Primitive T. Rex Ancestor Unearthed in China

Digging near Chinese badlands that appeared in the movie “Crouching Tiger, Hidden Dragon,” scientists have found their own hidden dragon: the oldest known tyrannosaur, a primitive ancestor of the fearsome Tyrannosaurus rex.

The two skeletons they unearthed shed light on the lineage that produced T. rex, revealing a creature that lived 160 million years ago. That’s about 90 million years before T. rex came along.

A two-legged meat-eater with a crest on its head, the beast was far smaller than its celebrity descendant, measuring about 10 feet from its snout to the tip of its tail and standing about 3 feet tall at the hip. It also sported relatively long three-fingered arms, rather than the two-fingered stubby arms T. rex had. Scientists suspect it had feathers because related dinosaurs did.

The big surprise, said study coauthor James Clark of George Washington University in Washington, D.C., was the finding of a narrow, delicate, largely hollow crest on its head. Though other dinosaurs had similar features, this one was unusually large and elaborate for a two-legged meat-eater, Clark and coauthors wrote in the current issue of the journal Nature.

Nobody knows the crest’s purpose, but it was probably some kind of display to other members of its own species, said Clark, co-leader of 2002 expedition that found the fossils.

The researchers named the creature Guanlong wucaii, from the Chinese words for “crown” and “dragon,” referring to the crest, and for “five colors,” from the multihued badlands where the creature was found.

Because it preserves anatomical features from its ancestors that were lost in T. rex and other tyrannosaurs, the primitive creature might help scientists understand where tyrannosaurs fit in the evolutionary tree.

“This is the best look so far at the ancestral condition from which the tyrant dinosaurs, T. rex and company, evolved,” said the expert, Thomas Holtz Jr. of the University of Maryland.