New evidence found to dinosaurian hypothesis of bird origins

Fossils found recently in northwest China's Xinjiang region of a new dinosaur species with a unique cranial crest might be the earliest ancestor of a line that culminated in the tyrannosaurus rex, Monsters and Critics.com quoted scientists as saying. The discovery, carried out by eight researchers from China, the United States and Canada, is published on the Feb. 9 issue of US science magazine Nature.

The two fossils discovered are believed be of a 3-metre tyrannosaur that lived in the Late Jurassic period about 160 million years ago, according to lead researcher Xu Xing from the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, who says the fossils provide new clues on the evolution of birds from carnivorous dinosaurs.

The previous earliest fossil of a tyrannosaur, some of which are believed to have developed feather-like scales that evolved into birds' plumage, was dated to the Cretaceous period, which followed the Jurassic.

The scientists said the dinosaur's apparently inflatable crest, which is depicted in a Nature graphic as something like a horizontally flattened rhinoceros horn, was its 'most spectacular' and surprising feature.

"The crest on the nose of the tyrannosaurus is huge, delicate and fragile, which is believed to be a unique phenomenon in the dinosaur species," said Xu.

"For a ferocious predator, it is dangerous to have such a crest, but the phenomenon is a sexually selected trait, which has an importance to the existence of the species," he added.

Xu said the scientists believe the crest might have been used for attracting mates, for mutual recognition and perhaps for producing sound.

By People's Daily Online