Tyrannosaurus Rex was a very large theropod dinosaur. It was a carnivore (meat eater) and lived in North America and Asia right at the end of the Cretaceous period between 67 million and 65 million years ago. It was one of the last dinosaurs, and along with all other remaining dinosaurs, became extinct at the end of the Cretaceous period (the K-T boundary).

The first Tyrannosaurus Rex was found by noted fossil hunter, Barnum Brown, in Montana in 1902. The name "Tyrannosaurus Rex" means "Tyrant king lizard" (like most other dinosaurs Tyrannosaurus Rex's name derives from Ancient Greek), and was chosen by Henry Fairfield Osborn in 1905.

It is believed that an average Tyrannosaurus Rex was about 39 feet (nearly 12 meters) long, about 20 feet (more than 6 meters) tall, and probably weighed around 7 tons. The largest Tyrannosaurus Rex yet found, is nicknamed "Sue", and is in the Field Museum of Natural History in Chicago. Sue is 42 feet (nearly 13 meters) long. Although Tyrannosaurus is enormous, and was for many years believed to have been the largest carnivorous dinosaur - it now seems likely that there were some even large carnivores such as Gigantosaurus and Spinosaurus.

There is still some debate about Tyrannosaurus' lifestyle. Since the 1960s, many scientists have tended towards the view that Tyrannosaurus was probably mainly a scavenger, living off the carcasses of animals killed by other dinosaurs. Other scientists however think of it as an active predator, and point to the position of its eyes (which suggests binocular vision), and apparently large areas of the brain associated with sight and smell, as evidence in support of their position.

By S. Tanna. Discover more about Tyrannosaurus Rex at http://www.dinosaurjungle.com/dinosaur_species_tyrannosaurus_rex.php