Daspletosaurus lived in a full world. There were einiosaurus, and styracosaurus. At that time, he had two claws and lived in the cretaceous just like tyrannosaurus rex, who came after daspletosaurus. They hunt meat, but plant eaters scavenged for plants for their meal. When they died, new dinosaurs took their place. After the Cretaceous was gone then then ice age appeared and all the other creatures and then we humans came along and then that's it.