Tyrannosaurus

Tyrannosaurus is a genus of large theropod dinosaur. The type species Tyrannosaurus rex, often shortened to T. rex or colloquially T-Rex, is one of the best represented theropods. It lived throughout what is now western North America, on what was then an island continent known as Laramidia. Tyrannosaurus had a much wider range than other tyrannosaurids. Fossils are found in a variety of rock formations dating to the latest Campanian-Maastrichtian ages of the Late Cretaceous period, 72.7 to 66 million years ago. It was the last known member of the tyrannosaurids and among the last non-avian dinosaurs to exist before the Cretaceous–Paleogene extinction event.