Ornithischia is an extinct clade of mainly herbivorous dinosaurs characterized by a pelvic structure superficially similar to that of birds. The name Ornithischia, or "bird-hipped", reflects this similarity and is derived from the Greek stem ornith- (ὀρνιθ-), meaning "bird", and ischion (ἴσχιον), meaning "hip". However, birds are only distantly related to this group, as birds are theropod dinosaurs.
Protoceratops is a genus of small protoceratopsid dinosaurs that lived in Asia during the Late Cretaceous, around 75 to 71 million years ago. The genus Protoceratops includes two species: P. andrewsi and the larger P. hellenikorhinus. The former was described in 1923 with fossils from the Mongolian Djadokhta Formation, and the latter in 2001 with fossils from the Chinese Bayan Mandahu Formation. Protoceratops was initially believed to be an ancestor of ankylosaurians and larger ceratopsians, such as Triceratops and relatives, until the discoveries of other protoceratopsids. Populations of P. andrewsi may have evolved into Bagaceratops through anagenesis.
Ceratopsia or Ceratopia is a group of herbivorous, beaked dinosaurs that thrived in what are now North America, Asia and Europe, during the Cretaceous Period, although ancestral forms lived earlier, in the Late Jurassic of Asia. The earliest known ceratopsian, Yinlong downsi, lived between 161.2 and 155.7 million years ago. The last ceratopsian species, Triceratops prorsus, became extinct during the Cretaceous–Paleogene extinction event, 66 million years ago.
Claosaurus is a genus of hadrosauroid dinosaur that lived during the Late Cretaceous Period (Santonian-Campanian).
Thescelosaurus is a genus of ornithischian dinosaur that lived during the Late Cretaceous period in western North America. It was named and described in 1913 by the paleontologist Charles W. Gilmore; the type species is T. neglectus. Two other species, T. garbanii and T. assiniboiensis, were named in 1976 and 2011, respectively. Additional species have been suggested but are currently not accepted. Thescelosaurus is the eponymous member of its family, the Thescelosauridae. Thescelosaurids are either considered to be basal ("primitive") ornithopods, or are placed outside of this group within the broader group Neornithischia.
Protoceratopsidae is a family of basal (primitive) ceratopsians from the Late Cretaceous period. Although ceratopsians have been found all over the world, protoceratopsids are only definitively known from Cretaceous strata in Asia, with most specimens found in China and Mongolia. As ceratopsians, protoceratopsids were herbivorous, with constantly replacing tooth batteries made for slicing through plants and a hooked beak for grabbing them. Protoceratopsids were small ceratopsians around 1-2.5 m in length. Their bony frill and horns were much smaller than more derived members of Ceratopsia, such as ceratopsids.
Arrhinoceratops is a genus of herbivorous ceratopsian dinosaur. The name was coined as its original describer concluded it was special because the nose-horn was not a separate bone, however further analysis revealed this was based on a misunderstanding. It lived during the latest Campanian/earliest Maastrichtian stage of the Late Cretaceous, predating its famous relative Triceratops by a few million years, although it was contemporary with Anchiceratops. Its remains have been found in Canada.
Heterodontosaurus is a genus of heterodontosaurid dinosaur that lived during the Early Jurassic, 200–190 million years ago. Its only known member species, Heterodontosaurus tucki, was named in 1962 based on a skull discovered in South Africa. The genus name means "different toothed lizard", in reference to its unusual, heterodont dentition; the specific name honours G. C. Tuck, who supported the discoverers. Further specimens have since been found, including an almost complete skeleton in 1966.
Hungarosaurus tormai, is a herbivorous nodosaurid ankylosaur from the Upper Cretaceous (Santonian) Csehbánya Formation of the Bakony Mountains of western Hungary. It is the most completely known ankylosaur from the Cretaceous of Europe.
Breviceratops is a genus of protoceratopsid dinosaur that lived during the Late Cretaceous in what is now the Barun Goyot Formation, Mongolia.
Zalmoxes is a genus of rhabdodontid ornithopod dinosaur from the Maastrichtian age of the Late Cretaceous in what is now Romania. The genus is known from specimens first named as the species Mochlodon robustum in 1899 by Franz Nopcsa before being reclassified as Rhabdodon robustum by him in 1915. In 1990, this name was corrected to Rhabdodon robustus by George Olshevsky and, in 2003, the species was once more reclassified as the type species Zalmoxes robustus. Zalmoxes refers to the Dacian deity Zalmoxis and robustus refers to the robustness of the remains. Also in 2003, another species was named, Zalmoxes shqiperorum, named for the Albanian name for Albanians.
Silvisaurus, from the Latin silva "woodland" and Greek sauros "lizard", is a nodosaurid ankylosaur from the Early to Late Cretaceous period. It is one of the only known dinosaur species named from Kansas and was designated the official state land fossil in 2023.
Jeholosaurus is a genus of neornithischian dinosaur from the Early Cretaceous Period. It is thought to have been a herbivorous small ornithopod.
Erlikosaurus is a genus of therizinosaurid that lived in Asia during the Late Cretaceous period. The fossils, a skull and some post-cranial fragments, were found in the Bayan Shireh Formation of Mongolia in 1972, dating to around 96 million and 89 million years ago. These remains were later described by Altangerel Perle and Rinchen Barsbold in 1980, naming the new genus and species Erlikosaurus andrewsi. It represents the second therizinosaur taxon from this formation with the most complete skull among members of this peculiar family of dinosaurs.
Heterodontosauridae is a family of ornithischian dinosaurs that were likely among the most basal (primitive) members of the group. Their phylogenetic placement is uncertain but they are most commonly found to be primitive, outside of the group Genasauria. Although their fossils are relatively rare and their group small in numbers, they have been found on all continents except Australia and Antarctica, with a range spanning the Early Jurassic to the Early Cretaceous.
Bakonydraco is a genus of pterodactyloid pterosaur from the Late Cretaceous period of what is now the Csehbánya Formation of the Bakony Mountains, Iharkút, Veszprém, western Hungary.
Albalophosaurus is a genus of marginocephalian ornithischian dinosaur that lived in Japan during the Early Cretaceous. The type species is Albalophosaurus yamaguchiorum.
The Csehbánya Formation is a geological formation in the Transdanubian Mountains of Veszprém County, Hungary. The formation dates to the Late Santonian of the Late Cretaceous. It represents a floodplain environment as opposed to the swampy lacustrine environment of the simultaneous Ajka Coal Formation, though there is complete overlap in terms of fauna. It underlies the Jákó Marl Formation, and laterally transitions to the Ajka Coal Formation.
This timeline of ceratopsian research is a chronological listing of events in the history of paleontology focused on the ceratopsians, a group of herbivorous marginocephalian dinosaurs that evolved parrot-like beaks, bony frills, and, later, spectacular horns. The first scientifically documented ceratopsian fossils were described by Edward Drinker Cope starting in the 1870s; however, the remains were poorly preserved and their true nature was not recognized. Over the next several decades, Cope named several such genera and species. Cope's hated rival, Othniel Charles Marsh, also described ceratopsian remains. In 1887, Marsh mistook a Triceratops horn for one belonging to a new species of prehistoric Bison. Marsh also named the eponymous genus Ceratops in 1888. The next year, he named the most famous ceratopsian, Triceratops horridus. It was the discovery of Triceratops that illuminated the ceratopsian body plan, and he formally named the Ceratopsia in 1890.
Mosaiceratops is a genus of ceratopsian, described by Zheng, Jin & Xu in 2015 and found in the Xiaguan Formation of Neixiang County. Mosaiceratops lived in the upper Cretaceous in what is now the Henan Province of China.
