LONDON (Reuters) - Chinese and American scientists have unearthed a fossil of a small, feathered, flightless dinosaur in northern China which they say is definitive proof that feathers originated before birds or flight.
"This is a significant chunk adding to the greater body of all the evidence we have, which I think by any standard of doubt is definitive that feathers aren't for flight, that non-avian dinosaurs had feathers and that birds are a kind of dinosaur," Mark Norell, of New York's American Museum of Natural History, said in an interview.
Norell and scientists from the Chinese Academy of Geological Science in Beijing reported their finding in the science journal Nature on Wednesday.
They said the feathers covered the creature, a dromaeosaur -- a small, fast running two-legged predator which scientists believe shares a close common ancestor with birds.
Paleontologists have found evidence of fluff or fuzz on other ancient creatures but this is the first evidence of feathers in a dromaeosaur, thought to be one of the closest relatives of birds.
Scientists have been divided over whether birds evolved from dinosaurs or independently from some earlier, yet undiscovered reptile, but Norell thinks the latest finding may resolve any lingering doubt because the feathers of BPM 1 3-13 are structurally identical to those of modern birds.
"The presence of modern feathers on this new dromaeosaur shows definitively that they evolved in dinosaurs before the emergence of birds and flight, and that therefore feathers are not an adaptation for flight," Norell explained.
Dromaeosaurs belong to a group of dinosaurs called theropods which share about 100 anatomical features, including a wishbone, swiveling wrists and three forward-pointing toes, with birds.
Norell said the downy primitive feathers of Archaeopteryx, the earliest known bird which lived 150 million years ago, and the feathers of BPM 1 3-13 probably have a common evolutionary origin.