JOHNSON CITY, Tenn. (WJHL) — A new species of kangaroo rat was discovered in Oregon by an East Tennessee State University (ETSU) scientist.

This new species, discovered at a fossil site in Oregon, is named Aurimys xeros, which means ‘ear mouse from dry habitats.’ Found at a site that preserves an ecosystem that is about 23 million years old, the fossil is reportedly the oldest known kangaroo rat.

The fossil discovered at the site consisted of a complete skull and a partial foot.

The kangaroo rat fossil was identified as a new species in the peer-reviewed journal PeerJ. Dr. Joshua Samuels, an associate professor in the ETSU Department of Geosciences and curator at the Gray Fossil Site and Museum, is credited as the leader of the study.

Modern kangaroo rats hop on two feet, just like kangaroos, and have large ears which help them survive in flat, arid landscapes, a release from ETSU stated.

Aurimys is reportedly the largest known species of kangaroo rat. Modern species can get as big as 12 inches long, but Aurimys appear to have been one-third larger. It’s possible that this extra bulk served as added protection against danger, Samuels stated.

“Since there is not much cover in open habitats,” said Samuels, “they must use their excellent hearing and erratic hopping movements to help them escape from predators like rattlesnakes and owls.”

Aurimys also do not appear to have been bipedal like their modern relatives, based on the entry point of the spine to the skull.

Early stages of kangaroo rat evolution coincide with a global climate shift, according to Samuels.

“As climate changed, forests started to decline in many places, and were replaced by more open environments like deserts, steppe and grasslands,” Samuels said. “Kangaroo rats thrive in those habitats today, and are now some of the most common mammals in arid parts of western North America.”