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.

Tyrannosaurus (Tyrannosaurus) is a genus under Tyrannosauridae. The only effective species is the model species Tyrannosaurus rex or Rexosaurus rex. It is a large carnivorous dinosaur with a length of about 15 meters, a hip height of about 5 meters, and a weight of about 8 metric tons to 13 tons. The Maastricht order, which lived at the end of the Cretaceous, was about 67 million to 66 million years ago. It was one of the last dinosaur populations before the Cretaceous-Tertiary extinction event. Fossils are distributed in the United States and western Canada in North America, and the distribution range is wider than that of other Tyrannosauridae. Western North America in the late Cretaceous period is an independent continent of Larramidia.

The Tyrannosaurus genus is a member of the Tyrannosauridae family, and the only valid species is the type species Tyrannosaurus rex, also known as the Rex dinosaur. It is a large carnivorous dinosaur with a length of about 15 meters, a hip height of about 5 meters, and a weight of about 8 to 13 tons. Tyrannosaurus lived in the Maastrichtian stage of the late Cretaceous period, approximately 67 to 66 million years ago, and was one of the last dinosaur populations before the Cretaceous Tertiary extinction event. Fossils are distributed in the western United States and Canada in North America, with a wider distribution range than other tyrannosaurids.