Ceratopsians are herbivorous, beaked Ornithischian dinosaurs of the suborder Ceratopsia. They are a visually distinctive group of dinosaurs, sharing armored and often spiked heads, usually having elaborate bony head frills and often having long facial horns. These frills have been speculated to function as a defense mechanism, protecting their vulnerable necks. However they may have also been used in regulating body temperature or even as a form of visual display.
By far the most well known Ceratopsian in popular media is the Triceratops.