Why Is T-rex Called the King of the Dinosaurs? Tyrannosaurus rex often called T. rex or colloquially T-rex, is one of the most well-represented of the large theropods and is a large, carnivorous dinosaur that walked on two legs.
The name Tyrannosaurus rex means “king of the tyrant lizards”: “tyranno” means tyrant in Greek; “saurus” means lizard in Greek, and “rex” means “king” in Latin. In 1905, Henry Fairfield Osborn, president of the American Museum of Natural History at the time, named Tyrannosaurus rex.
The species Tyrannosaurus rex, commonly abbreviated to T. rex, is one of the dinosaurs most often featured in popular culture around the world. It lived in what is now western North America. Some scientists consider Tarbosaurus bataar from Asia to represent a second species of Tyrannosaurus, while others maintain Tarbosaurus as a separate genus. Several other genera of North American tyrannosaurids have also been synonymized with Tyrannosaurus.
Like other tyrannosaurids, Tyrannosaurus was a bipedal carnivore with a massive skull balanced by a long, heavy tail. Relative to the large and powerful hindlimbs, Tyrannosaurus forelimbs were small, though unusually powerful for their size. While Tyrannosaurus was long thought to have only two digits on each hand, the discovery of a complete T. rex forelimb in 2007 showed that it in fact had three fingers, though the third was vestigial.
Although other theropods rivaled or exceeded T. rex in size, it was the largest known tyrannosaurid and one of the largest known land predators, measuring nearly 13 metres (43 feet) in length and up to 6.8 metric tons (7.5 short tons) in weight.
Fossils of T. rex have been found in North American rock formations dating to the last three million years of the Cretaceous Period at the end of the Maastrichtian stage, approximately 68.5 to 65.5 million years ago; it was among the last dinosaurs to exist prior to the Cretaceous–Tertiary extinction event. More than 30 specimens of T. rex have been identified, some of which are nearly complete skeletons.
Some researchers have discovered soft tissue as well. The abundance of fossil material has allowed significant research into many aspects of its biology, including life history and biomechanics. The feeding habits, physiology and potential speed of T. rex are often subjects of debate.
Content for this question contributed by Ian Winn, resident of Pacific Palisades, Los Angeles, California, USA
