Researchers discovered a giant predatory dinosaur that kept the "small-bodied" tyrannosaurs from becoming the true king for millions of years.
The newly-discovered was named Siats meekerorum after a legendary Ute creature whose name meant "cannibalistic man-eating monster." The ferocious dinosaur was a member of the carcharodontosaur family, which holds some of the largest and most frightening species, and most likely walked the Earth 98-million years ago. The specimen was found in Utah, a North Carolina State University news release reported.
The only other carcharodontosaur found in North America was the Acrocanthosaurus, discovered in 1950, it was believed to have roamed the Earth 10 million years earlier than Siats meekerorum.
"It's been 63 years since a predator of this size has been named from North America," Lindsay Zanno, a North Carolina State University paleontologist with a joint appointment at the North Carolina Museum of Natural Sciences, said.. "You can't imagine how thrilled we were to see the bones of this behemoth poking out of the hillside."
The dinosaur is believed to have weighed about four tons and was 30 feet long; the large creature was not even full grown at the time of its death. Siats was one of the largest dinosaurs ever discovered, it is in competition with the Acrocanthosaurus for second place, and is topped by the Tyrannosaurus rex; which didn't hit the scene until 30 million years later.
Siats ravaged Utah during the Late Cretaceous period ("100 million years ago to 66 million years ago").
"Carcharodontosaurs reigned for much longer in North America than we expected," Zanno said.
Researchers have been working to determine who the top meat eater in North America during the Late Cretaceous, this discovery suggest Siats' power kept smaller Tyrannosaurs from reaching the top of the food chain.
"The huge size difference certainly suggests that tyrannosaurs were held in check by carcharodontosaurs, and only evolved into enormous apex predators after the carcharodontosaurs disappeared," Peter Makovicky, from Chicago's Field Museum of Natural History, said.
"Contemporary tyrannosaurs would have been no more than a nuisance to Siats, like jackals at a lion kill. It wasn't until carcharodontosaurs bowed out that the stage could be set for the evolution of T. rex," Zanno said.
During Siats' reign the region was lush with vegetation and teeming with prey and smaller predators.
"Stay tuned," Zanno said. "There are a lot more cool critters where Siats came from."
