A new dinosaur shows that even Tyrannosaurus rex had a modest start. Moros intrepidus, or "the forerunner of doom", the new species is one of the smallest tyrannosaurs found since the Cretaceous period. Analyzes of the animal's pet's leg indicate that the creature should be only 1.2 meters in the thigh and weigh approximately 78 kilograms in the deer mule size, researchers reported on February 21 in . 19659002] An acquaintance about 96 million years ago, the fossil is the oldest tyrannosaur found in North America. His discovery helps to fill the 70 million-year gap in the evolution of tyrannosaurs leading to the fierce giants like T.
The teeth of the early, small tyrannosaurus are found in rocks in North America dating back to the late Jurassic period about 1
Paleontologist Lindsay Zano of North Carolina State University in Rally and her colleagues dug for about 10 years around Emery County in Utah, looking for clues to solve this mystery. That is why the team discovered M. long, slim leg of intrepidus characteristic of a quick runner, quite different from the later titanising tyrannosaurs. "What shows that the hereditary stock of the great tyrannosaurs is small and fast," says Thomas Carr, a backbone paleontologist at Carthage College in Kennesa, Vis who did not participate in the study. "suggests that Tyrannosaurs have become gigantic for some time in this 16-million-year period between Moros and the earliest of the great."
Comparison M. , to see where it fits into the tyrannosaurus tree, the researchers found that M. intrepidus originated in Asia, part of a large migration involving mammals, lizards and dinosaurs moving between modern Siberia and Alaska during occasional declines in sea level, the authors say.
But not Tyrannosaurs. "They quickly they grow in size and continue to be really fast to become predominant predators of late-natured ecosystems, "she says.
Even with the discovery of M. intrepidus the picture of the evolution of tyrannosaurus remains incomplete. "It's great that [the new fossil] helps to fill some of the story," says the paleontologist of vertebrate animals and the tyrannose expert Thomas Holz Jr. at the University of Maryland at College Park. But scientists have to find the rest of the skeleton of M. intrepidus as well as other tyrannosaurs in the narrow period of 16 million years between M. intrepidus and his giant descendants to help determine when creatures have increased. "The story of tyrannazar is definitely not over," he says.