 The eye @-@ sockets of Tyrannosaurus are positioned so that the eyes would point forward , giving them binocular vision slightly better than that of modern hawks . Jack Horner also pointed out that the tyrannosaur lineage had a history of steadily improving binocular vision . It is hard to see how natural selection would have favored this long @-@ term trend if tyrannosaurs had been pure scavengers , which would not have needed the advanced depth perception that stereoscopic vision provides . In modern animals , binocular vision is found mainly in predators ( the principal exceptions are primates , which need it for leaping from branch to branch ) . Unlike Tyrannosaurus , Tarbosaurus had a narrower skull more typical of other tyrannosaurids in which the eyes faced primarily sideways . All of this suggests that Tarbosaurus relied more on its senses of smell and hearing than on its eyesight . In Gorgosaurus specimens , the eye socket was circular rather than oval or keyhole @-@ shaped as in other tyrannosaurid genera . In Daspletosaurus , this was a tall oval , somewhere in between the circular shape seen in Gorgosaurus and the ' keyhole ' shape of Tyrannosaurus . 
