Tyrannosaurus, << tih `ran` uh SAWR uhs or ty `ran` uh SAWR uhs >> was a large, meat-eating dinosaur that lived about 68 million to 65 million years ago in what is now western North America. The name Tyrannosaurus means tyrant lizard. A tyrant is a cruel, powerful ruler. Tyrannosaurus got its name because scientists thought that such a huge beast must have ruled over all other animals, killing whatever and whenever it chose. The scientific name for this species is Tyrannosaurus rex.
Tyrannosaurus was one of the largest meat-eating dinosaurs. It was about 40 feet (12 meters) long, stood about 12 feet (3.7 meters) high at the hips, and weighed about 7 short tons (6.3 metric tons). Tyrannosaurus could rear up to a height of 18 feet (5.5 meters). However, the animal usually walked with its body parallel to the ground, holding its heavy, muscular tail out behind for balance.
Tyrannosaurus had a huge skull that grew as long as 41/2 feet (135 centimeters). The strong jaws had sharp teeth that were about 6 inches (15 centimeters) long. The animal’s short, flexible neck and powerful body allowed Tyrannosaurus to use its monstrous jaws to rip off large chunks of flesh. The dinosaur’s other deadly weapons were the sharp claws on its feet. Tyrannosaurus could hold an animal in its jaws and slash and tear at the body with its large claws.
Unlike the rest of the dinosaur’s body, its arms were tiny, and its hands had only two fingers tipped with little claws. Although the arms were small, they were strong. Tyrannosaurus may have used the arms to push itself up after it had been lying down.
Some scientists have suggested that the huge Tyrannosaurus would have moved too slowly to hunt live animals and instead fed on dead animals. But most scientists think Tyrannosaurus was an active hunter that could run for short distances. Tyrannosaurus may have waited in hiding for a plant-eating dinosaur, such as a hadrosaur, to get close. Tyrannosaurus could then make a quick rush and attack the animal with its sharp teeth and strong jaws.
