The largest carnivorous beast in the world, Arctotherium stands 13 feet tall, weighing up to a ton and a half, and is more muscular than any other bear.
— Allen, about Arctotherium
in Mammoth Undertaking Journey

Arctotherium (name meaning "Arctic Beast") is a genus of large bear that originated during the Early Pleistocene epoch in what is now North and South America as well as Europe and Asia. The apex predator of the Ice Age, Arctotherium was also the largest species of bear that ever existed as well as arguably the largest terrestrial mammalian predator of all time, standing 4 meters on its hind legs and weighing 2 tons.

In the Series 3 finale "Mammoth Undertaking Journey", an individual Arctotherium, a male named Kodi, was encountered several times by the Team. Having chased them around his entire territory, Kodi was brought back to the park from Siberia of 30,000 years ago. His enclosure is a cold cave environment added with some forestry and a river full of fish. He also lives with his mate Alaka.


Era & DiscoveryEdit

Arctotherium lived in North America, South America, Europe, and Asia during the Pleistocene epoch, around 2 million years ago, and died out at the end of the Ice Age around 10,000 years ago. Undoubtedly the apex predator of the Ice Age, it lived alongside animals like the Hagerman Horse, Camelops, the American Lion, and the Woolly Mammoths and Columbian Mammoths.

Arctotherium was discovered and named by Hermann Burmeister in 1879.

Physical AttributesEdit

More powerfully built than any other species of bear, physically, Arctotherium looked very similar to regular Kodiak bears, only much larger and more muscular. In fact, Arctotherium was also the largest species of bear ever discovered, standing 6 – 7 feet (2 – 2.2 m) on all four legs, reaching a rearing height of 11 – 14 feet (3.4 – 4.3 m) tall, and weighing around 1 – 2 tons (2,000 – 4,000 lbs). This makes Arctotherium arguably the largest and most powerful terrestrial mammalian carnivore of all time, larger than the largest modern Polar bear and rivaled by Andrewsarchus and Hyaenodon.

Despite their large size, Arctotherium was a very fast animal, able to reach speeds in excess of 20 – 45 mph (32 – 72 km/h) and run over a long distance. This is because their front and rear legs were equal in length as opposed to even the largest modern bears in which their front legs are shorter than their back legs, which allows them to reach speeds of up to 35 mph (53 km/h) and run over a short distance. Arctotherium was also an exceptional swimmer, much like modern polar bears.

Unlike some bears, Arctotherium did not have fatty humps on their backs. They also exhibited major sexual dimorphism, as the female of the species was much smaller in size than the quite large male. Although Arctotherium was gigantic, it was incapable of climbing trees like most modern bears.

Regardless of gender or size, Arctotherium was a very large mammalian carnivore. They had long arms armed with sharp claws and, much like Tyrannosaurus rex, they also had a mouth of bone-crushing teeth, though not quite as strong. Arctotherium also had a thick hide which kept them warm during the winter. However, despite these attributes, Arctotherium did have one weakness; their underside. Whenever they stood on their back legs, another animal could attack them at their underside. Because of their giant size, Arctotheriums were also very physically strong animals. All these attributes make Arctotherium the most powerful terrestrial mammalian carnivore of all time.

Behavior & TraitsEdit

Like many mammalian carnivores, Arctotherium was both a social and solitary animal. As with many species of bears, Arctotherium lived in large and fairly deep caves. The caves would start out as a relatively long walkway while the main section would be a large den where the bear would sleep or eat. The females were highly protective of their cubs and the males were known to be cannibalistic, eating a bear cub if they were ever hungry. Males had large territories of around 200 square miles (518 square kilometers).

As with most other bears, though hypercarnivorous, even Arctotherium was also a generalist feeder, not being a very carnivorous bear and, therefore, eating berries and vegetation, as well as scavenging carrion, and killing other animals. If necessary, they would even hunt larger prey, even ones as mighty as the Mammoth. In winter months, they would hibernate in caves like modern bears. And in order to hibernate in winter, they would eat berries and early spring vegetation as well as fish to last them several months.

When hunting, Arctotherium would stalk its prey for several minutes before attacking. When ready to attack, they would erupt out of their hiding spots, such as bushes and trees, and physically overpower and attack their prey with their teeth and claws until the prey was dead. After making a kill, Arctotherium would cover their food with leaves and dirt. They would then leave for a while, come back at a later time, and finish their meal.

If an Arctotherium was found in a cave and awoken, it would chase away, not hunt, whatever it was that disturbed it in its sleep. But either way, whether chasing an intruder, hunting prey or even fighting a rival, like all bears, Arctotherium was able to rear up on its hind legs to intimate its opponents. Unlike most bears, Arctotherium couldn't climb trees. However, they didn't need to. Much like the sauropod dinosaurs, Arctotherium were able to use their raw physical strength to bring trees and certain rocks down.

Journal EntryEdit

Perhaps nature's most savage mammal, Arctotherium was the apex predator of its time, hunting herbivores as large as the Woolly Mammoth. By its size alone, Arctotherium can overpower and devour almost anything. Standing nearly 15 feet tall, weighing over 3000 pounds, and being more muscular than any other bear, this was the largest and most powerful terrestrial carnivorous beast the world had ever seen.

In addition to its massive size, Arctotherium was immensely strong (enough so that, like the sauropod dinosaurs, they could bring down most trees) and amazingly fast, able to run at speeds fast enough to catch up to a horse and run over a long distance. This, along with razor-sharp claws and bone-crushing teeth, makes Arctotherium the most powerful terrestrial carnivorous mammal of all time.

However, predatory as they were, these bears fed on anything, like all modern bears, making them omnivorous, and they couldn't climb trees. The males had larger appearances than the females. Should you ever encounter a sleeping Arctotherium, it is unwise to startle it, let alone, wake it up. If you are unfortunate enough to disturb the most massive, foul-tempered, dangerous flesh-eater of all, that will be the last thing you ever do.

— Allen, in his Journal, about Arctotherium



  • The sound effects for Arctotherium are that of typical bear sound effects as well as bull, crocodile, elephant, lion, tiger, snake, and walrus sound effects to give it a more intimidating appearance.
  • Arctotherium died out long before 11,000 years ago. Allen even pointed this out right after the chase.
  • Arctotherium is the largest and strongest terrestrial mammalian carnivore brought to the park.
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