T-Rex or more formally known as Tyrannosaurus Rex (meaning “tyrant lizard king”, from the Greek tyrannos meaning “tyrant,” and sauros meaning “lizard” and the Latin rex meaning “king”) was a coelurosaurian theropod dinosaur.
T-Rex lived in the Cretaceous period about 67 to 65.5 million years ago in western North America. Fossils are found in a variety of rock formations. It was among the last non-avian dinosaurs to exist before the Cretaceous–Paleogene extinction event.
Theropod dinosaurs first appeared during the Carnian age of the late Triassic period about 230 million years ago. They became the only large terrestrial carnivores from the early Jurassic period until the close of the Cretaceous period, about 65 million years ago.
Tyrannosaurus ranged from Canada in the north down to at least New Mexico in the south.
In the Jurassic period, birds evolved from small specialized coelurosaurian theropod dinosaurs. Today, dinosaurs are represented by over 9,900 living species of birds.
Since it was first described in 1905, Tyrannosaurus Rex has become the most widely recognized dinosaur species in popular culture. It is the only dinosaur that is commonly known to the general public by its full scientific name and the scientific abbreviation T. Rex has also come into wide usage.