It's a bird. It's a plane. It's a Jurassic mammal!

Not all prehistoric mammals needed to scurry to avoid dinosaurs with whom they shared the planet in the Jurassic age. Some just glided, according to research published Thursday.

Fossils of two extinct mammals that lived in China some 160 million years ago, revealed the outlines of wing-like membranes joining the rodent-like critters' front and hind limbs, scientists wrote in the journal Nature.

"With long limbs, long hand and foot fingers, and wing-like membranes for tree-to-tree gliding, Maiopatagium furculiferum and Vilevolodon diplomylos are the oldest known gliders in the long history of early mammals," said a statement form the University of Chicago, whose researchers took part in the study.

One of the critters measured about 23 centimetres (nine inches) from head to tail, and the other 8 cm without its tail, which was missing.

Their gliding ability would have given them access to food that land-bound competitors could not reach, said the team.

This showed that ancestral mammals adapted to a challenging environment and tough competition from dinosaurs.

"These new fossil gliders are the first winged mammals and they demonstrate that early mammals did indeed have a wide range of ecological diversity," said the team.

This "means dinosaurs likely did not dominate the Mesozoic landscape as much as previously thought."

The Mesozoic era from about 250 million to 66 million years ago was divided into the Triassic, Jurassic and Cretaceous periods.