So maybe the ancestors of these dinosaurs had feathers and lost them. But Benton points out that many mammals, from whales to elephants, have lost most of their hair. The counterargument is that many giant dinosaurs had armour rather than feathers. “That would take the origin back from about 170 million years ago to around 250 million years,” says Benton. Or they evolved in the common ancestor of all these groups. Either very similar looking feathers evolved independently on at least four occasions: in pterosaurs, in theropod dinosaurs such as velociraptors (which gave rise to birds) and in two groups of plant-eating ornithischian dinosaurs represented by Psittacosaurus and Kulindadromeus. “I think it’s now case closed, pterosaurs had feathers.” “If all I had was a photo of the fluffy stuff on these fossils, and I didn’t know they were attached to a pterosaur, I would probably think they were the feathers of a feathered raptor dinosaur,” says palaeontologist Steve Brusatte of the University of Edinburgh in the UK, who wasn’t involved in the study. They are remarkably similar to the feathers found on many dinosaurs. And the third, found on the wing membranes, branches from the base and resembles down. The second type, found on the head, has side branches. One type, found on the neck, branches at the end in a brush-like manner.
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