Birds are famous for their colorful feathers, which they use to fly, flirt and keep warm. But long before avians ever flapped their wings, flying reptiles called pterosaurs seized the skies.

Among paleontologists, it was a long-running assumption that the winged creatures lacked feathers. But a team of researchers has found what they believe to be tiny structures hiding in the fossils of two pterosaurs from China that they say are feathers — not as elegant, but comparable to the plumage on birds and dinosaurs.

More specimens may be needed to confirm the finding, which other paleontologists questioned. But if true, it would push back the origins of feathers by about 70 million years, and also be the first time that feathers have been identified on an animal that was neither a bird nor a dinosaur.

“The feather has deeper origins, not of a bird but maybe from the ancestors of birds, dinosaurs and pterosaurs,” said Baoyu Jiang, a paleontologist from Nanjing University in China and leader of the team that collected the fossils. Their research was published Monday in the journal Nature Ecology & Evolution.