Huge feathered dinosaur identified
A "shaggy" close cousin of Tyrannosaurus rex discovered in China is
the biggest feathered dinosaur known, scientists have revealed.
Yutyrannus huali measured almost 30 feet and weighed more than a
tonne. Like T. rex it was a formidable predator, but - unlike its famous
relative - was covered in downy feathers. Scientists believe the
feathers had no connection with flight and would have been used to keep
the animal warm.
Despite being dwarfed by T. rex, Yutyrannus was 40 times heavier than
the largest feathered dinosaur known to date, Beipiaosaurus. Three
almost complete fossil skeletons of Yutyrannus, one adult and two
juveniles, were found in Liaoning Province, north east China. Its name
is a combination of Latin and Mandarin meaning "beautiful feathered
tyrant". Isolated patches of preserved skin from T. rex suggest that it
was covered in scales rather than feathers.
But Yutyrannus, which like T. rex walked on two legs, showed clear
evidence of primitive plumage.
"The feathers of Yutyrannus were simple filaments," said Professor Xu
Xing, from the Chinese Academy of Sciences in Beijing, whose team
described the find in the journal Nature. "They were more like the fuzzy
down of a modern baby chick than the stiff plumes of an adult bird."
T. rex lived in the warm Late Cretaceous period, which ended when the
dinosaurs went extinct 65 million years ago. Yutyrannus, on the other
hand, dates back to the cooler Early Cretaceous. Its feathers probably
provided insulation, despite the animal's large size, scientists
"The idea that primitive feathers could have been for insulation
rather than flight has been around for a long time," said co author Dr
Corwin Sullivan, a Canadian palaeontologist based at the Chinese Academy
"However, large-bodied animals typically can 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
Prof Xu said Yutyrannus dramatically increased the size range of
feathered dinosaurs.He added: "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." - PA