may be identical to Ceratops, which they considered a nomen dubium, or a growth stage of Albertaceratops. Species list The naming history can be summarised in a species list. Ceratops montanus Marsh 1888: nomen dubium; type species of Ceratops Marsh 1888; = Proceratops montanus (Marsh 1888) Lull 1906 Ceratops horridus Marsh 1889: = Triceratops horridus (Marsh 1889) Marsh 1889 Ceratops alticornis (Marsh 1887) Marsh 1889: nomen dubium; = Bison alticornis Marsh 1887, = Triceratops alticornis (Marsh 1887) Lull vide Hatcher, Marsh & Lull 1907 Ceratops paucidens (Marsh 1889) Marsh 1890: nomen dubium; = Hadrosaurus paucidens Marsh 1889; perhaps material of Lambeosaurus lambei Ceratops belli (Lambe 1902) Hatcher vide Stanton & Hatcher 1905: = Monoclonius belli Lambe 1902; = Chasmosaurus belli (Lambe 1902) Lambe 1914 Ceratops canadensis (Lambe 1902) Hatcher vide Stanton & Hatcher 1905: = Monoclonius canadensis Lambe 1902; = Eoceratops canadensis (Lambe 1902) Lambe 1915 Ceratops recurvicornis (Cope 1889) Hatcher vide Stanton & Hatcher 1905: = Monoclonius recurvicornis Cope 1889 Classification Ceratops was placed by Marsh in the Ceratopsidae in 1888. It thus belonged to the Ceratopsia, a group of herbivorous dinosaurs with parrot-like beaks which thrived in North America and Asia during the Late Cretaceous Period, which ended roughly 66 million years ago. In 1919 the group Ceratopsinae was named by Othenio Lothar Franz Anton Louis Abel, but this concept is problematic: Paul Sereno has defined it as equivalent to the Chasmosaurinae but other researchers limit it to Ceratops itself as its direct relationships are uncertain. Diet Ceratops, like all ceratopsians, was a herbivore biting off plant material with its beak and processing it with its tooth batteries. See also Timeline of ceratopsian research References External links https://web.archive.org/web/20090531083004/http://www.dinosaurvalley.com/Visiting_Drumheller/Kids_Zone/Groups_of_Dinosaurs/index.php Ceratopsids Late Cretaceous dinosaurs of North America Nomina dubia Fossil taxa described in 1888 Taxa named by Othniel Charles Marsh Paleontology in Montana Campanian genus first appearances Campanian genus extinctions Ornithischian genera