The flying reptiles, pterosaurs, had four kinds of feathers which they shared with dinosaurs -- pushing back the origin of feathers by 70 million years, according to a study.
It was presumed that pycnofibres were fundamentally different to feathers of dinosaurs and birds, they said.
The study, published in the journal Nature Ecology & Evolution, shows that pterosaurs had at least four types of feathers.
These four types are now also known from two major groups of dinosaurs -- the ornithischians, which were plant-eaters, and the theropods, which include the ancestors of birds.
"We went to Inner Mongolia to do fieldwork in the Daohugou Formation," said Baoyu Jiang from Nanjing University in China.
"We already knew that the sites had produced excellent specimens of pterosaurs with their pycnofibres preserved and I was sure we could learn more by careful study," Jiang said.
Some critics have suggested that actually there is only one simple type of pycnofibre, but our studies show the different feather types are real, researchers said.
"We focused on clear areas where the feathers did not overlap and where we could see their structure clearly," said Maria McNamara from the University College Cork in Ireland.
"They even show fine details of melanosomes, which may have given the fluffy feathers a ginger colour," said McNamara.
The researchers ran some evolutionary analyses and showed clearly that the pterosaur pycnofibres are feathers, just like those seen in modern birds and across various dinosaur groups.
"Despite careful searching, we couldn't find any anatomical evidence that the four pycnofibre types are in any way different from the feathers of birds and dinosaurs," said Professor Mike Benton from the University of Bristol.
"Therefore, because they are the same, they must share an evolutionary origin, and that was about 250 million years ago, long before the origin of birds," he said.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)