Tyrannosaurus rex

Nov. 7 (Reuters): Scientists in Utah say they have discovered Tyrannosaurus rex’s “great-uncle”, a massive predator with a thick skull and large teeth dubbed the “king of gore”.

Bones of the 7.3-metre-long dinosaur, slightly smaller than T. rex and older by about 10 million years, were unveiled at the Natural History Museum of Utah in Salt Lake City yesterday, and an announcement of the species discovery was published in the scientific journal Plos One.

Scientists hope the find will help them better understand the ecosystem where the predator roamed.

Discovered by workers for the Federal Bureau of Land Management in eastern Utah in 2009, scientists named the animal Lythronax argestes, or “king of gore”, for its large teeth and apparent dominance as a predator.

“Discovering the Lythronax pushes back the evolution of the group that gives rise to T. rex, which is something we didn’t understand before,” said Mark Loewen, a geologist at the University of Utah, who led the dig for the new dinosaur. “Lythronax is like the great-uncle of T. rex.”

Paleontologists have thought that members of the group with characteristics like T. rex — large bodies, tiny arms, thick skulls and forward facing eyes — dated as far back as 70 million years, but the Lythronax shows signs of being at least 80 million years old.

Like its relative, the Lythronax is believed to have been the top predator of its time, roaming a stretch of land from Mexico to Alaska, including parts of Utah, during the Campanian stage of the Late Cretaceous period.

“The really cool thing is that this shows that the origins of the last known tyrannosaurs were in the southern part of North America as opposed to Asia or far North America,” as previously thought, said Andrew Farke, curator at the Raymond M. Alf Museum of Paleontology in Claremont, California.

Photos of the fossil remains of the newly discovered species were sent to Loewen and his team soon after they were discovered at the southern end of the Grand Staircase-Escalante National Monumentr.

The group spent the following two years retrieving, preserving and assembling the bones. Then, they travelled to locations where other bones from the tyrannosaur group were being studied.