Tyrannosaurus rex dinosaurs hunting on a dry riverbed, artwork. This large bipedal dinosaur is one of the largest ever terrestrial predators. From its large olfactory lobes, it is thought to have possessed a very well developed sense of smell. To find the amount of food it needed to sustain itself, it probably relied on a combination of hunting and scavenging. Its fossils are found in North America, and date to the Cretaceous. This view is intended to depict what a mammal would have seen from ground level. A small conifer cone similar to those of the Sequoiadendron, is in the bottom left foreground.