Famous for being the sister species to Tyrannosaurus rex, Tarbosaurus bataar is often easily written off as being the Mongolian T-rex. The reality is that Tarbosaurus was quite different; besides being slightly smaller, it was also slimmer, with a narrower back portion of the skull, meaning it's vision was less directly binocular. This is due to the animals it hunted being different from those found in North America; whereas Tyrannosaurus went after hadrosaurs and ceratopsians, Tarbosaurus went after hadrosaurs and SAUROPODS, the latter apparently not needing as much binocular vision.