By YAHOO
Added: Thu, 08 Nov 2007 00:00:00 UTC

Thanks to TrashcanMan79 for the link.

Reposted from:
http://news.yahoo.com/s/afp/20071107/sc_afp/sciencepalaeontologydinosaurs_071107194932;_ylt=A9j8e9b7YzJHzR8BSwAE1vAI

PARIS (AFP) - Small, fast-moving carnivorous dinosaurs had air-sac respiratory systems similar to modern-day penguins and other diving birds, scientists reported on Wednesday.

Palaeontologist Jonathan Codd of Britain's University of Manchester studied the fossilised remains of so-called maniraptoran dinosaurs and extinct birds, including the pioneering avian known as Archaeopteryx.

His team found that key structures used for breathing know as uncinate processes -- present in some modern birds -- could also be found in both sets of samples.

The uncinate processes are small bones that act as levers to move the ribs and sternum during breathing.

These bones differ in length according to the bird -- they are shortest in running birds, of intermediate length in flying birds, and longest in diving birds.

"The dinosaurs we studied from the fossil record had long uncinate processes similar in structure to those of diving birds," the university quoted Codd as saying in a press release.

"This suggests both dinosaurs and diving birds need longer lever arms to help them breathe."

The finding also implies that running dinosaurs such as the famous Velociraptor had efficient respiratory systems, swiftly providing them with the oxygen they needed when running after prey.

The study underpins previous research that says birds evolved from dinosaurs.

It appears in Proceedings of the Royal Society B, a journal of the Royal Society, which is Britain's de-facto academy of sciences.

TAGGED: EVOLUTION, PALEONTOLOGY