Friday, March 26, 2010

Tyrannosaurs spread worldwide early in Age of Dinosaurs

Paleontologists Thursday unveiled the first fossil evidence -- a foot-long pelvic bone found in Australia -- showing that T. Rex's predecessors roamed the entire globe.

Reported in the journal, Science, the 110 million-years-old fossil pubis is "almost identical to those of tyrannosaurids", says the study led by Roger Benson of the United Kingdom's University of Cambridge.

The finding of the bone -- crucial for the balance of the distinctive carnivore's shape -- suggests that "advanced tyrannosaurids" flourished tens of millions of years before T. Rex evolved to colossal size around 85 million years ago to become the top predator of the dinosaur world, say the report authors. These dinosaurs would have been long-legged with little arms and thick skulls. The fossil also shows a relation to smaller, fleeter Raptorex dinosaur carnivores from even earlier dinosaur eras.

"The find is intriguing and certainly suggests tyrannosaurids flourished worldwide," says paleontologist Thomas Holtz of the University of Maryland in College Park, who was not part of the study. But Holtz cautions that more than just one bone is needed to confirm the worldwide extent of T. Rex's predecessor.

No comments: