Deuterostomia Tyrannosaurus, meaning 'tyrant lizard' (from Greek tyrannos meaning 'tyrant,' and sauros meaning 'lizard') is a genus of coelurosaurian theropod dinosaur. The species Tyrannosaurus rex (rex meaning 'king' in Latin), commonly abbreviated to T.A_rex, is a fixture in popular culture. It lived throughout what is now western North America, at the time an island continent termed Laramidia, with a much wider range than other tyrannosaurids. Fossils are found in a variety of rock formations dating to the Maastrichtian age of the upper Cretaceous Period, 67 to 65.5 million years ago. It was among the last non-avian dinosaurs to exist before the Cretaceousa__Paleogene extinction event.
Contributions by Phlebas, Ancheta Wis, and 184.108.40.206.