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.