Nanuqsaurus (Polar Bear Lizard, named after the Iñupiaq word for polar bear) is a genus of medium-sized tyrannosaurid theropod dinosaur that served as the apex predator of the Prince Creek Formation, Alaska, USA, 71 - 69 million years ago, during the Maastrichtian stage of the Late Cretaceous Period.
While Prehistoric Planet was being made, Nanuqsaurus was believed to be a tyrannosaur that shrunk in order to adapt to the colder temperatures of the Arctic circle. Hence, they were depicted as predators that are 5 - 6 meters (16 - 20 feet) long.[3] In 2021, a study regarding the animal's remains disputed this idea, suggesting that Nanuqsaurus was actually standard in terms of tyrannosaur size. Based off of the teeth and postcranial elements of a 7-meter (23-foot) specimen comparable in size to a young Tarbosaurus,[1]Nanuqsaurus is estimated to reach a length of 8 - 9 meters (26 - 30 feet) like Albertosaurus,[2] though this study came too late for the show to adjust their depiction of Nanuqsaurus accordingly.
As with most predatory dinosaurs, Nanuqsaurus was likely endothermic, able to maintain a favorable temperature with internal bodily functions, or at least mesothermic, not fully as efficient as true endotherms, but not like ectotherms, which are primarily reliant on ambient heat. It was also likely homeothermic, capable of keeping its internal temperature stable regardless of factors outside the body, and is thus usually (but not always) warmer than the surrounding environment. In simple (albeit outdated) terms, Nanuqsaurus is "warm-blooded", and is thus able to maintain a highly-active predatory lifestyle, being quick and agile as opposed to being sluggish and lethargic like how dinosaurs were originally envisioned. This, however, comes at a cost, as such animals require a constant supply of energy for their body to continue functioning as intended. Hence, Nanuqsaurus must kill and feed regularly on sufficiently-sized prey in order to survive and stay healthy. Aside from bodily processes, warmth can also be further retained by other means, like the insulation provided by a coat of feathers.
A Nanuqsaurus and her seven offspring, feeding on a freshly-slain Ornithomimus after the end of winter for energy and heat
For tyrannosauroids, feathers appear to be a trait exhibited by basal tyrannosauroids like the 9-meter (30-foot) proceratosaurid Yutyrannus huali (the largest feathered animal known so far),[4][5] with no evidence indicating their presence on later members of the group like Nanuqsaurus, Tarbosaurus, and T. rex.[6] However, given how Nanuqsaurus is around the same size as Yutyrannus and also lived in a cold, northern region, the presence of feathers on it may be more plausible than it first appears to be.
Juvenile Nanuqsaurus concept art by Gabriel N. Ugueto
Prehistoric Planet portrays juvenile Nanuqsaurus as having light tan integument with brown, wavy, horizontal stripes and markings, allowing them to blend in with the environment while not under the protection of their parent. The adults also possess these markings, albeit less noticeable (as they no longer have the need to camouflage for safety, and their greater size makes hiding less ideal) given their dark, shaggy coats, which make them resemble Alaskan timber wolves. Dr. Darren Naish, the show's lead consultant, even confirmed that Nanuqsaurus was originally intended to have even darker coloration than the finalized design used for the show.[DN 1]
As with the other tyrannosaurs featured on Prehistoric Planet, Nanuqsaurus bears stripes on its snout, and it has been theorized that this is a trait that they all inherited from their last common ancestor. While there is no confirmation of this being the case, Dr. Darren Naish shared this fan theory, indicating a degree of support and plausibility for the idea.[DN 2] The juveniles, which were designed by concept artist Gabriel Ugueto,[PhP 1] are lighter in color compared to the adults, perhaps in order to allow them to blend in with the snowy environment of their habitat, a means to ensure their safety from other predators while their parent is away.
Three Nanuqsaurus surround a once-dominant bull Pachyrhinosaurus, ready to kill and eat him
Despite being incorrectly sized on the show, Prehistoric Planet still introduces and depicts Nanuqsaurus as "the Arctic's most powerful predator", given how the only other theropods found in the Prince Creek Formation were dromaeosaurs, troodontids, ornithomimosaurs, and birds that would not have been able to compete even against a subadult Nanuqsaurus.
Nanuqsaurus appears as the main threat in the sixth and final segment of Ice Worlds, where a pack of three attack a herd of Pachyrhinosaurus. Though the ceratopsians initially stand their ground and form a defensive circle against the tyrannosaurs, the herd eventually panics, allowing the predators to bring down an old male. Nanuqsaurus also appears in the fifth and final segment of North America, where a female tries to hunt Ornithomimus, pursuing an entire flock in hopes of catching one. Though she fails the first time, she eventually succeeds and shares her fresh kill with her hatchlings.
Nanuqsaurus, lived 71 - 69 million years ago in the Prince Creek Formation, a polar woodland that experienced 120 days of winter darkness, with temperatures dropping as low as 2 - 4 degrees Celsius (36 - 39 degrees Fahrenheit) during the cold months.
Paleofauna[]
Nanuqsaurus pack and Pachyrhinosaurus herd facing off against each other
“ Within the snow-covered forest, a tense standoff develops between ancient rivals, Pachyrhinosaurus and Nanuqsaurus. ”
― The official Apple TV+ episode synopsis for Ice Worlds
As the largest carnivore ever discovered in the region, Nanuqsaurus is the apex predator of the Prince Creek Formation, and is thus capable of hunting any of the other animals it coexisted with. Given its size, it would prefer to tackle large herbivores like Pachyrhinosaurus perotorum and Edmontosaurus, though smaller prey like Ornithomimus and Alaskacephale may suffice in certain situations.
Wherever tyrannosaurs ruled, their young tend to occupy the various predatory niches between the adult tyrannosaurs and other hunters. Given the lack of other large or medium-sized carnivores in the area, adolescent Nanuqsaurus would have occupied the mesopredator niche between those of their parents and those of the smaller hunters like Dromaeosaurus, Saurornitholestes, and the most common animals of the Prince Creek Formation, troodontids.[7]
The most successful predators are the ones that are the most adaptable, able to judge which attack strategy is the best one to use for any given situation. On Prehistoric Planet, Nanuqsaurus appears to exhibit different hunting tactics and preferences depending on the season, the environment, and the type of prey being targeted. However, not all things can be solved by plans, no matter how well thought out they are. In nature, events and actions like hunts still have an element of luck to them, hence, Nanuqsaurus, like any other predator, must also take gambles and risks, in hopes of reaping the rewards of positive results while also being ready for negative outcomes. As stated and demonstrated throughout the series, most hunts throughout the history of life are more likely to end in failure, thus, predators can do nothing more but try again until they have used up all the energy they can reasonably expend, or until a different, more decisive outcome - be it success or otherwise - is attained.
A Nanuqsaurus chases down a flock of nine Ornithomimus
“ There is nowhere to hide, so a surprise attack is impossible. Instead, she resorts to creating panic. ”
Just before winter, Nanuqsaurus is depicted as a pack hunter, willing to take on two-tonne animals together. Just when winter ends, however, Nanuqsaurus is depicted hunting alone, taking on smaller but faster prey. This may reflect the need to gain as much food and energy as possible before and during winter, when food is much harder to come by, and the need for food that can be taken down more quickly, for immediately ending hunger, even with smaller prey, is more important than playing out a longer strategy to take down prey that can stave off hunger for longer periods of time. In both scenarios, Nanuqsaurus is shown foregoing the more appealing strategy of ambush (especially out in the open, where there is no cover to hide behind) in favor of forcing their prey on the defensive, then waiting for panic to eventually take hold and reveal the weakest, most ideal target.
Three Nanuqsaurus, looking for the weakest links in the defensive ring formed by a Pachyrhinosaurus herd they are hunting
“ The herd should be safe as long as they stick together. But the Nanuqsaurs bide their time, and occasionally test for weakness. ”
Despite being depicted at two-thirds of its actual length in the sixth segment of Ice Worlds (which can be justified by the idea that the three Nanuqsaurus may be adolescents), there is evidence that even young tyrannosaurs are capable of attacking fully-grown ceratopsians successfully. One of the most significant fossils of any dinosaur is the "Dueling Dinosaurs" specimen of Hell Creek, which preserves an adolescent T. rex locked in combat with a Triceratops horridus, proving that even adolescent tyrannosaurs are capable of taking down large ceratopsians, a feat that has more chances of success when done by a pack.[8][9]
Parental Habits[]
Nanuqsaurus tends to her chicks
“ If her babies are to thrive, she will have to repeat today's success over and over again, until her young are old enough to join her in the hunt, and, eventually fend for themselves, here in this remote - and perhaps the most challenging - frontier of the North American continent, 66 million years ago. ”
As with some of the theropods on Prehistoric Planet, Nanuqsaurus is shown providing parental care to its children. Unlike T. rex and Pectinodon, where it is the father's responsibility alone, and Velociraptor, where both parents raise the children together in a family pack, it is the Nanuqsaurus mother alone that cares for the hatchlings, much like Masiakasaurus and Kuru kulla.
Gallery[]
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