Evolutionary history of dogs seem to include Bear dogs

Evolutionary history of dogs seem to include Bear dogs

Evolutionary history of dogs seem to include Bear dogs
Fragmentary fossilized carnivore remains that sat largely unnoticed in a drawer at Chicago's Field Museum after being unearthed in southwestern Texas nearly three decades ago belonged to a strange group of extinct species known as "bear dogs."

A new analysis of the fossils suggested that bear dogs, which lived in North America as many as 40 million years ago, were early part of the evolutionary history of today's dogs, foxes and weasels. Though bear dogs were only about the size of a Chihuahua, they were among top predators in their ecosystems millions of years ago.

According to the researchers, the fossilized jawbones belonged to two closely-related kinds of Chihuahua-sized bear dogs, dubbed Gustafsonia and Angelarctocyon.

Steven Wallace, a curator at East Tennessee Natural History Museum, said, "It's almost like they feel that once a specimen's been described, they've learned everything they can from it. Sometimes the coolest discoveries come right out of a museum."

Susumu Tomiya, a vertebrate paleontologist at Chicago, Illinois-based Field Museum of Natural History, said that neither bears nor dogs had evolved when bear dogs first appeared roughly 40 million years ago.

The findings, published Wednesday in the journal Royal Society Open Science journal Royal Society Open Science, are expected to help researchers learn more about the evolution of dogs and other carnivores as well as how animals adapted to drastic changes in climate.

Tags: 
Location: