T-Rex's head was about 5 feet long. Its skull had holes in it which made it lighter and easier to carry around. T-Rex was one of the best known dinosaurs, but it didn't live all that long. T-Rex came along just before the dinosaurs became extinct. You often see T-Rex pictures with his tail stretched out behind him. He did this for balance. T-Rex had a very good sense of smell. When T-Rex ran, he could go 20 miles per hour and could cover 15 feet in one step!
Like other tyrannosaurids, Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to its large and powerful hind limbs, Tyrannosaurus fore limbs were short but unusually powerful for their size and had two clawed digits. The most complete specimen measures up to 12.3 m (40 ft) in length, up to 4 meters (13 ft) tall at the hips, and up to 6.8 metric tons (7.5 short tons) in weight. Although other theropods rivaled or exceeded Tyrannosaurus rex in size, it is still among the largest known land predators and is estimated to have exerted the largest bite force among all terrestrial animals. By far the largest carnivore in its environment, Tyrannosaurus rex was most likely an apex predator, preying upon hadrosaurs, ceratopsians, and possibly sauropods. Some experts, however, have suggested the dinosaur was primarily a scavenger. The question of whether Tyrannosaurus was an apex predator or a pure scavenger was among the longest ongoing debates in paleontology. It is accepted now that Tyrannosaurus rex acted as a predator, and scavenged as modern mammalian and avian predators do.