Tiny Version of T. Rex Discovered

Paleontologist Paul Sereno adds the toe claw to a well-preserved skeleton of the Raptorex, which means "king raptor." (Mike Hettwer / Getty Images)

Tiny version of T. rex discovered

Scientists say 9-foot Raptorex was small blueprint of later animal
Randolph E. Schmid / Associated Press

Washington -- About 125 million years ago a tiny version of Tyrannosaurus rex roamed what is now northeastern China. Tiny, that is, by T. rex standards -- you still wouldn't want to meet it face to face. The creature was what Austin Powers might call T. rex's Mini-Me. This early predator stood about 9 feet tall. It just seems small compared to the giant T. rex that evolved millions of years later and was as much as 100 times more massive.

"It really is the blueprint for the later (T. rex) dinosaurs," paleontologist Paul Sereno said. "It was a blueprint that was scalable." The new animal, based on a single fossil smuggled out of China and eventually sold to a private collector, has been named Raptorex, which means "king raptor."

It was described for the first time in Thursday's ScienceExpress, the online edition of the journal Science. Sereno reports that Raptorex has all the hallmarks of T. rex, including a large head, tiny arms and lanky feet -- just in a smaller size. "What we're looking at is a blueprint for a fast-running set of jaws," Sereno said at a briefing arranged by the American Association for the Advancement of Science.

Like T. rex, Raptorex had a bite force so powerful it could chomp through bone. The giant T. rex dominated much of the planet from about 90 million years ago until the great extinction 65 million years ago.

Raptorex would have weighed only about 150 pounds, said Sereno, of the University of Chicago and also a National Geographic explorer in residence.

The newly described remains were found by fossil hunters in northern China, smuggled out of that country and offered for sale to collector Henry Kriegstein of Higham, Mass., Sereno said. Kriegstein donated the materials to science, and they will be returned to China. The fossil was encased in a single block of stone, Sereno said. That stone allowed the researchers to trace the find to its original location.

The way the bones were fused indicates the animal died at the age of 5 or 6, which is nearly adult. It would have matured at 8 or 10 and been old by 20, added co-author Stephen Brusatte of the American Museum of Natural History. The find also shows that features such as the animal's tiny arms did not evolve as T. rex grew larger, but were present in the much earlier forms, Brusatte said.

"Much of what we thought we knew about T. rex turns out to be simplistic or out-and-out wrong," Brusatte said. Sereno said Raptorex was a predator. Some scientists debate whether T. rex was a predator or scavenger.

The Washington Post contributed