ETSU fossil site reveals giant flying squirrel

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 discovery marks one of the latest finds from the Gray Fossil Site and Museum, a prehistoric treasure trove unearthed 25 years ago.  

The findings, published in the “Journal of Mammalian Evolution,” come from a team of researchers, including Montserrat Grau-Camats and Dr. Isaac Casanovas-Vilar from the Institut Català de Paleontologia in Barcelona, Spain, along with Dr. Joshua Samuels of the East Tennessee State University Department of Geosciences and Gray Fossil Site and Cheyenne Crowe, an alumna of ETSU’s paleontology master’s program. 

“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.”