Ceratopsia
Ceratopsians | |
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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 | |
|
Ceratopsia or Ceratopia (
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]
Description
Early members of the ceratopsian group, such as
Ceratopsians are easily recognized by features of the
The epoccipital is a distinctive
History of study
The first ceratopsian remains known to science were discovered during the U.S. Geological and Geographical Survey of the Territories led by the American
In 1888 and 1889,
Classification
Ceratopsia was coined by
Following Marsh, Ceratopsia has usually been classified as a suborder within the order Ornithischia. While ranked taxonomy has largely fallen out of favor among dinosaur paleontologists, some researchers have continued to employ such a classification, though sources have differed on what its rank should be. Most who still employ the use of ranks have retained its traditional ranking of suborder,[17] though some have reduced to the level of infraorder.[18]
Phylogeny
In
The
All previously published neoceratopsian phylogenetic analyses were incorporated into the analysis of Eric M. Morschhauser and colleagues in
Ceratopsia |
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Paleobiology
Unlike almost all other dinosaur groups, skulls are the most commonly preserved elements of ceratopsian skeletons and many species are known only from skulls. There is a great deal of variation between and even within ceratopsian species. Complete growth series from embryo to adult are known for Psittacosaurus and Protoceratops, allowing the study of ontogenetic variation in these species.[21][22]
Most restorations of ceratopsians show them with erect hindlimbs but semi-sprawling forelimbs, which suggest that they were not fast movers. But Paul and Christiansen (2000) argued that at least the later ceratopsians had upright forelimbs and the larger species may have been as fast as rhinos, which can run at up to 56 km or 35 miles per hour.[23]
A
Paleoecology
Paleobiogeography
Ceratopsia appears to have originated in Asia, as all of the earliest members are found there. Fragmentary remains, including teeth, which appear to be neoceratopsian, are found in North America from the Albian stage (112 to 100 million years ago), indicating that the group had dispersed across what is now the Bering Strait by the middle of the Cretaceous Period.[26] Almost all leptoceratopsids are North American, aside from Udanoceratops, which may represent a separate dispersal event, back into Asia. Ceratopsids and their immediate ancestors, such as Zuniceratops, were unknown outside of western North America, and were presumed endemic to that continent.[6][27] The traditional view that ceratopsoids originated in North America was called into question by the 2009 discovery of better specimens of the dubious Asian form Turanoceratops, which confirmed it as a ceratopsid. It is unknown whether this indicates ceratopsids actually originated in Asia, or if the Turanoceratops immigrated from North America.[28]
Possible ceratopsians from the Southern Hemisphere include the Australian Serendipaceratops, known from an ulna, and Notoceratops from Argentina is known from a single toothless jaw (which has been lost).[29] Craspedodon from the Late Cretaceous (Santonian) of Belgium may also be a ceratopsian, specifically a neoceratopsian closer to ceratopsoidea than protoceratopsidae.[30] Possible leptoceratopsid remains have also been described from the early Campanian of Sweden.[31]
Ecological role
Psittacosaurus and Protoceratops are the most common dinosaurs in the different Mongolian sediments where they are found.[6] Triceratops fossils are far and away the most common dinosaur remains found in the latest Cretaceous rocks in the western United States, making up as much as 5/6ths of the large dinosaur fauna in some areas.[32] These facts indicate that some ceratopsians were the dominant herbivores in their environments.
Some species of ceratopsians, especially Centrosaurus and its relatives, appear to have been gregarious, living in
References
- S2CID 23743082.
- ^ S2CID 128686247.
- ^ a b Holtz, Thomas R. Jr. (2011) Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages, Winter 2010 Appendix.
- ^ Dodson, P. 1996. The Horned Dinosaurs. Princeton: Princeton University Press. 346pp.
- ISBN 978-0-375-82419-7.
- ^ a b c You H. & Dodson, P. 2004. Basal Ceratopsia. In: Weishampel, D.B., Dodson, P., & Osmolska, H. (Eds.). The Dinosauria (2nd Edition). Berkeley: University of California Press. Pp. 478-493.
- ^ a b Dodson, P., Forster, C.A., & Sampson, S.D. 2004. Ceratopsidae. In: Dodson, P., Weishampel, D.B., & Osmolska, H. (Eds.). The Dinosauria (2nd Edition). Berkeley: University of California Press. Pp. 494-513.
- ^ ISBN 978-0-691-02882-8.
- ISBN 978-0-253-35701-4.
- ISBN 978-0-520-24209-8.
- ^ Marsh, Othniel C. (1889). "The skull of the gigantic Ceratopsidae". American Journal of Science. 3rd Series. 38: 501–506.
- ISBN 0-405-12713-8
- ISBN 978-1-55791-634-1
- ^ Cope, E.D. (1876). "Descriptions of some vertebrate remains from the Fort Union Beds of Montana". Proceedings of the Academy of Natural Sciences of Philadelphia. 28: 248–261.
- S2CID 130812960.
- ^ Steel, R. 1969. Ornithischia. In: Kuhn, O. (Ed.). Handbuch de Paleoherpetologie (Part 15). Stuttgart: Gustav Fischer Verlag. 87pp.
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- ^ Benton, M.J. (2004). Vertebrate Palaeontology, Third Edition. Blackwell Publishing, 472 pp.
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- ^ Dodson, P (1976). "Quantitative aspects of relative growth and sexual dimorphism in Protoceratops". Journal of Paleontology. 50: 929–940.
- S2CID 85280946.
- ISBN 0-253-35358-0.
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- ^ Chinnery, B.J.; Lipka, T.R.; Kirkland, J.I.; Parrish, J.M.; Brett-Surman, M.K. (1998). "Neoceratopsian teeth from the Lower to Middle Cretaceous of North America. In: Lucas, S.G., Kirkland, J.I., & Estep, J.W. (Eds.). Lower and Middle Cretaceous Terrestrial Ecosystems". New Mexico Museum of Natural History and Science Bulletin. 14: 297–302.
- S2CID 86541770.
- S2CID 21951969.
- ^ Rich, T.H. & Vickers-Rich, P. 2003. Protoceratopsian? ulnae from the Early Cretaceous of Australia. Records of the Queen Victoria Museum. No. 113.
- ^ Godefroit, Pascal; Lambert, Olivier (2007). "A re-appraisal of Craspedodon lonzeensis Dollo, 1883 from the Upper Cretaceous of Belgium: the first record of a neoceratopsian dinosaur in Europe?". Bulletin de l'Institut Royal des Sciences Naturelles de Belgique, Sciences de la Terre. 77: 83–93.
- S2CID 129733977.
- ISBN 0-14-010055-5
External links
- Dinosaurs portal
- Introduction to the Ceratopsians, University of California Museum of Paleontology
- Marginocephalia at Palaeos.com (technical)