Dr. Brian Choo/Nature
An artist's impression of a group of Yutyrannus. The 30-foot-long dinosaurs were covered with downy feathers — likely to keep the animals warm.
Thirty feet long and weighing in at around 3,000 pounds, Yutyrannus huali goes by the nickname "beautiful feathered tyrant." Yutyrannus earned the name "tyrant" because it casually ripped its prey to pieces. But it was also a snappy dresser: The huge predator was covered in downy feathers.
"Cuddly" and "dinosaur" may not seem like they belong in the same sentence — the beast was a close cousin of T rex, not quite as big but certainly able and happy to devour anything it wanted to — but the fossil skeletons of three of these animals were indeed feathery.
The new-to-science dinosaurs amazed paleontologist Corwin Sullivan when he first saw them. Their feathers were primitive, more like filaments, and about 7 inches long.
"The most plausible explanation, I think, is that most or perhaps virtually all of the body was covered," Sullivan says.
Back in the day — about 125 million years ago — there were other feathered dinosaurs, but they were the size of turkeys. Yutyrannus was no turkey.
Why feathers? A flying Tyrannosauroid would no doubt have been awesomely terrifying. But Yutyrannus didn't fly. Sullivan and his colleagues at the Chinese Academy of Sciences suspect the feathers kept the animal warm. It was cooler during that period than in the days of T rex, who lived tens of millions of years later.
There's no indication what color the feathers were, but in the scientists' research paper, published in the journal Nature, an artist's rendition (seen above) shows a sort of plume along the crest of the head — a kind of punk look. The rest of the body is more of a '60s-style shag rug.
"They would have looked like hair or bristles or the downy feathers on a chick," Sullivan says. "A bit like shaggy monsters."
Like a warm and fuzzy Tyrannosaurus? "Well, lots of predators are warm and fuzzy in a sense," Sullivan says. "Think of a grizzly bear or something."