Largest-ever feathered dinosaur discovered in China

Scientists have discovered a new species of dinosaur, the largest-ever feathered dinosaur, in northeast China's Liaoning Province.

A statement released by the Institute of Vertebrate Paleontology and Paleoanthropology under the Chinese Academy of Sciences on Thursday said that the new species is a close relative of the Tyrannosaurus rex. Its name "Yutyrannus huali," is a combination of Latin and Chinese and means "beautifully feathered tyrant."

Fossils previously discovered in the province have indicated that some small dinosaurs had bird-like feathers, whereas three fossil specimens of the new tyrannosauroid from the same region show that at least one much larger dinosaur had a feathery coat as well, the statement said.

Chinese and Canadian scientists also published the new discovery in this week's issue of the journal Nature.

The Yutyrannus is believed to have lived during the Early Cretaceous period around 125 million years ago.

"The feathers of Yutyrannus were simple filaments," said Professor Xu Xing, research fellow at the institute and the lead author of the study. "They were more like the fuzzy down of a modern baby chick than the stiff plumes of an adult bird."

The researchers estimate that an adult Yutyrannus would have been about 9 meters long and weighed about 1,400 kg. This makes it considerably smaller than the Tyrannosaurus rex, but some 40 times the weight of the largest previously known feathered dinosaur, the statement said.

The large size of Yutyrannus and the downy structure of its feathers would have made flight an impossibility, the statement continued, but the feathers may have had another important function--insulation to keep warm.

"The idea that primitive feathers could have been for insulation rather than flight has been around for a long time," said Dr Corwin Sullivan, a Canadian palaeontologist involved in the study. "However, large-bodied animals typically retain heat quite easily, and actually have more of a potential problem with overheating. That makes Yutyrannus, which is large and downright shaggy, a bit of a surprise."

According to the statement, the explanation may be climate-related.

While the Cretaceous Period was generally very warm, Yutyrannus lived during the middle part of the Early Cretaceous, when temperatures are thought to have been somewhat cooler.

"Yutyrannus dramatically increases the size range of dinosaurs for which we have definite evidence of feathers," Xu said. "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."