From Washington Post
Mammals may have taken to the skies much earlier than previously believed, according to research published last week in Nature.
Paleontologists have recovered a fossil of a previously unknown bat- or squirrel-size creature that lived in Mongolia about 125 million years ago. It bears evidence that a skin membrane stretched between the animal's front and rear limbs, providing enough lift for it to glide through the air. The creature, which weighed less than a pound, also apparently had a long, stiff tail that could be used like a rudder in flight, researchers found.
The animal, which is not a direct ancestor of flying squirrels, bats or any other living mammals, lived tens of millions of years before the earliest confirmed record of bats taking wing about 51 million years ago. Before now, the earliest known gliding mammal, a rodent, lived 30 million years ago.
The research, led by Jin Meng, associate curator at the American Museum of Natural History's division of paleontology, shows that there was greater diversity among early mammals than scientists had thought. Indeed, the fossil's discovery points to the existence of an entirely new group of mammals, researchers said.
"This new evidence of gliding flight in early mammals is giving us a dramatically new picture of many of the animals that lived in the age of the dinosaurs," Meng said.