Montanoceratops /mɒnˌtænoʊˈsɛrətɒps/ is an extinct genus of small ceratopsian dinosaur that lived approximately 70 million years ago during the latter part of the Cretaceous Period in what is now Montana and Alberta. Montanoceratops was a small sized, moderately-built, ground-dwelling, quadrupedal herbivore, that could grow up to an estimated 3 m (9.8 ft) long. The ceratopsians were a group of dinosaurs with parrot-like beaks which fed on vegetation and thrived in North America and Asia during the Cretaceous Period, which ended approximately 66 million years ago, at which point they all became extinct.
Montanoceratops was a typical primitive ceratopsian in many respects, distinguished from the later species by the presence of claws, rather than hooves, and by having teeth in its upper jaw, rather than a toothless beak. It was once thought to have a horn on its nose but that was a misplaced cheek horn. Another unusual feature was the presence of tall spines on the bones of the tail. Although these would not have been visible during life, they would have made the tail unusually deep in cross-section. Since the tail was also highly flexible, it is possible that it was used in intra-species signalling, and that the deep shape made it more visible. Montanoceratops, like all Ceratopsians, was a herbivore. It would have used its sharp Ceratopsian beak to bite off the leaves or needles.
In specimen AMNH 5464, the neural spines of several of the caudal vertebrae show an ankylosis that is a result of a severe injury sustained by this individual during its lifetime. Evidence of this injury is also present in the outer surface of the left ischium, where there is a large, irregularly shaped growth of bone that has formed across a healed fracture.