Gorgosaurus, meaning fierce lizard, is a genus of tyrannosaurid theropod dinosaur that live in western North America during the late Cretaceous. Gorgosaurus was smaller than Tyrannosaurus with adults reaching 26-30 ft in length. Gorgosaurus lived in a lush floodplain environment along the edge of an inland sea at times sharing territory with other tyrannosaurids such as Daspletosaurus. As an apex predator it preyed upon ceratopsids and hadrosaurs.