Trace of 'bone-crushing' dog found at Tennessee fossil site

This undated photo provided by Ludovic Slimak shows scientists working at the entrance of the Mandrin cave, near Montelimar, southern France. Scientists have uncovered fossilized modern human remains and tools sandwiched between Neanderthal remains and tools in the stratigraphic record at a site in the Rhône Valley in France, suggesting occupation of the area alternated between Neanderthals and modern humans. (Ludovic Slimak via AP)

JOHNSON CITY, Tenn. (AP) -- East Tennessee State University says researchers have discovered evidence of the extinct "bone-crushing" dog at a fossil site that also included herbivores, a sabretooth cat and alligators.

The university says it identified the Borophagus dog at the Gray Fossil Site by finding a single right humerus upper arm bone. The "bone-crushing" animal had powerful teeth and jaws.

The university says this is the first evidence of a dog there. The animal has been discovered at dozens of fossil sites across the U.S and Mexico, usually alongside plants and animals from open environments like grasslands.

Fossils at the Gray Fossil Site depict a densely forested habitat with lots of forest plants and tree-dwelling animals.