For ten points, name this dinosaur with three horns.
This dinosaur is divided into two species, Prorsus and Horridus, both of which were discovered by Marsh during the Bone Wars. This dinosaur, which lived during the Late Cretaceous, is more closely related to Chasmosaurus than to Centrosaurus, and its other relatives of this plant-eating, bird-hipped dinosaur include (*) Styracosaurus. Recent science suggests that this dinosaur may have just been the juvenile form of Torosaurus and that it developed holes in its frill as it aged. This dinosaur lived alongside Tyrannosaurus and may have defended itself by goring. For ten points, name this dinosaur with three horns.
This dinosaur is divided into two species, Prorsus and Horridus, both of which were discovered by Marsh during the Bone Wars.
{Triceratops}