Tech & Science

5-Million-Year-Old Pig-Like Creatures Discovered in Tennessee's Gray Fossil Site

Researchers have found the remains of two ancient pig-like animals that lived in the ancient forests of Tennessee around 5 million years ago.

In a study published in the open-access journal PeerJ, a team of paleontologists analyzed well-preserved bones unearthed from a location known as the Gray Fossil Site (GFS) in Washington County, east Tennessee, revealing that they represent two different extinct peccary species called Mylohyus elmorei and Prosthennops serus.

Read more: The remarkable fossil of a strange platypus-like armored fish has been discovered

Peccaries—or javelinas as they are sometimes called—are medium-size, hoofed omnivorous mammals belonging to the family Tayassuidae. They resemble wild pigs because of their dark coarse hair, tusks and large heads.

Unlike true pigs—which belong to a different family (Suidae) and are native to Europe, Asia and Africa—peccaries are endemic to Central and South America, as well as areas in the southwest of North America.

While specimens of the two extinct species described in the study have been found elsewhere in the United States before, these are the first examples to have been unearthed in either Tennessee or the wider Appalachian region, casting new light on these ancient animals, according to the team from East Tennessee State University.

“The GFS represents the only site outside the Palmetto Fauna of Florida with M. elmorei, greatly expanding the species range north over 920 kilometers, well into the Appalachian region,” the authors wrote in the study. “This is also the first Appalachian occurrence of the relatively widespread P. serus.” 

The researchers examined a number of bones to identify the animals, including lower jaw and skull remains. Analysis of the fossils showed that the peccaries were likely roughly equivalent in size to a German shepherd, which would have made them slightly larger than modern day peccaries.

The Gray Fossil Site in which they were found is a clay deposit that contains numerous ancient animal remains dating from between 4.9 and 4.5 million years ago, including rhinos, tapirs, mastodons and alligators, among others. At this time, the site was the location of a large pond in the middle of a thick oak-hickory forest.

“Details of the peccaries’ teeth suggest they spent their lives browsing on the leaves and fruits of succulent plants, so they would have been right at home in the Gray Fossil Site ecosystem, which we know from plant fossils was rich with tasty vegetation,” Chris Widga, head curator at the ETSU Museum of Natural History, said in a statement.

Mylohyus elmorei, ancient peccary, jaw View of the mandible of Mylohyus elmorei bearing right and left. Researchers have found the remains of two ancient pig-like animals that lived in the ancient forests of Tennessee around 5 million years ago. DOI: 10.7717/peerj.5926/fig-5

Editor's Pick