November 4, 2009

Scientists Discover Oldest Known T. Rex Ancestor

Scientists have uncovered new clues about the early stages of the Tyrannosaurus rex's beginnings.

A team of British and German researchers studied a fossil held at London's Natural History Museum. They have concluded that the remains, which belong to a dinosaur named Proceratosaurus, may be the earliest known relative of the T. rex.

Scientists say Proceratosaurus roamed the earth about 165 million years ago, during the middle Jurassic Period. He stood on two legs, was carnivorous, and would have weighed up to 60kg.

Dr. Oliver Rauhut from LMU Munich and Dr. Angela Milner from the Natural History Museum London said the fossil was initially misclassified, but was later recognized to belong to a previously unknown genus, which was named Proceratosaurus.

Proceratosaurus is the earliest known ancestor of the family Tyrannosauridae, of which the T. rex belongs to.

"This is a unique specimen. It is the only one of its kind known in the world," Dr Milner told BBC News.

"It was quite a surprise when our analysis showed we had the oldest known relative of T. rex."

"Fossils collected a century ago can now be studied again with the benefit of much greater knowledge of dinosaurs from around the world."

"It is quite astonishing that this fossil has received so little attention, since it is one of the best preserved dinosaur skulls in Europe," said Rauhut.

Researchers used computerized tomography (CT) scans of the fossilized skull at a lab in Texas.

"Computerized tomography is a wonderful method, because it offers us a non-destructive means of visualizing the internal structures of fossils," said Milner.

The CT scan showed that Proceratosaurus carried similar cranial features to that of the T. rex, despite the fact that the skull is about 100 million years older and mch smaller.

"The skull became more robust and the jaw muscles larger and, overall, the body increased enormously in size," said Rauhut. "Proceratosaurus also confirms that the tyrannosauridae developed over a very long stretch of time, and gave rise to a great diversity of forms. Further members of the family surely await discovery."


On the Net: