Giant dinosaur that predates Tyrannosaurus rex unveiled in Utah

Paleontologists on Wednesday unveiled a new dinosaur discovered four years ago in southern Utah that proves giant tyrant dinosaurs like the Tyrannosaurus rex existed 10 million years earlier than previously believed.

A full skeletal replica of the carnivore — the equivalent of the great uncle of the T. rex — was on display at the Natural History Museum of Utah alongside a 3-D model of the head and a large painted mural of the dinosaur roaming a shoreline.

It was the public's first glimpse at the new species, which researchers named Lythronax argestes. The first part of the name means "king of gore," and the second part is derived from poet Homer's southwest wind.

The fossils were found in the Grand Staircase-Escalante National Monument in November 2009, and a team of paleontologists spent the past four years digging them up and traveling the world to confirm they were a new species.

Paleontologists believe the dinosaur lived 80 million years ago in the late Cretaceous Period on a landmass in the flooded central region of North America.

The discovery offers valuable new insight into the evolution of the ferocious tyrannosaurs that have been made famous in movies and captured the awe of schoolchildren and adults alike, said Thomas Holtz Jr., a vertebrate paleontologist at the University of Maryland department of geology.

"This shows that these big, banana-tooth bruisers go back to the very first days of the giant tyrant dinosaurs," said Holtz, who reviewed the findings. "This one is the first example of these kind of dinosaurs being the ruler of the land."

The new dinosaur likely was a bit smaller than the Tyrannosaurus rex but was otherwise similar, said Mark Loewen, a University of Utah paleontologist who co-authored a journal article about the discovery with fellow University of Utah paleontologist Randall Irmis.

It was 24 feet long and 8 feet tall at the hip, and was covered in scales and feathers, Loewen said. Asked what the carnivorous dinosaur ate, Loewen responded: "Whatever it wants."

"That skull is designed for grabbing something, shaking it to death and tearing it apart," he said.

The fossils were found by a seasonal paleontologist technician for the Bureau of Land Management who climbed up two cliffs and stopped at the base of a third in the national monument.

"I realized I was standing with bone all around me," said Scott Richardson, who called his boss, Alan Titus, to let him know about the fossils.

Loewen and others spent three years traveling the world to compare the fossils to other dinosaurs to be absolutely sure it was a new species. The findings are being published in the journal PLOS One.

The fossils were found in a southern Utah rock formation that also has produced the oldest-known triceratops, named "Diabloceratops," and other dome-headed and armored dinosaurs.

There are about 1 million acres of cretaceous rocks that could be holding other new species of dinosaurs, said Titus, the BLM paleontologist who oversees the Grand Staircase-Escalante National Monument. Only about 10 percent of the rock formation has been scoured, he said. Twelve other new dinosaurs found there are waiting to be named.

"We are just getting started," Titus said. "We have a really big sandbox to play in."

Holtz said the finding is a testament to the bounty of fossils lying in the earth in North America. He predicts more discoveries in Utah.

"It shows we don't have to go to Egypt or Mongolia or China to find new dinosaurs," Holtz said. "It's just a matter of getting the field teams out."

The Associated Press