Dinosaur feathers were for show, not flying, study reveals

Published on Wednesday 27 January 2010 21:57

FEATHERS may have originally evolved in dinosaurs as brightly coloured ornaments, scientists believe.

Only later did they develop into insulation material and flight structures, research suggests.

The evidence comes from the first dinosaur to have its colouring identified, a flesh-eating creature with a racoon-like orange and white tail.

Sinosauropteryx, which stood on two legs and was the size of a small dog, had an early version of feathers in the form of simple bristles 4mm to 10mm in length, an electron microscope revealed.

Professor Mike Benton, from the University of Bristol, who worked with colleagues from China on the research, said: "Our research provides extraordinary insights into the origin of feathers. In particular, it helps to resolve a long-standing debate about the original function of feathers – whether they were used for flight, insulation or display.

"We now know that feathers came before wings, so feathers did not originate as flight structures.

"We therefore suggest that feathers first arose as agents for colour display and only later in their evolutionary history did they become useful for flight and insulation."

In birds, bright colours were always associated with display – an extreme example being the tail of the peacock, Prof Benton told a news conference in London.

Displayed colours could be used to attract mates, or to frighten off rivals or predators.

"From the fact that Sinosauropteryx has, we believe, a stripy tail, we would say that's a display function," said Prof Benton. "It's clearly not for flight, because these are just short bristles.

"It's between insulation and display; what came first, we're not quite sure.

"What we don't know is how substantially the body was covered in feathers. The whole body may have been covered in feathers or maybe not. If it was not, then display is the primary purpose."