Incredible Discovery of Rare Giant, Cat-Sized Flying Squirrel Fossil Leave Researchers Baffled
It is always fascinating to understand how a particular creature evolved through time. In some cases, the change is so massive that experts get stunned. This is what happened when researchers analyzed some remains that had been discovered around 25 years ago in Tennessee, stated Live Science. Findings regarding the remains were published in the Journal of Mammalian Evolution.
The remains were unearthed from an ancient sinkhole at Gray Fossil Site. A particular fossil was found to belong to an extinct genus of flying squirrels, Miopetaurista. The finding was valuable for experts as it was proof of the creature's past existence in North America. Before these findings, most fossils of these beings were located in Asia. "It is amazing to imagine these giant flying squirrels gliding over rhinos and mastodons living in the forests of Tennessee 5 million years ago," study co-author Joshua Samuels, an associate professor of geosciences at East Tennessee State University, said.
The fossil associated with the ancient flying squirrel was a single tooth. The other remains possibly belonged to the animals that inhabited the region along with the flying squirrel. Researchers think that the flying squirrel entered North America through the Bering Land Bridge in the early Pliocene period (5.3 million to 2.6 million years ago). The bridge connected Asia with North America, making it easy for the creature and other beings, to move back and forth. East Tennessee University informs that the Gray Fossil Site is around 4.5-5 million years old.
Examination of the tooth unveiled that these flying squirrels were twice as large as present-day tree squirrels and about the same size as a house cat. Experts believe they must be around 1.5 kilograms in weight. This is much more than that of Tennessee's northern flying squirrel (Glaucomys sabrinus), who weigh around 71 grams.
The fossil site was surrounded by forests, and therefore, might have served as a drinking source for many ancient species. Over several millennia, sediment and mud filled the sinkhole, burying with it several animals that died in the area. Experts claim that Miopetaurista chose Tennessee as their habitat because the then environment of the region was very similar to what they were used to in Asia. Before this finding, only two specimens of Miopetaurista fossils had been located in North America. Both of them were unearthed in Florida. These past specimens were younger than the age of the Gray Fossil Site. Hence, the remains of the flying squirrel could be the oldest known Miopetaurista fossil discovered in North America to date.
Researchers think these creatures became extinct due to changes in conditions around 2.6 million years ago (Pleistocene). The Ice Age made the warm forests of Tenessee cold, so much so that flying squirrels could no longer exist in the area. "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,” study co-author Montserrat Grau-Camats, a researcher at the Catalan Institute of Paleontology in Spain, added.