By: Kyle Xu
30 million years ago, a bear roamed on a river in present-day North Dakota. He appeared like a raccoon and had the appetite of an otter, named the Eoarctos Vorax. An inspection of the creature’s exquisitely preserved skeleton may provide us answers to his brief, and painful, life.
“It’s a fabulous skeleton that is just exquisitely preserved,” said Xiaoming Wang, a paleontologist at the Natural History Museum of Los Angeles County. The skeleton even included the penis, a bone that is very rarely preserved.
Dr. Wang and his team placed the creature somewhere in the evolution of mammalian animals, a group that includes cat-like, dog-like, and bear-like creatures. Based on his large molars, the scientists could tell that the Vorax belonged to the arctoids, a group of carnivores that includes bears, seals, raccoons, weasels, and otters. The arctoids share a common ancestor with dogs. This animal, however, was not an ancestor of modern bears.
The Eoractus Vorax was two feet long. They owned long, sharp claws that could’ve been used for climbing trees and escaping from predators. Though gifted with that ability, the creature was most likely terrestrial. His flat feet would have allowed him to trot long distances.
Dr. Wang thinks that the Eoractus preyed on mollusks up the rivers in North Dakota, crushing them the way our modern otters do. The creature may also have been munching on fruit with hard pits.
The Eoractus seems to be one of the first carnivores capable of crushing hard items. The studied fossil showed that the animal had broken teeth on the right side of his mouth, which soon became infected. Before those teeth healed, he seems to have damaged his left side too.
Eating might’ve been the one thing that killed this animal. Because of the male’s unworn teeth, Wang noticed that the animal died young, likely from an infection caused by his jaw injuries.
“But for all his suffering, he certainly made a huge contribution to science,” said Dr. Wang.