For ten points, identify this dinosaur named for its three horns.
Discovered by John Hatcher and named by Othniel Charles Marsh, it was originally misidentified as a type of bison. The short bony frill behind its skull is thought to have regulated temperature and possibly provided defense against carnivores. Additionally, this herbivore is thought to have charged predators like a rhinoceros, with a pair of three-foot long horns above the eyes and a single horn above the nostrils. For ten points, identify this dinosaur named for its three horns.
Discovered by John Hatcher and named by Othniel Charles Marsh, it was originally misidentified as a type of bison.
{Triceratops}