The most complete specimen measures up to 12.3–12.4 m (40.4–40.7 ft) in length however, according to most modern estimates, T. Relative to its large and powerful hind limbs, the forelimbs of Tyrannosaurus were short but unusually powerful for their size, and they had two clawed digits. Like other tyrannosaurids, Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. It was the last known member of the tyrannosaurids and among the last non- avian dinosaurs to exist before the Cretaceous–Paleogene extinction event. Fossils are found in a variety of rock formations dating to the Maastrichtian age of the Upper Cretaceous period, 68 to 66 million years ago. Tyrannosaurus had a much wider range than other tyrannosaurids. It lived throughout what is now western North America, on what was then an island continent known as Laramidia. rex or colloquially T-Rex, is one of the best represented theropods. The species Tyrannosaurus rex ( rex meaning 'king' in Latin), often called T. Tyrannosaurus is a genus of large theropod dinosaur. (Gilmore, 1946) Bakker, Williams & Currie, 1988 (Gilmore, 1946) Charig in Appleby, Charig, Cox, Kermack & Tarlo, 1967
