The new dinosaur shows that even Tyrannosaurus rex had a modest beginning.
Named Moros intrepidus, or "predestined predator," a new species is one of the smallest Tyrannosaurs yet discovered from the Cretaceous period. The anal scales of the animal's legs indicate that the creature would stand only 1.2 meters in the hips and weighed about 78 kilos – the size of a deer mule, the researchers report on February 21 in . 19659002] Beginning about 96 million years ago, fossil is the oldest tyrannosaur found in North America. His discovery helps to fill the 70-year gap in the evolution of tyrannosaurs, which leads to ferocious giants like T. Teeth from the early, small tyrannosaurs were found in rocks in North America, belonging to the late Jurassic period about 1
Paleontologist Lindsey Zanno of the University of North Carolina at Raleigh and her colleagues have been digging for around 10 years in the state of Utah, Emery County, looking for hints to resolve this mystery. That's where the team discovered M. intrepidus a long, thin leg, a characteristic feature of the fast runner, in contrast to later titanic tyrannosaurs.
What shows Moros that the ancestors of the great tyrannosaurs were small and fast. – says Thomas Carr, a paleontologist of the vertebrates at the Carthage College in Chenosh, Wisconsin, who was not involved in the study. And this "suggests that the Tyrannosaurs have become a giant for some time in the 16 millionth stretching between Moros and the oldest of the great guys"
Comparison M. fossils with other Tyrannosaurs, To see where it fits into the tribal tree of the Tyrannosaurus, researchers have determined that M. intrepidus came from Asia. It was part of a large migration that included mammals, lizards and dinosaurs moving between modern Siberia and Alaska during casual sea level falls, according to authors of the Cretaceous period. but not a tyrannosaurus. "They grow rapidly in size and go really fast to become the dominant predators of post-ecosystems," she says.
Even with the discovery M. intrepidus the picture of the evolution of the Tyrannosaurus remains incomplete. "It's great that [the new fossil] helps fill a part of the story," says paleontologist vertebrates and a Tyrannosaurist Thomas Holts Jr. at the University of Maryland in college. But scientists need to find the rest of the skeleton M. intrepidus as well as other tyrannosaurs in the narrow 16 millionth period between M. intrepidus and his giant descendants to help determine when the creatures grew in size. "The story of the tyrannosaurs, of course, is not over," he says.