Any of a genus (Tyrannosaurus) of huge, bipedal, flesh-eating theropod dinosaurs of the Upper Cretaceous Period in North America and Asia, esp. the largest species (Tyrannosaurus rex)
Any of various very large carnivorous dinosaurs of the genus Tyrannosaurus and related genera of the Cretaceous Period. Tyrannosaurs had very small forelimbs and a large head with sharp teeth. They walked on two legs, probably bent forward with their long tail stretched out as a counterbalance. Tyrannosaurs were theropods and probably distantly related to birds. The largest species, T. rex, grew to lengths of 14.3 m (47 ft) or more and may have been the largest land predator that ever lived.