago, during the Maastrichtian stage of the Late Cretaceous Period.
	+ There is the belief that the indeterminate velociraptorine of Prehistoric Planet may be *Adasaurus* (Evil Lizard), a close relative (and perhaps even descendant) of *Velociraptor* that did live in the Nemegt Formation.
		- However, it should be noted that *Adasaurus* is noticeably bigger (around the size of *Deinonychus*) and more robust than *Velociraptor*. Conversely, its sickle toe claws are highly reduced, smaller and blunter compared to the prominent ones of *Velociraptor*, indicating that *Adasaurus* did not use its sickle toe claws as much as other dromaeosaurs.

### Marginocephalians

* On Prehistoric Planet, pachycephalosaurs like *Pachycephalosaurus* and *Prenocephale* are depicted without cheeks, in sharp contrast with ceratopsians like *Triceratops* and *Pachyrhinosaurus*, which are depicted with cheeks.
	+ Using the works of Dr. Ali Nabavizadeh as justification, Dr. Darren Naish brought up how pachycephalosaurs had simpler, more primitive teeth, and hence chewed food more like a lizard rather than doing so in the more complex manner in which ceratopsians and ornithopods chewed.
	+ Regardless of how this debate eventually gets resolved, current understanding has it that dinosaur cheeks aren't like those of mammals, since, contrary to popular belief, dinosaurs did not need cheeks to hold food, and one theory is that they may have had "cheeks" as a result of jaw muscles extending across the parts where true cheeks would be.
* Male *Pachyrhinosaurus* and male *Prenocephale* are depicted with keratinized bristles running down their tails (though female *Prenocephale* were also initially supposed to be depicted with tail bristles).
	+ Tail bristles (determined in a 2016 study to be highly modified scales, not feathers due to the different morphology and anatomy of these structures) are known in the primitive *Psittacosaurus*, a basal ceratopsian, and, though there is barely any evidence of such structures in later, more advanced ceratopsians or pachycephalosaurs (the other group of marginocephalians), some are occasionally depicted with similar-looking filaments running down the back and tail.

### *Mosasaurus*

* Regarding *Mosasaurus* size estimates, recent calculations as of 2022 bringing up a maximum length of 13 meters (42 feet) and a maximum weight of 5.5 metric tons (6.1 short tons), though, based on statements made in Coasts, Oceans, and the Uncovered segment "How Fast Was A Mosasaur?", Prehistoric Planet considers it to still be plausible that *Mosasaurus* reached lengths of 15 meters (50 feet) and weights of up to 15 metric tons (16.5 short tons). Nevertheless, the shorter length of 13 meters (42 feet) is used in "How Fast Was A Mosasaur?" to calculate the speed of acceleration of *Mosasaurus*.

### *Therizinosaurus*

* *Therizinosaurus* is erroneously shown with its fourth toe raised off the ground. Unlike most theropods, which walk on three toes while the fourth is reduced to a useless dewclaw, the fourth toes of therizinosaur feet are functional and weight-bearing.

### Titanosaurs

* Some of the titanosaurs on Prehistoric Planet have thumb claws, even though most (but not all) titanosaurs had specialized feet that lacked fingers. One exception to this is *Rapetosaurus*, which is correctly depicted without foot claws.

### Tyrannosaurids

* Although feathers are known in basal tyrannosauroids like the 9-meter (30-foot) proceratosaurid *Yutyrannus huali* (the largest feathered animal known so far), *T. rex* skin impressions lack direct evidence of feathers, indicating that *T. rex* and other advanced members of the tyrannosauroid superfamily were, for the most part, scaly. However, based on the exhibit by paleontologist Mark Norell, the *T. rex: The Ultimate Predator*, recent and more accurate studies helped the reconstruction of a juvenile *T. rex* model. Hatchlings may have been covered in feathers, which prompted the scientists involved to propose that, while *T. rex* was primarily covered in scales, it also had a mullet of feathers on its head, neck, and tail.
	+ With these findings, Prehistoric Planet chose to portray *T. rex* with a coat of feathers when young, the animal gradually losing its plumage as it grows, until all that is left on the adults are some faint, almost hair-like remnants. *Tarbosaurus* of the Nemegt Formation in Mongolia is also depicted with almost unnoticeable feathering.
	+ *Qianzhousaurus* is portrayed with a moderately-thick coat of feathers, given that it lived in the cold, temperate forests of the Nanxiong Formation in southern China.
	+ *Nanuqsaurus* is shown with thick, dark plumage since it lived in the Prince Creek Formation of Alaska, USA (though warmer than today, the region would have still undergone cold, dark winters). *Nanuqsaurus* (given its correct height of 9 meters or 30 feet) was also around the same size as *Yutyrannus*, serving as further justification of its depiction as a heavily-feathered animal.
* Although there is no evidence showing tyrannosaurs taking care of their young (whether it involves only one or both parents), based on crocodiles, birds, other theropods like oviraptorids, and even other dinosaurs that are not so closely related like the hadrosaur *Maiasaura*, it is possible that tyrannosaurs did indeed raise its young (though if so, the next evidence to look out for is which parent took care of the chicks, or if both did).
	+ The first segment of Coasts depicts only the male *T. rex* taking care of his offspring to a degree, though the show depicts *T. rex* more like an r-strategist species, given how it is stated that they spawn at least 15, with around two-thirds dying off in their first year (r-strategist animals rely on multiple offspring, many of which are expected to perish before reaching adulthood). He is also shown leading his children around to safer places where more food can be found, but do not seem to provide extensive parental care, for, unlike *Masiakasaurus*, *Pectinodon*, and *Nanuqsaurus*, three theropods on the show that still provide food for their hatchlings (and thus appear to be K-strategists, animals that provide extensive parental care to their offspring), *T. rex* refuses to share the turtle he scavenged with his children, forcing them to find food on their own. This aspect also seems to be in-line with the r-selection strategy, which involves a lesser degree of parental care.
	+ For *Nanuqsaurus*, it is the female that takes care of the juveniles, as depicted in the fifth segment of North America.

#### *Nanuqsaurus*

* By the time Prehistoric Planet was being made, *Nanuqsaurus* was originally viewed as a dwarf tyrannosaur that grew to only 5 - 6 meters (16 - 20 feet). A study in 2021 showed that, based on some adult-sized teeth and other remains, *Nanuqsaurus* likely grew to be the size of *Albertosaurus*, and thus, while this still makes it a medium-sized predator, it is not as small as once believed to be. Because the discovery is made too late for the show to account for, *Nanuqsaurus* is inaccurately portrayed on Prehistoric Planet as a diminutive tyrannosaur.

## Specific to Coasts

### *Tethydraco*

* On Prehistoric Planet, *Tethydraco* is depicted as a pteranodontid, however, some have suggested that *Tethydraco* is actually an azhdarchid. Some studies state that its fossils do not actually indicate the remains of a distinct animal, but rather, parts of the wings of *Phosphatodraco*. If the latter case is true, *Tethydraco* will be considered a junior synonym of *Phosphatodraco*, and is thus invalid, meaning that this supposed latest member of the pteranodontid family of pterosaurs actually does not exist.

### *Kaikaifilu*

* Despite being shown hunting *Tuarangisaurus* in the waters of Zealandia, presumably the Tahora Formation, *Kaikaifilu* is only known from the López de Bertodano Formation in Antarctica.
	+ It was likely that Prehistoric Planet intended to show that, much like its relative, *Mosasaurus* (which was present worldwide), *Kaikaifilu* didn't live in just one area, thus making its presence in the waters of Zealandia plausible, an idea further supported by the fact that its slightly larger relative, the *Prognathodon*-sized *Moanasaurus*, was found in both the López de Bertodano Formation and Tahora Formation.

## Specific to Deserts

### *Secernosaurus*

* In 2022, the specimens the *Secernosaurus* of the show were based on were reclassified as a new hadrosaur, *Huallasaurus* (Duck Lizard), which lived in the Los Alamitos Formation, Argentina, 85 - 66 million years ago, from the Santonian to the Maastrichtian stage of the Late Cretaceous Period.
	+ Since these findings were not set when the show was being made, the sixth segment of Deserts essentially shows *Huallasaurus* living in the area *Secernosaurus* inhabited, the gypsum deserts of the Lago Colhué Huapí Formation, located several hundred miles southwest of the Los Alamitos Formation.

## Specific to Freshwater

### "*Velociraptor*"

*See also: General Dromaeosaurids errors and speculations, General *Velociraptor* errors and speculations*

See also: General Dromaeosaurids errors and speculations, General *Velociraptor* errors and speculations

* The concept of *Velociraptors* hunting or at least scavenging on azhdarchids is based on how one specimen was found with an azhdarchid long bone in its stomach.

### *Tyrannosaurus rex*

*See also: General tyrannosaurid errors and speculations*

See also: General tyrannosaurid errors and speculations

* *T. rex* is seen feeding on a *Triceratops* starting from the neck. As a study in 2012 suggests, *T. rex* likely focused on the nutrient-rich neck muscles behind the frill of a *Triceratops* (which, in life, were necessary to help the ceratopsian support the great weight of its head, horns and all).

## Specific to Ice Worlds

### Troodontid

* The identity of the Arctic troodontid shown in the fourth segment of Ice Worlds is left ambiguous. According to Dr. Darren Naish, the show originally considered calling it *Troodon*, *Stenonychosaurus*, or *Latenivenatrix*. Unfortunately, each name is associated with problems.
	+ The validity of *Troodon* has been called into question since 2011, and the debate regarding that continues to this day.
	+ *Latenivenatrix* may be a junior synonym of *Stenonychosaurus*, and even if it were distinct, as the largest known troodontid, *Latenivenatrix* has a 3.5-meter (11-foot) body length, twice that of this unnamed troodontid.
	+ Lastly, even if all three species were of equal validity, they all lived in the Campanian stage of the Late Cretaceous, around 77 - 75 million years ago, at least 3 - 5 million years before the show's Maastrichtian time scope. Hence, it is understandable that the species ultimately went unnamed in the show.
	+ The Prince Creek Formation was also home to still-unnamed troodontids that make up two-thirds of all fossils in the area (as opposed to other areas, where troodontids only made up 6% of the native fauna). These troodontids are almost twice as big as their cousins in Alberta and Montana, equivalent to the size of *Latenivenatrix*. However, since the Alaskan troodontids of Prehistoric Planet are stated to be only six feet in length, the show might not have intended it to be a portrayal of the large troodontid species (unless they are intended to be juvenile forms, though this is unlikely).
* Due to their large brains giving them high intelligence, troodontids may have used tactics similar to those of birds of prey today. Based on behaviors of modern-day lizards, birds, and even crocodilians, the troodontids using burning twigs as tools to deliberately spread fires to flush out prey in Ice Worlds may not be as far-fetched as it first appears.

### *Antarctopelta*

* Originally classified as a primitive nodosaurid (being reconstructed with the appearance of one on Prehistoric Planet), with the 2021 discovery of *Stegouros* in the Dorotea Formation (75 - 72 million years old) of southern Chile, a new group of ankylosaurians was established, encompassing *Antarctopelta*, *Stegouros*, and *Kunbarrasaurus*, which lived in Australia around 105 - 100 million years ago. This clade, known as "Parankylosauria", is made up of small ankylosaurs that migrated to the Southern Hemisphere and thus evolved to be quite distinct from their ankylosaurid and nodosaurid relatives in the north.
	+ Rather than possessing a tail club, *Stegouros* had several tail osteoderms that fused in the form of a "macuahuitl", an ancient Aztec weapon with razor-sharp obsidian teeth that made it seem like a combination of a sword, a club, a saw, and a paddle. While the tail of *Antarctopelta* is yet to be found, it is likely that, much like its smaller cousin, it also had a macuahuitl-esque tail.

## Specific to Forests

### *Triceratops*

*See also: General marginocephalian errors and speculations*

See also: General marginocephalian errors and speculations

* Limestone caves in the Rocky Mountains by that time, as well as the various plants of the period that may contains toxins, serve as plausible justification that *Triceratops* did engage in geophagy (consumption of soil) like many animals today, either to supplement their diet with minerals, or, as depicted on the show, to neutralize the toxins of the plants they ate.

### *Carnotaurus*

* *Carnotaurus* has its scales arranged in a neat pattern all over its body. A study of skin impressions in 2021 showed that, in truth, *Carnotaurus*, like all abelisaurs, had its scales randomly distributed across their body.
	+ This mistake was corrected for *Majungasaurus* and *Rajasaurus*, which were depicted in Season 2 of Prehistoric Planet with a more random arrangement of scales on their bodies.
* One argument regarding *Carnotaurus* using its tiny arms for display is its lack of sufficient nerve supply, much like the wings of emus and kiwis.
	+ Dr. Darren Naish counters this by bringing up how such an argument ignores cassowaries, which possess long spikes on their forearms, indicating some sort of function.

### *Therizinosaurus*

*See also: General *Therizinosaurus* errors and speculations*

See also: General *Therizinosaurus* errors and speculations

* The juvenile *Therizinosauruses* being independent of parental care is based on fossil evidence that some theropods were independent from an early age and left the nest in a sibling group.
* It's also been suggested that, while herbivorous, they would have opportunistically engaged in semi-omnivory.
* The juvenile *Therizinosauruses* are shown climbing trees clumsily. These are based on old hypotheses which are admittedly not supported today.
* It is assumed that the narration in Forests stating that *Therizinosaurus* is "30 feet high" is meant to be a reference to its length instead.
	+ However, it's been suggested by Dr. Darren Naish that a *Therizinosaurus* rearing up as tall as it can may have exceeded 7.4 meters (24 feet).

## Specific to Islands

### *Tethyshadros*

* While Prehistoric Planet was being made, *Tethyshadros* was believed to have lived 70 million years ago, during the Maastrichtian age of the Late Cretaceous Period. However, in 2021, a study reevaluated the remains of the fossil and discovered that it lived 81 - 80 million years ago, during the Campanian stage. Because the discovery is made too late for the show to adjust, *Hatzegopteryx* is shown inaccurately hunting an animal that lived at least 10 - 15 million years before it lived.
	+ Even so, the scenario depicted in the second segment of Islands could have still played out in some form. A relative of *Tethyshadros* called *Fylax thyrakolasus* lived in Spain around 66 million years ago, and remains of *Hatzegopteryx*, or, at least, azhdarchids of similar size, have been found across Europe.

### *Adalatherium*

* The idea that *Adalatherium* (and other gondwanatherians) laid eggs is a matter of debate. Based on the idea that multituberculates (which are considered close relatives of the gondwanatheres) might have laid eggs, *Adalatherium* was portrayed on the show as an egg-laying mammal.
	+ However, in a study published in 2022, just a year before the release of Season 2, an analysis of multituberculate bones suggested that multituberculates did not lay eggs, though the show's portrayal is not fully invalidated since it is still possible that gondwanatheres were different and not even closely-related to multituberculates.

### *Imperobator*

* While its full relationship with dromaeosaurs is an ongoing subject of debate, a 2023 study suggests that *Imperobator* is a large unenlagiine like the similarly-sized *Austroraptor*.
	+ If proven to be the case, rather than being a robust predator that went after similarly-sized animals like *Morrosaurus*, *Imperobator* may have instead been a sleek, primarily piscivorous animal with the same fish-eating adaptations (e.g. the long, narrow snout and conical teeth much like those of spinosaurids). This does not necessarily invalidate its capability to ambush and pursue prey like *Morrosaurus*, as one study suggests that unenlagiines were better at chasing prey than other dromaeosaurs due to their more gracile physique.

## Specific to Badlands

### *Corythoraptor*

* *Corythoraptor* is shown in the Badlands episode as living in what appears to be the Barun Goyot Formation (where *Kuru kulla* is from), despite there being no evidence of it in the area.
	+ Perhaps this was done due to speculation that the animal had a greater range than the fossil records show.
	+ Alternatively, this decision was made in order to conserve budget and avoid making another dinosaur model, thus, *Corythoraptor* may have simply been reused to serve as a stand-in for *Conchoraptor*, *Heyuannia*, or *Nemegtomaia*, the three oviraptorids known from the Barun Goyot Formation.

## Specific to Swamps

### *Shamosuchus*

* *Shamosuchus* lived in the Djadochta Formation in what is now the Gobi Desert of Mongolia during the Campanian Stage of the Late Cretaceous Period, not during the Maastrichtian Stage, the time Prehistoric Planet is set in. The animal depicted on Prehistoric Planet is actually meant to be *Paralligator* (Near Alligator), which is known from the Nemegt Formation (a successor of the Barun Goyot Formation, which was in turn the successor of the Djadochta Formation) during the Maastrichtian stage of the Late Cretaceous Period. Both *Shamosuchus* and *Paralligator* have been considered one and the same by some studies in the past, though it is now believed that, while closely related, they were distinct from one another given their differences, like the significantly shorter snout of *Shamosuchus*.
	+ The segment of *Shamosuchus* is set in is actually the Songliao Basin of China (which does contain crocodylomorphs, though none are confirmed to be *Shamosuchus*), which is around 83 - 85 million years old. However, a comment from Dr. Darren Naish implies that it was still meant to take place during the Maastrichtian stage of the Late Cretaceous, around 72 - 66 million years ago, indicating that this particular section of the Songliao Basin is much younger than its other parts. Even so, while both *Shamosuchus* and *Paralligator* lived slightly before Prehistoric Planet's mostly Maastrichtian setting, it is still reasonable enough to believe that some of them did persist a bit longer past the time range indicated by their fossils.

### *Austroraptor*

* The sickle toe claws of *Austroraptor* appear too reduced in form. Its sickle claws were originally meant to be more strongly curved and pointed as indicated by preserved keratin sheaths, but filming constraints unfortunately prevented changes from being made to the animal's digital model.

### *Pachycephalosaurus*

*See also: General marginocephalian errors and speculations*

See also: General marginocephalian errors and speculations

* The *Pachycephalosaurus* on Prehistoric Planet is based on the "Sandy" specimen, which has spiked knobs as opposed to blunt knobs. The taxonomy of *Pachycephalosaurus* is, to this day, subject to continuous debate, with conflicting views regarding this spike-crowned form being either a growth stage of the sole species, *P. wyomingensis* (which appears to still be the common consensus), or a second species known as *P. spinifer* (previously interpreted as a distinct genus known as *Stygimoloch*, which means "Styx River Demon") that lived slightly later than *P. wyomingensis*. Hence, the identity of the species on Prehistoric Planet depends on the validity of *P. spinifer* as a second species.
* The fourth segment of Swamps depicts the pachycephalosaurs as running through a dry, open area, an inland basin said to have once been several feet deep in water, rendered bone-dry by a decade of drought. However, Dr. Darren Naish clarified that such an environment would not have been appropriate for *Pachycephalosaurus* (it was only shown in such an area because of filming constraints). Instead, *Pachycephalosaurus* would have more likely thrived in wetter, more heavily forested lowlands like the one shown in the fifth and final segment of Swamps, coexisting with other well-known dinosaurs like *Edmontosaurus*, *Triceratops*, and *T. rex*.

### *Edmontosaurus*

* The fifth segment of Swamps states that *Edmontosaurus* is twice as fast as *T. rex*, the likely basis of this being a study in 2009, which indicates that *Edmontosaurus* can reach a speed of 15.7 meters (52 feet) per second, or 57 kilometers (35 miles) per hour, when galloping on all fours, and 14 meters (46 feet) per second, or 50 kilometers (31 miles) per hour, when running on two legs, double the speed of the results that consistently come up in modern *T. rex* speed calculations.
	+ However, Dr. Darren Naish later clarified that the idea of *Edmontosaurus* being twice as fast as *T. rex* was an error, and both animals actually had a similar top speed, meaning that, given the modern estimates of the maximum speed of *T. rex* (which was calculated almost a decade after the studies regarding the running speed of *Edmontosaurus*, and thus, are more in-line with the current understanding of these animals), *Edmontosaurus* likely also ran at speeds of around 25 - 30 kilometers (15.5 - 19 miles) per hour, making it easier for a *T. rex* to catch up to one of these hadrosaurs (though ambushing prey is still more preferable for predators since it would help conserve effort, energy, and time).

## Specific to Oceans

### *Morturneria*

* Although it is only known from the López de Bertodano Formation, *Morturneria* is depicted as merely a seasonal visitor and not a year-round inhabitant of Antarctica. The idea that it may have lived in South America is based on fossil evidence of other Antarctic plesiosaurs like *Aristonectes* being found in various parts of Patagonia.
	+ While *Morturneria* likely had the physiological adaptations needed to resist the cold temperatures from endothermic (warm-blooded) metabolism to thick layers of blubber, visiting the area only during springtime, right when winter ends, is a behavioral adaptation that can help ensure the animal's survival. By avoiding the coldest time of the year, *Morturneria* doesn't need to expend as much energy or resources to maintain and stay within the acceptable limits of its physiological adaptations.

## References

### General

1. ↑ Peerless Pterosaur Could Fly Long-Distance For Days
2. ↑ Behavioral and faunal implications of Early Cretaceous deinonychosaur trackways from China
3. ↑ Feathers or Scales?
4. ↑ *The Princeton Field Guide to Mesozoic Sea Reptiles*
5. ↑ Black, Riley. Scientists Discover a Gigantic Feathered Tyrannosaur. *Smithsonian Magazine*
6. ↑ Katz, Brigit. 2012. T. Rex Was Likely Covered in Scales, Not Feathers. *Smithsonian Magazine*
7. ↑ Baby *T. rex* Was an Adorable Ball of Fluff
8. ↑ Sexton, Chrissy. 2019. New evidence reveals the real *T. rex* had feathers and massive eyes
9. ↑ Nesting at extreme polar latitudes by non-avian dinosaurs
10. ↑ An articulated pterosaur wing from the Upper Cretaceous (Maastrichtian) phosphates of Morocco
11. ↑ A new hadrosaurid (Dinosauria: Ornithischia) from the Late Cretaceous of northern Patagonia and the radiation of South American hadrosaurids
12. ↑ Pterosaurs as a food source for small dromaeosaurs
13. ↑ How to eat a *Triceratops*: large sample of toothmarks provides new insight into the feeding behavior of *Tyrannosaurus*
14. ↑ A New Troodontid Theropod, *Talos sampsoni* gen. et sp. nov., from the Upper Cretaceous Western Interior Basin of North America
15. ↑ Anatomical, morphometric, and stratigraphic analyses of theropod biodiversity in the Upper Cretaceous (Campanian) Dinosaur Park Formation
16. ↑ The giant troodontid dinosaurs of Alaska
17. ↑ Elgon elephants on Mount Elgon Foundation
18. ↑ The Elusive Elgon Elephants
19. ↑ The scaly skin of the abelisaurid *Carnotaurus sastrei* (Theropoda: Ceratosauria) from the Upper Cretaceous of Patagonia
20. ↑ Scientists reveal the fossilized skin of a bull-like carnivorous dinosaur
21. ↑ *Tethyshadros* did not come from the Maastrichtian, but instead from the Campanian Stage of the Late Cretaceous Period.
22. ↑ *Tethyshadros* likely had Maastrichtian relatives or descendants like it.
23. ↑ New Insights into Unenlagiine (Theropoda: Paraves: Dromaeosauridae) Diversity, Paleoecology, and Paleobiogeography Derived from Late Cretaceous Fossils from Patagonia and Antarctica
24. ↑ Differential locomotor and predatory strategies of Gondwanan and derived Laurasian dromaeosaurids (Dinosauria, Theropoda, Paraves): Inferences from morphometric and comparative anatomical studies
25. ↑ Efimov, M. B. (1983). "Review of fossil crocodiles of Mongolia". *Transactions of the Joint Soviet–Mongolia Paleontological Expedition*. **24**: 76–95.
26. ↑ Rozhdestvenskiy, A. K. (1974). "History of the dinosaur fauna of Asia and other continents and questions concerning paleogeography". *Transactions of the Joint Soviet–Mongolia Paleontological Expedition*. **1**: 107–131
27. ↑ Storrs, G. W.; Efimov, M. B. (2000). "Mesozoic crocodyliforms of north-central Eurasia". In Michael J. Benton; Mikhail A. Shishkin; David M. Unwin; Evgenii N. Kurochkin (eds.). *The Age of Dinosaurs in Russia and Mongolia*. Cambridge University Press. pp. 402–419
28. ↑ Turner, A. H. (2015). "A Review of *Shamosuchus* and *Paralligator* (Crocodyliformes, Neosuchia) from the Cretaceous of Asia".
29. ↑ Virtual Palaeontology: Gait Reconstruction of Extinct Vertebrates Using High Performance Computing
30. ↑ Why *Tyrannosaurus* was a slow runner and why the largest are not always the fastest
31. ↑ Walk the dinosaur: New biomechanical model shows *Tyrannosaurus rex* in a swinging gait
32. ↑ New Study Finds *T. rex* Walked at a Slow Pace of Three Miles Per Hour

### Dr. Ali Nabavizadeh

1. ↑ New Reconstruction of Cranial Musculature in Ornithischian Dinosaurs: Implications for Feeding Mechanisms and Buccal Anatomy
2. ↑ Dinosaurs did not need cheeks to hold their food since they don't chew from side to side the way mammals do.

### Dr. Darren Naish

1. ↑ 1.0 1.1 *Hatzegopteryx* was likely an island-hopping pterosaur, an idea backed up by the remains of similar azhdarchids found across Europe.
2. ↑ Sexual dimorphism is inferred for azhdarchoids, and melanosomes on azhdarchoid crests indicate how colorful they were, further supporting their role in sexual display.
3. ↑ 3.0 3.1 The *Velociraptors* in Deserts are based on indeterminate velociraptorine remains, though it is possible that these may indeed be *Velociraptors*.
4. ↑ The animals in Freshwater are not specifically *Velociraptors*, but the show cannot refer to them "indeterminate velociraptorines".
5. ↑ Pachycephalosaurs likely lacked cheeks because of their primitive teeth.
6. ↑ After basing off of Dr. Ali Nabavizadeh's works regarding pachycephalosaur chewing styles, the decision was made to depict pachycephalosaur anatomy as being more fit for lizard-style chewing as opposed to the more complex chewing styles of ceratopsians and ornithopods, further showcasing the anatomical diversity of ornithischians.
7. ↑ Most (but not all) titanosaurs lacked fingers, though some of the titanosaurs on Prehistoric Planet were incorrectly modeled with thumb claws.
8. ↑ The *Secernosaurus* in Deserts was reclassified as *Huallasaurus* in 2022.
9. ↑ The names *Troodon*, *Stenonychosaurus*, and *Latenivenatrix* were considered for the Alaskan Troodontid, though it was ultimately referred to by just its group name on Prehistoric Planet.
10. ↑ The concept of troodontids deliberately spreading fire is based on how modern-day predatory birds spread forest fires to flush out prey. While it is yet to be confirmed whether troodontids were similar to modern-day predatory birds in terms of cognitive abilities and behavioral flexibility, it is reasonable given the the surprisingly flexible and innovative ways of modern lizards, birds, and crocodilians.
11. ↑ *Triceratops* may have visited caves much like the elephants, rhinoceros, and bushbucks of Mt. Elgon in Kenya, Africa visit underground caves to mine salt-rich clay, and the Rocky Mountains, which were just rising around that time, likely had many limestone caves that can potentially provide these clay licks. Such behavior is widespread in the natural world today, mining rock faces for mineral content, either to neutralize the toxins of the plants they digested, as depicted on Prehistoric Planet, or to supplement their diet with various minerals.
12. ↑ The idea that *Carnotaurus* lacked an adequate nerve supply to play any important role is based on comparisons with the useless wings of emus and kiwis, but this argument ignores cassowaries, which have long spikes on their forelimbs that may have played an important role.
13. ↑ Fossil evidence suggests that the juveniles of at least some theropods were independent and left the nest in a group.
14. ↑ Therizinosaurs may have opportunistically consumed fungi and fruits, and they might also be semi-omnivorous, especially the juveniles.
15. ↑ There was once a hypothesis in the 1990s that suggested that therizinosaurs were tree climbers, a view not supported in the modern day.
16. ↑ The narration stating that *Therizinosaurus* is "30 feet high" (believed by some to actually mean "30 feet long") is not an error, for *Therizinosaurus* could exceed 7.4 meters (24 feet) in height when standing up as tall as it can.
17. ↑ While there is no direct evidence for the reproductive behavior of *Adalatherium*, with some experts divided regarding whether they laid eggs or gave birth to live young, the show ultimately following through the decision to portray the animal as egg-laying, with a strategy different compared to those of egg-laying mammals today.
18. ↑ While multituberculates may not have laid eggs, the same may not necessarily be true for gondwanatheres, which may not be closely-related to multituberculates at all.
19. ↑ The animal depicted in the first segment of Swamps should have been *Paralligator*, since *Shamosuchus* has a much shorter snout than it. Although *Shamosuchus* and *Paralligator* precede Prehistoric Planet's Maastrichtian setting, it is reasonable enough to speculate that some of them may have survived for longer than the fossil records show.
20. ↑ The sickle toe of *Austroraptor* was supposed to be more strongly curved and pointed as indicated by preserved keratin sheaths, but the manufacturing of a physical leg and foot prop (that ultimately went unused because it didn't look real enough) prevented any further changes from being made to the digital model of *Austroraptor*.
21. ↑ Prehistoric Planet's *Pachycephalosaurus* is based on the Sandy specimen, and its taxonomy is still not sorted out.
22. ↑ Regardless of whether they are a separate species or not, the spike-crowned *Pachycephalosauruses* are depicted as a distinct population, given how they are found in a rock layer different from that of the non-spiked variants.
23. ↑ *Pachycephalosaurus* should have been featured in well-watered, densely forested lowlands, and its habitat as portrayed on Prehistoric Planet is inappropriate, having resulted from the constraints of making the show.
24. ↑ The idea that *Edmontosaurus* is twice as fast as *T. rex* is a mistake, the narration was instead supposed to state that both animals had a similar top speed.

### Dr. Thomas Holtz

1. ↑ The indeterminate velociraptorines of the Nemegt Formation may one day be considered a new, legitimate species of *Velociraptor*.
2. ↑ Lecture 17 Thyreophora Defense! Defense! DEFENSE!!

### Prehistoric Planet

1. ↑ Gabriel Ugueto, one of the designers who worked on Prehistoric Planet, showed *Prenocephale* concept art and confirmed that the tail bristles of the females were removed on the show, making the bristles a male-exclusive feature.
2. ↑ I Know Dino: The Big Dinosaur Podcast, Episode 445: Dinosaurs in Swamps: Featuring Prehistoric Planet 2