It's as long as a school bus, weighs over a ton and has terrifying dagger-like teeth to devour its prey. That's the sort of tyrannosaur we all know, but did you know it was fuzzy? New specimens dug up in northeastern China yield a surprising discovery.
Three fossilised tyrannosaurs found in China's Liaoning province, one adult and two juveniles, are estimated to be around 125 million years old, having roamed in the early Cretaceous period. A distant relative of the familiar Tyrannosaurus Rex, the new dinosaur is named Yutyrannus Huali, a combination of Latin and Mandarin Chinese meaning beautiful feathered tyrant.
That name comes from the stunning display of soft, down-like feathers that patched the dinosaurs' skin in the fossils. Given the patches appearing on seemingly random parts of the three specimens - though namely the hips, feet and forelimbs - it's speculated with confidence that Yutyrannus Huali wore a full shaggy coat.
Finding feathers on a dinosaur is no new thing, though. It's been long-known already that many dinosaurs had feathers, but it's been a common assumption so far that only the smaller predatory theropods, which evolved into birds, had feathers. Yutyrannus Huali is the largest feathered dinosaur to ever be discovered, and completely rids the assumption of feathers being restricted to smaller dinosaurs. In fact, it's 40 times larger than the previous record-holder for largest known feathered dinosaur.
"It was quite clear we had something impressive." says Corwin Sullivan, a vertebrate paleontologist who's been studying the new dinosaur.
These aren't the feathers that we see on adult birds today, however. They had no purpose in flight. The temperature in the region at the time is estimated to have been around 10 degrees Celsius, and the thin fuzzy hair-like feathers of the dinosaur would have made excellent insulation to protect against the cold. The feathers ranged from 6 to 8 inches in length.
"They were more like the fuzzy down of a modern baby chick than the stiff plumes of an adult bird," says Xing Xu, researcher at the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing.
Another possible use of the feathers was for displaying to potential mates, in a similar fashion to peacocks. Furthermore, a startling feature about this dinosaur is the rippled crest that runs along the top of Yutyrannus Huali's skull. Xu noted that the crest also could have been used to attract a mate. The close proximity of the specimens shows that these could have been very social animals that hunted in packs.
Although living in a colder region and 50 million years before Tyrannosaurus Rex, its larger relative, there's little reason to say Tyrannosaurus Rex couldn't have had similar feathers, too. A stark contrast to the Hollywood image of the ferocious scale-skinned T. Rex, but a possibility nonetheless.
Xing Xu leads the research team that studied the fossils meticulously in order to make sure their findings were accurate. A problem posed to them is that the fossils were not excavated professionally, but rather found by collectors. Therefore little is known about the environment from which the fossils came.
Thomas Holtz, a paleontologist at the University of Maryland, explains, "When these commercial collectors go after the stuff like trophies, they're missing all that other context that can help us answer so much else about the world of dinosaurs."
Regardless, the specimens remain especially lucky finds in that they were found almost completely intact. "Finding a complete articulated skeleton of a large dinosaur is fairly rare, and here there are three almost complete skeletons found. That's pretty amazing.", said Holtz.