Tyrannosaurus rex, also known as Rexosaurus rex, is the largest dinosaur in the Tyrannosauridae. It lived in the Maastricht period at the end of the Cretaceous, about 68.5 million to 65 million years ago, and was one of the last non-avian dinosaurs before the Cretaceous-Tertiary extinction event. The body length is about 11.5-14.7 meters, the average hip height is about 4 meters, the highest can reach 5.2 meters, and the head height is nearly 6 meters. The average weight is about 9 tons, and the maximum weight can reach 14.85 tons. The forelimbs were very short, with only two clawed fingers, while the hind limbs were strong and powerful, able to support their huge weight, feeding on other dinosaurs, and were the most powerful land predators of the time.