It's the only animal that waddles like that. It is a surreal creature...with a funny name. It's called an Arsinoitherium. These creatures have extraordinary horns.
— Allen, about Arsinoitherium
in The Big Blue Killer Whale

Arsinoitherium (name meaning "Arsinoe's Beast") is a genus of paenungulate mammal that originated during the Late Eocene epoch in what is now Africa. Closely related to the Moeritherium, it is significant for having a hollow, double horn on its head.

In the episode "Big Blue Killer Whale", a small group of Arsinoitherium were brought back to the park.


Era & DiscoveryEdit

Arsinoitherium lived during the Late Eocene to Early Oligocene epoch, from 38–27 million years ago. It was first unearthed in 1902 and gets its name from a very ancient Egyptian Queen, Arsinoe II.

Physical AttributesEdit

Standing more than 5 feet (1.75 m) tall, measuring 10 feet (3 m), and weighing 2 tons, Arsinoitherium was a massively large herbivorous animal, slightly larger than a hippopotamus, and the shape of a modern rhinoceros. However, its legs were better adapted to life in the water rather than on land. Therefore, it waddled, meaning these creatures swung the weight of their bodies from side to side and tracks are widely spread, just like a camel. Arsinoitherium was almost entirely grey with a white underbelly and marks across the side of its face.

The most striking and distinctive feature of Arsinoitherium are the two pairs of large, double horns that adorn the skull. Whereas the male's horns were splay out, the females were larger and much more vertical. One small pair of knobs sit above the eyes, and a far larger and very broad pair of horns, protrude in front of the eyes - and consequently would have created an awkward blind-spot directly in front of its own nose. Its double horn was hollow and given that and that both sexes had excellent hearing, it is possible that the animal could produce loud noises, like some of the hadrosaurs. Instead of a nose, it had a small nasal proboscis. The males may also have used their horns in mating battles, locking them with a rival and twisting until their opponent surrendered. Its teeth were designed to eat specific types of vegetation.

Despite the impressive display, the horn blocked its sight and therefore, Arsinoitherium would have to constantly turn or tilt its head frequently to see what was in front of it or even to simply look straight forward.

Behavior & TraitsEdit

Arsinoitherium, at times, has been known to be solitary creatures, only getting together during mating season. The horns were what males use for defense and for fighting. These creatures might have looked like, or at least, similar too rhinos, but they were, in fact, more closely in relation to elephants. What is more surprising is that they lived like hippos.

Arsinoitherium could be described as a sea monster, but at least they were amphibious ones. There was plentiful food in mangroves for huge vegetarians like these. The teeth of Arsinoitherium were unique. Because of this, they were restricted to specific types of vegetation. It preferred eating fruit over leaves or twigs. Arsinoitherium was adapted to deal with the changing tides.'

Despite its size and aggressive appearance, Arsinoitherium was actually a gentle giant. It lived in the North African coastal mangrove swamps, where it would have spent most of its time wallowing in the water. Arsinoitherium would emerge on to land only for brief periods of time because its hind legs were permanently bent and pointed outwards, which was ideal for swimming but not so good for walking. Its awkward gait has been confirmed by the discovery of its fossilized footprints in Egypt. It is thought that Arsinoitherium would have ventured on to land to mate or to move to new feeding areas. It had no natural predators on land or in the sea.



  • The sound effects of Arsinoitherium are that of bull, camel, elephant, hippopotamus, rhinoceros, and walrus sound effects.
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