Allotyrannus

Allotyrannus was a species of Tyrannosaurid that was indigenous to what is now North America. It was among the few Tyrannosaurids, along with Nanotyrannus, to survived the invasion of the invasive Tyrannosaurus. It was likely a social pack hunter. It was also the first ever species of Tyrannosaurid to be discovered not having feathers, so it has proven that not all large Tyrannosaurids have feathers. Allotyrannus fed on variety of large prey items like Triceratops and Hadrosaurs. It is possible that Allotyrannus went extinct with almost all other non-avian dinosaurs due to the effects of an asteroid impact in the Gulf of Mexico.