Earth has existed for a very long time, and many animal species have lived on its surface. Evolution enabled some to adapt to new climates, while others didn’t do so well and went extinct.

We can all safely agree that dinosaurs were absolutely awesome! However, today’s focus will be on another extinct animal that isn’t really well known.

Nowadays, this animal is known as the bear dog. In 1986, fossils were found in southwestern Texas, and it appears that they belong to bear dogs!

A new study not only confirmed this, but also suggested that bear dogs might have even originated from this part of the continent. Even though they were really small when they first appeared, some managed to evolve and become excellent predators several million years ago.


Bear dogs, or amphicyonids as they are scientifically known, get their name from the resemblance they have with bears and dogs.

However, even though bear dogs resemble present day bears and dogs in posture and overall body shape, they are not closely related to their lineages. According to one vertebrate paleontologist, these creatures first appeared around 40 million years ago, at a time where neither dogs nor bears had yet evolved.

At the time of it appearance, a bear dog weighted only several pounds. Nonetheless, over the time span of several million years, this animal lineage evolved to a much bigger size, from fox sized all the way to bear sized!

Furthermore, these animals were all meat eaters, no matter what their size was. Even though it isn’t clear where they appeared first, bear dogs lived in North America, Asia and Europe.

This animal was discovered after Susumu Tomiya, a vertebrate paleontologist, saw a fossil in the Museum of Natural History in Chicago.


He thought that this is an unrecognized species, and he and fellow paleontologist Jack Tseng decided to take a closer look at this fossil and a similar one found in the same area, around 180 miles southeast of El Paso, Texas.

It was found that both of the fossils were between 37 and 38 million years old. Furthermore, one was the size of a modern day Chihuahua, while the other one was slightly bigger, the size of a house cat.


When the fossils of the extinct animal were first discovered back in 1986, it was only described as some sort of carnivore. However, with the advances in technology, the fossils were found to belong to the amphicyonids.

This discovery just added to the diversity of bear dogs, dubbing the small extinct animals ‘’lost cousins’’ of the amphicyonids.

Fossils have also been discovered in Europe. Nevertheless, with the discovery of the new fossils in southeastern Texas, it is clear that this was the hot spot of evolution for the bear dogs. As a matter of fact 6 different bear dog species have been found just in this area!

What brought these animals to extinction is still unknown. According to a paleontologist from the University of Chicago, the competition from the ancestors of present day dogs and cats is what brought an end to the bear dogs. He thinks that bear dogs didn’t adapt well to the new climate and ecosystems, and they eventually went extinct.

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