The fossils, consisting of the beaver’s skull and several teeth were unearthed in Eastern Oregon.
Joshua Samuels, one of the paleontologists who made the discovery, said that beaver fossils were found buried at the John Day Fossil Beds National Monument.
According to Samuels, the discovery is very important because unlike previous species of ancient beavers found at the site, the newly-found fossils belong to a beaver that is related to the modern one.
The beaver is the symbol of Oregon and is included on the state’s official flag. The other species of beavers went extinct.
The newly-discovered fossils belonged to a species of beaver called Microtheriomys brevirhinus.
Experts say this species was much smaller than the modern beaver and a close relative to the the Asian beavers.
The researchers believe this species crossed the Bering land bridge approximately 7 million years ago in order to get to North America.
This beaver lived 30 million years after the dinosaurs during the Oligocene period, along with other prehistoric animals, such as the three-toed horse, giant pig, two-horned rhino, saber-tooth tiger, ancient rabbits and dogs.
The fossils discovered recently were described in the journal Annals of Carnegie Museum.
Samantha Hopkins, paleontologist at the University of Oregon, said that after the fossils are analyzed, the researchers could establish an evolutionary framework for the animal.
Hopkins wrote that even though the living beaver species is not very diverse today, there are hundreds of species fossilized, some of them very important for their animal communities.
All these fossils were found in the Northern Hemisphere, Hopkins said. The remains help the scientists understand the diversity and the evolution of the species.
According to the scientists, they were able to determine the age of the beaver fossils by analyzing the location where it was unearthed.
The fossils were found between two layers of volcanic ashes and scientists dated it using radioactive isotopes.
Samuels explained that there are plenty of badlands in the region. When these badlands get wet, either from the snow or the rain, and temperatures change from cool to hot, the claystone that holds the fossils shrinks and swells, resulting in the bones being pushed out of the earth.
Once the rocks break apart, the fossils are being exposed. The newly-found fossils got out of the ground that preserved it for millions of years.
Image Source: usnews