Triceratops (/traɪˈsɛrətɒps/try-SERR-ə-tops; lit. ’three-horned face’) is a genus of chasmosaurineceratopsiandinosaur that lived during the late Maastrichtian age of the Late Cretaceousperiod, about 68 to 66 million years ago in what is now western North America. It was one of the last-known non-avian dinosaurs and became extinct in the Cretaceous–Paleogene extinction event 66 million years ago.
Bearing a large bony frill, three horns on the skull, and a large, four-legged body, exhibiting convergent evolution with bovines and rhinoceroses, Triceratops is one of the most recognizable of all dinosaurs and the most well-known ceratopsian. It was also one of the largest, up to 8–9 metres (26–30 ft) long and 5–9 metric tons (5.5–9.9 short tons) in body mass.
The functions of the frills and three distinctive facial horns on its head have long inspired countless debates. Traditionally, these have been viewed as defensive weapons against predators. More recent interpretations find it probable that these features were primarily used in species identification, courtship, and dominance display, much like the antlers and horns of modern ungulates.