While there is no agreement as to whether the Tarbosaurus bataar, along with its other tyrannosaurid relatives, were active predators or opportunistic scavengers, it is not disputed that they were the largest terrestrial carnivores ever to inhabit the Earth. These animals began to evolve during the start of the Early Jurassic period and by the Late Cretaceous tyrannosaurids were the dominant carnivores through the ancient world. Due to the lack of fossil evidence to show that the more ancient Tarbosaurus bataar ever existed outside of Asia, it is thought that tyrannosaurids developed first in Asia and then moved to North America over the Cretaceous land bridge.