Tyrannosaurus rex was one of the largest theropod dinosaurs that ever existed. Its scientific name, Tyrannosaurus (tyrant lizard) rex (king) says it all. It lived in what is now western North America in the latest Cretaceous (68-66 million years ago). T. rex went extinct at the very end of the Cretaceous, and so is one of the last dinosaurs to have lived on earth. Scientific Name: Tyrannosaurus rex Characteristics: Tyrannosaurus rex was a large (at least 40 feet), massively built (5-6 metric tons), bipedal dinosaur. The head was huge as our Tyrannosaurus rex toy shows, and the jaws contained lots of sharp teeth, some at least six inches in length! Each tooth had serrations on both the front and back edges, working like a steak knife to easily cut through the flesh of its prey. Tyrannosaurus rex would have been able to take down and eat any dinosaur it wanted to. Size: This Tyrannosaurus Rex toy model is 8.75 inches long and 3.25 inches high. The Tyrannosaurus Rex is