Father of Tyrannosaurus is unearthed in China

China Travel Services

An artist's conception of Guanlong wucaii, the earliest known tyrannosaur.
Zhongda Zhang-IVPP

By Dan Vergano, USA TODAY
The King of Dinosaurs had humble beginnings, but he still wore a crown, say paleontologists who have unearthed a smaller, crested-skull predecessor to Tyrannosaurus rex in western China.

The dinosaur, called Guanlong wucaii, was 10 feet long, less than a third the length of its famous descendant. It lived 160 million years ago and is the oldest-known member of the tyrannosaur family, says the team led by Xing Xu of China's Institute of Vertebrate Paleontology and Paleoanthropology.

T. rex lived about 85 to 65 million years ago. Until now, researchers had only uncovered predecessors dating to 110 million years ago.

Guanlong wucaii means crowned dragon from Wucaii, a brightly colored, rocky region in China's Xinjiang Province. "It doesn't really shout out tyrannosaurus when you first see it," says team member James Clark of George Washington University. "That's because it is really a primitive tyrannosaur."

Most striking, the team reports in Thursday's Nature journal, is that Guanlong sported a large crest atop its skull. Scientists suggest it was a display feature, similar to a peacock's tail or antelope's horns, signaling maturity for mating or membership in the species.

Paleontologist Thomas Holtz of the University of Maryland in College Park says this discovery helps place tyrannosaurs in the historical timeline of carnivorous dinosaurs. The find suggests that tyrannosaurs started out in the middle of the food chain, as "secondary" predators who lived in fear of the larger Allosaurus, the carnivore giants of the Jurassic era.

"The crest is just very surprising," says Holtz, who was not a member of the discovery team.

All discovered tyrannosauroids have some ornamentation along their nasal bones, from small horns to roughened textures, but the tall, narrow crest of Guanlong was unexpected, Holtz says.

Guanlong had long, useful forearms and three-fingered hands that were "probably used a great deal in handling prey," says team member Mark Norell of the American Museum of Natural History in New York. In contrast, T. rex had heavy, bone-crushing teeth, a thick skull, seemingly useless, puny forearms and two-fingered claws.

Despite the differences, Guanlong undoubtedly belongs to the tyrannosaur family, Holtz says. The teeth, nasal bones and pelvis of the creature, for example, place it squarely in their midst. But he says Guanlong likely was on an outer branch of the family tree, not a direct ancestor of T. rex.

The scientists discovered two Guanlong fossils buried atop one another in 2002. They removed the pair encased in rock to Beijing for further study. The team thinks the larger one, a 12-year-old, trampled the other, a 6-year-old, breaking its neck.

A scientific analysis of the fossilised remains has revealed the creature lived some 160 million years ago, about 90 million years before T. rex, and had an ornamental bony crest on its nose.

Scientists believe that the dinosaur belongs to the same group of extinct animals that gave rise to T. rex. Like other tyrannosaurs, it was a carnivore that walked on two legs, although it was substantially smaller than its more famous cousin.

A study by Chinese and American scientists, published today in the journal Nature, described the anatomy of the new dinosaur, which they have named Guanlong wucaii, or "crowned dragon of the five-coloured rocks".

The scientists, led by Xing Xu of the Institute of Vertebrate Palaeontology and Palaeoanthropology in Beijing, found two relatively complete fossilised skeletons of the dinosaur in the coloured layers of rock that form the "badlands" of Xinjiang province in the far western region of China. Adult Guanlongs grew to a length of about 10ft, which probably meant that the dinosaur was a "secondary predator" to a larger species of meat-eater called Monolophosaurus which lived in the region at the same time.

"This is the best look so far at the ancestral condition from which the tyrant dinosaurs, T. rex and company, evolved," said Thomas Holtz, a specialist at the University of Maryland.

"The new 'crowned dragon' of Xinjiang is simply the latest discovery on the trail leading back to the origin of the tyrant kings," Dr Holtz said.

The unusual nasal crest does not appear to perform any practical function other than as an ornament for courtship displays, similar to the tail of the peacock or the antlers of an elk, the scientists said in Nature.

"Guanlong's cranial ornament may be a sexually selected trait, which has also been a suggested explanation for similar structures in some other non-avian dinosaur groups," the scientists said.

Dr Holtz said the nasal crest is the most spectacular feature of Guanlong, especially impressive because of its tall, narrow projection of bone with numerous hollow excavations.

"The fragile nature of these structures suggests that they served for visual signalling, so for species recognition and mating displays, rather than as weapons," Dr Holtz said.

Guanlong stood about 3ft tall at the hip and had relatively long, three-fingered arms rather than the stubby two-fingered forelimbs of T. rex. The scientists suspect it also had feathers, as did related dinosaurs of the time. T. rex, by comparison, stood more than 20ft tall and was at least 40ft long.

By studying its detailed anatomy, scientists hope that Guanlong will help them to understand how these large predatory creatures evolved over the course of more than 100 million years.

Guanlong Wucaii: The earliest known tyrannosaur
Fossils of the earliest known relative of Tyrannosaurus rex - one of the largest of the meat-eating dinosaurs - have been unearthed in the desert "badlands" of western China.

A scientific analysis of the fossilised remains has revealed the creature lived some 160 million years ago, about 90 million years before T. rex, and had an ornamental bony crest on its nose.

Scientists believe that the dinosaur belongs to the same group of extinct animals that gave rise to T. rex. Like other tyrannosaurs, it was a carnivore that walked on two legs, although it was substantially smaller than its more famous cousin.

A study by Chinese and American scientists, published today in the journal Nature, described the anatomy of the new dinosaur, which they have named Guanlong wucaii, or "crowned dragon of the five-coloured rocks".

The scientists, led by Xing Xu of the Institute of Vertebrate Palaeontology and Palaeoanthropology in Beijing, found two relatively complete fossilised skeletons of the dinosaur in the coloured layers of rock that form the "badlands" of Xinjiang province in the far western region of China. Adult Guanlongs grew to a length of about 10ft, which probably meant that the dinosaur was a "secondary predator" to a larger species of meat-eater called Monolophosaurus which lived in the region at the same time.
"This is the best look so far at the ancestral condition from which the tyrant dinosaurs, T. rex and company, evolved," said Thomas Holtz, a specialist at the University of Maryland.

"The new 'crowned dragon' of Xinjiang is simply the latest discovery on the trail leading back to the origin of the tyrant kings," Dr Holtz said.

The unusual nasal crest does not appear to perform any practical function other than as an ornament for courtship displays, similar to the tail of the peacock or the antlers of an elk, the scientists said in Nature.

"Guanlong's cranial ornament may be a sexually selected trait, which has also been a suggested explanation for similar structures in some other non-avian dinosaur groups," the scientists said.

Dr Holtz said the nasal crest is the most spectacular feature of Guanlong, especially impressive because of its tall, narrow projection of bone with numerous hollow excavations.

"The fragile nature of these structures suggests that they served for visual signalling, so for species recognition and mating displays, rather than as weapons," Dr Holtz said.

Guanlong stood about 3ft tall at the hip and had relatively long, three-fingered arms rather than the stubby two-fingered forelimbs of T. rex. The scientists suspect it also had feathers, as did related dinosaurs of the time. T. rex, by comparison, stood more than 20ft tall and was at least 40ft long.

By studying its detailed anatomy, scientists hope that Guanlong will help them to understand how these large predatory creatures evolved over the course of more than 100 million years.

The creatures lived in a vast, warm marsh subject to volcanic eruptions. The region today is best known for the desert settings in the 2000 movie Crouching Tiger, Hidden Dragon, says Clark.