Get to Know a Dino: Yutyrannus huali

by AMNH on

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The first fossil of Yutyrannus huali, a primitive cousin of the more famous Tyrannosaurus rex, was discovered in 2012 in Liaoning Province, China. Among the specimen’s amazing features were clearly preserved proto-feathers—early structures that predate the feathers of modern birds. Similar structures have been found on all three specimens discovered so far, showing that in life, Yutyrannus rocked a shaggy proto-feather coat.

Model of a dinosaur with short arms, long tail, and open mouth full of sharp teeth, covered in two-toned hair from the neck to tail.
A Yutyrannus model in Dinosaurs Among Us.
Roderick Mickens/© AMNH

You can see a cast of one of these fossils, along with a life-sized model of the dinosaur, at Dinosaurs Among Us, open now. 

Yutyrannus fossil cast mounted on a wall in 12 separate pieces.
A cast of a Yutyrannus huali fossil.

Feathers, Not Flight: In life, Yutyrannus huali probably weighed in at about 1.5 tons, making it the largest theropod dinosaur discovered so far that shows direct evidence of proto-feathers. At that weight, it would have been much too heavy to take to the air, but paleontologists think its entire body was probably covered in this primitive plumage.

Dinosaur Dating Game: So what purpose did feathers serve on this titanic tyrannosaur? Remember that feathers aren’t just for flight—they serve a number of functions in modern birds, from helping animals stay warm to attracting mates. Yutyrannus wasn’t ready to fly, but researchers think its plumage may have played a role in courtship rituals.

What About T. rex?

Yutyrannus may have been a “beautiful feathered tyrant,” as its name suggests, but what about its royal relative, Tyrannosaurus rex? Turns out this iconic dinosaur probably had feathers as well. A juvenile T. rex likely had a thin, downy coat of feathers, while adults may have used their plumage for display.

Want to learn more about Dinosaurs Among Us? Check out this video introduction detailing the transition from ancient dinosaurs to modern birds.