Ceratopsia

Ceratopsians Temporal range: Late Jurassic – Late Cretaceous, 161–66 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Triceratops skeleton, American Museum of Natural History
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	†Ornithischia
Clade:	†Marginocephalia
Clade:	†Ceratopsia Marsh, 1890
Type species
†Ceratops montanus Marsh, 1888
Subgroups
†Albalophosaurus †Micropachycephalosaurus †Psittacosaurus †Chaoyangsauridae †Ajkaceratops? †Neoceratopsia Sereno, 1986 †Aquilops †Auroraceratops †Beg †Craspedodon? †Graciliceratops †Koreaceratops[1] †Kulceratops †Liaoceratops †Microceratus †Mosaiceratops †Notoceratops?[2] †Serendipaceratops?[2] †Archaeoceratopsidae †Archaeoceratops †?Helioceratops †?Yamaceratops †Euceratopsia Madzia et al., 2021 †Leptoceratopsidae †Coronosauria Sereno, 1986 †Protoceratopsidae †Ceratopsoidea Hay, 1902 sensu Sereno, 1998 †Ceratopsomorpha Wolfe & Kirkland, 1998 †Turanoceratops †Zuniceratops †Ceratopsidae

Ceratopsia or Ceratopia (/ˌsɛrəˈtɒpsiə/ or /ˌsɛrəˈtoʊpiə/; Greek: "horned faces") is a group of herbivorous, beaked dinosaurs that thrived in what are now North America, Europe, and Asia, during the Cretaceous Period, although ancestral forms lived earlier, in the Jurassic. The earliest known ceratopsian, Yinlong downsi, lived between 161.2 and 155.7 million years ago.^[3] The last ceratopsian species, Triceratops prorsus, became extinct during the Cretaceous–Paleogene extinction event, 66 million years ago.^[3]

Triceratops is by far the best-known ceratopsian to the general public. It is traditional for ceratopsian genus names to end in "-ceratops", although this is not always the case. One of the first named genera was Ceratops itself, which lent its name to the group, although it is considered a nomen dubium today as its fossil remains have no distinguishing characteristics that are not also found in other ceratopsians.^{[4][page needed]}