Artwork of a triceratops dinosaur confronting a tyrannosaurus. These two dinosaurs coexisted in the late Cretaceous Period in what is now North America, and it is quite likely that tyrannosaurus fed on ceratopsians such as triceratops, as well as other dinosaurs from the hadrosaurid group. Triceratops was well armed, however, with a trio of sharp horns on its face, from which it gets its name.