Artwork of a male and female Tyrannosaurus rex, an apex predator of the Late Cretaceous period, living in the last 2 million years of that time (68-66 million years ago). T rex had the strongest bite of any known dinosaur, more than enough to puncture bone. Its arms, though small, were well muscled and it may have used them to grasp prey during a kill. Its main method of attack was an ambush. It would run at the prey with its mouth agape and inflict a crushing bite. There is no firm proof that it had feathers, but dinosaurs closely related to it, from which is descended, definitely did have primitive feathery integuments, so it's plausible that T rex had them too. In this image, a male (foreground) and female are depicted with differences due to sexual dimorphism.