Researchers have identified a giant flying squirrel fossil from a cache of unusual animal remains dug out of an ancient sinkhole in Tennessee 25 years ago. The fossil sheds light on how flying squirrels reached North America.

A prehistoric giant flying squirrel once glided over ancient Appalachia but went extinct as the climate cooled. Its fossils, found at the Gray Fossil Site, reveal a surprising connection to Eurasian species.

A giant flying squirrel—about the size of today's house cats—once soared through the skies over what is now Southern Appalachia, gliding above rhinos, mastodons and red pandas.

The Gray Fossil Site was once an ancient sinkhole lake surrounded by a dense forest of hickory, oak and pine trees, scientists say. The giant flying squirrels may have migrated east on the land bridge that connected Eurasia to North America, alongside saber-toothed cats, deer, shrews and a host of other animals, according to the study.

Researchers at theGray Fossil Site and Museum in northeastern Tennessee, have recently uncovered the remains of a 4.9-million-year-old giant flying squirrel (Miopetaurista webbi). The site, which has already yielded an impressive range of prehistoric creatures,