New Dinosaur Species the 'King of Gore' a T. Rex Ancestor

Tyranosaurus rex -- Latin for "tyrant lizard king" -- was preceded by an ancestor with an even more menacing name: the King of Gore.

The recently discovered tyrannosaur species was announced Wednesday at the Natural History Museum of Utah in tandem with the publication of a scientific paper in the journal PLOS One.

Lythronax argestes, as the new dinosaur is officially known, was discovered by Scott Richardson of the Bureau of Land Management at the Grand Staircase-Escalante National Monument in southern Utah. Lythronax means "king of gore" and the second part of the name, argestes, refers to the American southwest. (The Latin name literally translates as "Gore King from the Southwest.")

The King of Gore roamed Western North America about 80 million years ago during the Late Cretaceous period, at least 10 million years earlier than T. rex. The discovery of Lythronax further solidifies evidence that the tyrannosaurs appeared earlier in dinosaur history than previously believed.

At the time, North America was split into two landmasses by a vast, but shallow, seaway. To the west, an island continent known as Laramidia stretched from modern-day Alaska to Mexico. The seaway eventually shrank, split across the Dakotas and retreated toward larger bodies of water, allowing the formation of contiguous North America.

"[Laramidia] hosted a vast array of unique dinosaur species and served as the crucible of evolution for iconic dinosaur groups such as the horned and duck billed dinosaurs," the University of Utah said in a statement about the new discovery. "This study also indicates that tyrannosaurid dinosaurs (the group of tyrannosaurs that includes T. rex) likely evolved in isolation on this island continent. Lythronax stands out from its contemporaries in having a much wider skull at the eyes and a narrow short snout, similar to its relative T. rex, which lived 10-12 million years later."

Despite its seniority, and a host of similarities including the same short snout, front-facing eyes and iconic little arms, the King of Gore would have been dwarfed by the T. rex if they lived at the same time.

T. rex was about 40 feet long and up to 20 feet tall. The Lythronax, by comparison was a lot smaller, measuring about 24 feet long and weighing about 2.5 tons.

Even though it was smaller, the King of Gore was still worthy of its name, well equipped to act as a top predator.

Mark Loewen, a research associate at the Natural History Museum of Utah and the study's lead author, said: "The width of the back of the skull of Lythronax allowed it to see with an overlapping field of view -- giving it the binocular vision -- very useful for a predator and a condition we associate with T. rex."

The geographic location of the Late Cretaceous dinosaurs in North America is also intriguing to paleontologists. Dinosaurs found in southern Laramidia -- which is now Utah, New Mexico, Texas and Mexico -- belong to the same groups but "differ at the species level" from their counterparts in northern Laramidia (Montana, the Dakotas and Canada).

"Lythronax may demonstrate that tyrannosaurs followed a pattern similar to what we see in other dinosaurs from this age, with different species living in the north and south at the same time," said study co-author Joseph Sertich.

But such a coexistence is puzzling, the researchers said, given that an enterprising dinosaur would have been able to walk from Alaska to Mexico if time permitted.

"Lythronax is a wonderful example of just how much more we have to learn about with world of dinosaurs," said Philip Currie, another of the study's co-author.