Fossils reveal evolution of early gliding mammals

Kramer Phillips By Kramer Phillips | 3 years ago

Remains from the first “winged” mammals have been unearthed in China, showing the adaption came about much earlier than previously believed, a new study published in the journal Nature reports.

The 160-million-year-old remains — which were discovered by a team of international researchers — revealed two new species; Maiopatagium furculiferum and Vilevolodon diplomyl. They each belonged to a group known as haramiyidans. Though the group has gone completely extinct, many researchers believe it could have been a precursor to modern mammals.

Both species are unique in that the exhibit highly specialized characteristics, including unique adaptations that allowed them to not only glide, but to roost and climb trees as well. As a result, the study shows such mammals evolved much earlier than previously thought.

“This very ancient Jurassic glider developed the first gliding adaptation, and then they went extinct,” said study co-author Zhe-Xi Luo, a paleontologist from the University of Chicago, according to NPR. “Some hundred million years later, the modern mammals re-evolved this gliding adaptation several times over.”

Modern winged mammals glide using areas of skin membrane that stretches out between their fore and hind limbs. While the fossils exhibited that trait, they also had a wide range of other strange characteristics. This included fused wishbones like the ones found in birds, and shoulder girdles, which are common in modern day marsupials.

Today’s gliding mammals include North American flying squirrels, the flying lemurs of Southeast Asia, gliding marsupials in Australia, and the rodent gliders of Africa. While researchers are not sure why the trait evolved in the way that it did, it likely came about as a way to move around the treetops without being threatened by predators lurking on the ground.

The new fossils show that mammals were more diverse during the age of the dinosaurs than previously believed. They also reveal that there was an evolutionary explosion during the Jurassic period. Researchers hope to further study remains from that time to see what other adaptations came about during that time.

“We think of the Jurassic as ‘dinosaur world,’” said Roger Benson, a researcher at Oxford University who was not involved in the study, told BBC News. “But fossils keep showing us the great diversity of small mammals doing many of the ecological jobs they do today.”