A giant meat-eating dinosaur named “king of gore” due to its mouthful of large sharp teeth has been discovered by palaeontologists.
The 24 feet long carnivore, which weighed around 2.7 tons, roamed the earth more than 80 million years ago and is thought to be an early relative of the Tyrannosaurus rex.
The dinosaur, which has been named Lythronax argestes, is now the earliest example of these large tyrannosaurs that lived in North America during the late cretaceous period.
Experts previously believed T. rex and its relatives first emerged less than 70 million years ago, but the latest species lived around 10 million years earlier.
They say this suggests the Tyrannosaur family evolved while western North America became isolated as an island continent by sea level rise.
A reconstructed skull of Lythronax argestes (Mark Loewen, NHMU)
Dr Mark Loewen, research associate at the Natural History Museum of Utah and a lecturer at the University of Utah who led the research, 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.”
This skull shape is shared only by T. rex and its close cousin Tarbosaurus baatar. It was thought this type of wide skulled tyrannosaur only appeared 70 million years ago.
An artists reconstruction of how new tyrannosaur Lythronax argestes would have looked (Lukas Panzarin)
T. rex was one of the largest land predators that ever lived and at more than 40 feet long was almost twice the size of Lythronax.
The new fossil was discovered by workers from the Bureau for Land Management in a cliff face at the Grand-Staircase Escalante National Monument in Kane County, Utah.
The name Lythronax translates as king of gore while the second part of its name, argestes, refers to the location where it was found.
Palaeontologists believe the predator stalked the western shores of the island of Laramidia that now forms western North America.
At the time the continent was split by a large seaway that left the dinosaurs there to evolve in isolation.
Dr Loewen and his colleagues believe that Lythronax evolved during this period before later Tyrannosaurs were able to spread into Asia when sea levels dropped.
Dr Joseph Sertich, a co-author of the study, stated that, "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."
Lythronax lived alongside a range of horned dinosaurs and duck-billed hadrosaurs, which it probably hunted for food.
Dr Randall Irmis, who co-authored the study, which is published in the journal Public Library of Science One, said: “Lythronax and other tyrannosaurids diversified between 95-80 million years ago, during a time when North America's interior sea was at its widest extent.
“The incursion of the seaway onto large parts of low-lying Laramidia would have separated small areas of land from each other, allowing different species of dinosaurs to evolve in isolation on different parts of the land mass."
Lived: 70-95 million years ago
Length: 24 feet
Weight: 2.7 ton
Lived: 66-67 million years ago
Length: 40 feet
weight: 7.5 tons