Oldest T. Rex relative unveiled|davinian|cfz@davinian.co.uk|02/09/06 at 08:25:54|davinian|xx|0|82.35.173.13|[b]Oldest T. Rex relative unveiled[/b]

[b]The forefather of the mighty Tyrannosaurus rex has been discovered, scientists report.[/b]

The 160 million-year-old fossil is the oldest tyrannosaur ever found.

The researchers were surprised to learn the 3m long dinosaur sported a spectacular feathered crest on its head which may have been brightly coloured.

The discovery, unveiled in the journal Nature, might reveal how early tyrannosaurs evolved into the T. rex 100 million years later.

The new species was found in the Junggar Basin, an area rich in dinosaur fossils, in the far north-west corner of China.

[b]'Crowned dragon'[/b]

A local labourer, hired to search for ancient bones, happened upon two dinosaur skeletons: a 12-year-old adult and a six-year-old juvenile. Both were found to be remarkably intact.

The international team have named the dinosaur, which hails from the Late Jurassic period, Guanlong wucaii (G. wucaii) which is derived from the Chinese for "crowned dragon".

Professor James Clark, an author on the paper and a palaeontologist at George Washington University, US, told the BBC News website of the discovery.

"We found two skeletons of what we call a therapod dinosaur. When we looked at them very closely we found that they are a relative of Tyrannosaurus rex - making them the most primitive tyrannosaur relatives that we have seen," he explained.

Tyrannosaurs were the dominant group of predators during the Late Cretaceous period. This era, about 65 to 100 million years ago, marked the final chapter before dinosaurs became extinct.

It was during this time the T. rex roamed. The most famed member of the tyrannosaur family; its immense size of between 9 to 13m, huge teeth and tiny but savagely-clawed forearms have made it the beast of choice for many Hollywood films.

[b]Evolution clues[/b]

Professor Clark described how the G. wucaii would have looked: "The most obvious thing was that it had a big crest in the middle of its head. For carnivorous dinosaurs that's pretty unusual.

"We suspect that the crest was highly coloured and probably a display structure of some kind."

He said that it shared some features with the later tyrannosaurs, such as the T. rex. It had sharp teeth, relatively short forelimbs with claws, and probably ran on two legs.

But the G. wucaii differed markedly in terms of its size: at three metres it was much smaller. In addition, its more primitive skull and pelvic features would suggest that that it was intermediate animal between tyrannosaurs and the coelurosaurs - an even older related group of dinosaurs which are also the predecessors to modern birds.

The researchers hope that the find will reveal more about the primitive phase of tyrannosaur evolution.

"Guanlong shows us how the small coelurosaurian ancestors of tyrannosaurs took the first step that led to the giant T. rex almost 100 million years later," Prof Clark said.

Most of the tyrannosaur fossils that have been found date to the latter years of tyrannosaurs' existence, and there are very few early specimens.

Prior to the discovery of the G. wucaii, the 130 million-year-old feathered Dilong paradoxus (D. paradoxus) reported in 2004, was the oldest tyrannosaur known.

Dr Paul Barrett, a palaeontologist at the Natural History Museum, commented: "The discovery of this new animal pushes the origin of the group containing T. rex further back in time and also shows that early tyrannosaurs had a much wider distribution than previously thought."

The researchers believe the G. wucaii, with its bizarre crest, will begin to fill in some of the gaps of our knowledge of tyrannosaurs.

"This is 160 million years old, there are almost 100 million years of fossil records between it and T. rex and there are only a few tyrannosaurs that we know of between that," said Professor Clark

"It is telling us that we are just getting into finding the missing records of these early tyrannosaurs."

Story, [url=http://news.bbc.co.uk/1/hi/sci/tech/4692962.stm]BBC[/url].|| Re: Oldest T. Rex relative unveiled|Ed Malone|cfz@eclipse.co.uk|02/09/06 at 08:26:55|obadiah|xx|0|86.131.87.233|Early Version of T. Rex Is Discovered

By MALCOLM RITTER, AP Science Writer

Wed Feb 8, 6:10 PM ET

NEW YORK - Scientists say they've found the earliest known tyrannosaur, shedding light on the lineage that produced the fearsome Tyrannosaurus rex. The discovery comes with a puzzle: Why did this beast have a strange crest on its head?

Digging in the badlands of northwestern China that appeared in the movie "Crouching Tiger, Hidden Dragon," researchers found two skeletons of a creature that lived some 160 million years ago. That's more than 90 million years before T. rex came along.

A two-legged meat-eater, the beast was far smaller than T. rex, 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 discovery is reported in Thursday's issue of the journal Nature.

The big surprise, said study co-author James Clark of George Washington University in Washington, D.C., was the finding of a narrow, delicate, largely hollow crest on its head. While other dinosaurs have had similar features, this one was unusually large and elaborate for a two-legged meat-eater, Clark and co-authors wrote.

Nobody knows its 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 beast.

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 multi-hued 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 beast helps scientists understand where tyrannosaurs fit in the evolutionary tree, said an expert not involved in the discovery.

"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.

Along with some other finds, the creature helps illustrate the sequence of anatomical changes that occurred along the way to the later, more specialized tyrannosaurs, said Philip Currie of the University of Alberta in Canada.

Ken Carpenter, curator of lower vertebrate paleontology at the Denver Museum of Nature and Science, said he tentatively accepts the creature as a tyrannosaur but isn't convinced of its age. It could be much younger, he said. Clark said that other data, not yet published, support the proposed age of 160 million years.

___

On the Net:

Nature: http://www.nature.com/nature

Background on tyrannosaurs:

http://www.ucmp.berkeley.edu/diapsids/saurischia/tyrannosauridae.html

|| Re: Oldest T. Rex relative unveiled|Ed Malone|cfz@eclipse.co.uk|02/09/06 at 08:27:18|obadiah|xx|0|86.131.87.233|Tyrannosaurs get a father figure

Fossil hunters find the first Jurassic specimen of this fearsome family.

Michael Hopkin
8 February 2006

Ask any dinner-party palaeontologist and they'll tell you that, despite its star turn in Jurassic Park, Tyrannosaurus rex didn't live in the Jurassic period. But now a team in China has found a tyrannousaur that did, and it gives us valuable clues about the rise of this clan of prehistoric predators.

The new species, found in Xinjiang province in northwestern China, lived around 160 million years ago. This makes it more than twice as old as T. rex, and the most primitive known member of the family.

At just 3 metres long, the creature is a small relative of T. rex, which could reach a mighty 13 metres. But its gaping, beak-like face armed with teeth, and its powerful legs, show that it too would have been a ferocious killer.

The dinosaur's discoverers, led by Xing Xu of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, have named it Guanlong wucaii - meaning 'crested dragon from the five colours'. The name comes from the huge nasal crest on the creature's head, and the fact that it was found in a region of China characterized by many-coloured rocks. The team describes the find in this week's Nature 1.

Rare vintage

Dinosaur specimens of this vintage are rare, says Mark Norell, who is based at the American Museum of Natural History in New York and is part of the team who studied the find. Most other Jurassic dinosaur fossils have been unearthed in the Americas. "This fills in a big blank about tyrannosaurs," he says. "With samples from only one continent, you don't have a good picture."

The presence of a nasal crest is particularly interesting, says Norell, because it is so similar to the head ornaments carried by many of today's birds. Both birds and carnivorous dinosaurs such as tyrannosaurs belong to the evolutionary family known as the theropods.

The crest of G. wucaii probably functioned as a signal, either to attract potential mates or for species recognition. "It would not have been used for fighting - it would have been paper-thin," Norell says.

If it was a sexual ornament, it might imply that this individual was a male. But if it was for species recognition, that would leave the dinosaur's sex in the balance, and determining sex using bones alone is tricky. "That's still a long way ahead," says Norell.
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