Earliest Beardogs Lived in Texas 38 Million Years Ago

Posted on October 11, 2016

Ancient Beardog

Scientists have identified fossils of the earliest and most primitive members of the beardog family. The ancient beardogs were identified from 38 million year old fossils found in Texas. The fossils were part of the The Field Museum collections.

The prehistoric dog relatives were the size of Chihuahuas. The species identified from the fossils have been named Gustafsonia and Angelarctocyon. Some later members of the beardog family were much larger.

Susumu Tomiya, a postdoctoral scholar at The Field Museum, says in a statement, "We've known about these curious little critters for 30 years, but couldn't tell exactly what kind of carnivores they were."

Tomiya also says, "By about 15 million years ago, the beardog family had given rise to huge predators bigger than modern lions, but the early members reported in this study were tiny, around the size of a Chihuahua. There are advantages to being bigger--you can take down bigger prey, you have fewer predators and fewer competing carnivores that can steal your food--but there are disadvantages too. Bigger animals require more food and space, and they reproduce more slowly. Larger animals go extinct at higher rates than smaller animals--recent studies suggest that getting bigger may be a dead-end strategy in mammalian carnivores. Studying how the diversity of beardogs waxed and waned over time could tell us about larger patterns in carnivore evolution."

A research paper on the ancient beardogs was published in the journal, Royal Society Open Science.

Image: Monica Jurik, The Field Museum