April 5, 2012
New Dinosaur Species Is Largest Known Feathered Animal
A new species of giant, feathered dinosaur discovered in northeastern China is the largest known feathered animal —- living or extinct -- ever to have existed, scientists reported on Wednesday.
Xing Xu and from the Chinese Academy of Sciences in Beijing and colleagues discovered three nearly-complete skeletons of the dinosaur, named Yutyrannus huali, meaning "beautiful feathered tyrant", in beds of sediment in Liaoning province. The meat-eating creatures, known as Tyrannosauroids, were relatives of Tyrannosaurus rex. They lived about 125 million years ago and weighed as much as a car.
"Yutyrannus dramatically increases the size range of dinosaurs for which we have definite evidence of feathers," said Xu.
"It's possible that feathers were much more widespread, at least among the meat-eating dinosaurs, than most scientists would have guessed even a few years ago."
The discovery challenges current theories about the evolution of T.rex and its cousins, which lived until around 65 million years ago when they were wiped out by giant asteroids. Until now, earlier relatives of these dinosaurs were believed to have been much smaller in size.
The fossils include a one-and-a-half-ton adult and two juvenile specimens, which share some features with later tyrannosaurs such as T.rex, but have three functional fingers (T.rex had two) and a foot more similar to those of other early tyrannosaurs.
Perhaps the most remarkable discovery is Yutyrannus´ extensive plumage, which provides direct evidence of the existence of giant feathered dinosaurs. The researchers believe the long, filament-like feathers would have acted as insulation, although they may have been used for mating or fighting rituals.
The remarkably preserved fossils of Yutyrannus came from the Yixian Formation in Liaoning, which has been a treasure trove of dinosaurs. Discoveries made in the area have supported the theory that modern birds are the descendants of small feathered theropods that took to the trees for food or safety, and later learned to glide or fly.
The current findings were reported in a paper published on Wednesday in the journal Nature. A summary can be viewed here.
Image Caption: Artist´s impression of a group of Yutyrannus and two individuals of the smaller Beipiaosaurus. Credit: Dr Brian Choo/Chinese Academy of Sciences