34 (A) This is because all of the Utahraptors had been dead for fifty million years before the T-rex appeared. (B) With such a dangerous build, the T-rex was thought to have been the most terrifying of all carnivorous dinosaurs. (C) However, it would be premature to say for sure what it was that brought the dinosaurs to extinction. (D) With its sturdy back legs, the Utahraptor could probably outrun any other creature.