Dinosaurs may have evolved feathers for courtship

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Fossils of a feathered dinosaur have given wings to the idea that complex quilled feathers might have evolved for courtship, not flight, in at least one dinosaur species.


The species concerned, the ostrich-like Ornithomimus, seems to have had vaned feathers but neither it, nor its ancestors, ever seem to have taken to the air.

The new insights come from re-examination of a series of fossils found in North America. After finding two fossils in stream-bed deposits in Alberta, Canada, one in 2008 and the other in 2009, a local businessman contacted University of Calgary palaeontologist Darla Zelenitsky.

Technicians at the Royal Tyrrell Museum in Midland Provincial Park, Alberta, then exposed filamentary feathers on the Ornithomimus remains as they removed the rock encasing the bones.

That discovery led them to check an adult Ornithomimus discovered in 1995 that had odd marks on its forearms. “We went back and found the traces on the forearms looked like marks left by the vaned feathers of modern birds,” Zelenitsky says.

Feathers with central vanes or shafts are required for flight, but ornithomimids were bipedal dinosaurs and grew to 3.5 metres long – far too large to fly. Falling between two feathered groups, birds and tyrannosaurs, on the evolutionary tree, they are not thought to have had flying ancestors.

Ornithomimids split from the evolutionary branch of birds long before flight evolved, so palaeontologists expected ornithomimids to have downy or filamentary feathers like tyrannosaurs.

Written By: Jeff Hecht
continue to source article at newscientist.com

5 COMMENTS

  1.   Whatever their purpose, evolution preserved them for some 80 million years from the time ornithomimids evolved (about 155 million years ago) until the dinosaurs in the area died 70 million to 75 million years ago.

    It is well established that feathers evolved on various groups of dinosaurs, long before they became adapted for flight.

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