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, roughly the size of a modern house cat, once glided through the skies over what is now Southern Appalachia, soaring above ancient rhinos, mastodons, and red pandas.
This discovery is among the latest from the Gray Fossil Site and Museum, a rich prehistoric deposit first uncovered 25 years ago.
The findings, published in the Journal of Mammalian Evolution, were led by a research team including Montserrat Grau-Camats and Dr. Isaac Casanovas-Vilar from the Institut Català de Paleontologia in Barcelona, Spain; Dr. Joshua Samuels from East Tennessee State University’s Department of Geosciences and Gray Fossil Site; and Cheyenne Crowe, an ETSU paleontology master’s program alumna.
“Finding Miopetaurista in North America was quite unexpected as this genus is only known from Eurasia,” said Casanovas-Vilar. “There had been some uncertain reports from Florida, but the specimen of the Gray Fossil Site provided new information and helped to confirm that somehow these giant flying squirrels crossed the Bering Land Bridge alongside other mammals about 5 million years ago.”
An ancient environment
Appalachians today might be tempted to think of these ancient critters as closely related to the squirrels they regularly see. But their closest relatives are the giant flying squirrels in Japan, China ,and Indonesia.
These giant flying squirrels had a lightweight build, weighing around three pounds – and were quite agile in the treetops.
When they arrived in what is now Tennessee, the world was much warmer than it is now. That warmer climate allowed the squirrel’s ancestors to cross into North America, likely gliding through dense, humid forests like those preserved in the fossil record at Gray millions of years ago.
But the Ice Ages brought sweeping changes.
“As the climate cooled over time, the Pleistocene Ice Ages led to the isolation of these giant flying squirrels in warmer refuges like Florida, and ultimately contributed to their extinction,” said Grau-Camats. “The last American Miopetaurista lived millions of years after all Eurasian species of this genus had disappeared, meaning at the time they were ‘living fossils.’”
Still making history
Overseen by the Don Sundquist Center of Excellence in Paleontology at East Tennessee State University, the Gray Fossil Site is still rewriting the history of Appalachia’s ancient forests.
The giant flying squirrel is the latest in a string of fascinating discoveries, including the bone-crushing dog.
“It is amazing to imagine these giant flying squirrels gliding over rhinos and mastodons living in the forests of Tennessee 5 million years ago,” Samuels said. “This really points to the potential of the Gray Fossil Site to keep surprising us after 25 years.”
Reference: “Gliding between continents: a review of the North American record of the giant flying squirrel Miopetaurista (Rodentia, Sciuridae) with the description of new material from the Gray Fossil Site (Tennessee)” by Montserrat Grau-Camats, Isaac Casanovas-Vilar, Cheyenne J. Crowe and Joshua X. Samuels, 21 February 2025, Journal of Mammalian Evolution.
DOI: 10.1007/s10914-025-09751-w
Never miss a breakthrough: Join the SciTechDaily newsletter.
Follow us on Google and Google News.
4 Comments
I want to know how they knew Rhinos and Mastodons used to glide alongside flying squirrels.
“Researchers uncovered fossils of a giant, cat-sized flying squirrel that glided over prehistoric Southern Appalachia alongside mastodons, rhinos, and other ancient creatures.”
The flying squirrel glided, not the larger beasts.
How could they have even existed if the world was ‘much warmer than it is now’? Wouldn’t they all be underwater?
Whether naturally occurring or man-made, climate change isn’t the pending disaster we’ve been told, and the proof is there in the fossil record. Take a breath and calm down.
More or less what I was about to say.