0 a very large, meat-eating dinosaur with large, powerful back legs, small front legs and a long tail. T-Rex is short for Tyrannosaurus rex, a dinosaur of the tyrannosaurus genus (= a group of animals, less similar than a species):
The Giganotosaurus was a massive dinosaur that existed 30 million years before the T-rex.
Contrary to popular belief, the T rex is not the largest dinosaur in history.
