List of ichthyosauromorph genera

This list of ichthyosauromorphs is a comprehensive listing of all genera that have ever been included in the clade Ichthyosauromorpha, excluding purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considered invalid, doubtful (nomen dubium), or were not formally published (nomen nudum), as well as junior synonyms of more established names, and genera that are no longer considered ichthyopterygian. Non-ichthyosaur ichthyopterygians shall be noted as such. This list contains 108 genera.

Scope and terminology

There is no official, canonical list of ichthyosauromorph genera but one of the most thorough attempts can be found at the "Ichthyosauromorpha" section of Mikko Haaramo's Phylogeny Archive.

Naming conventions and terminology follow the International Code of Zoological Nomenclature. Technical terms used include:

• Junior synonym: A name which describes the same taxon as a previously published name. If two or more genera are formally designated and the type specimens are later assigned to the same genus, the first to be published (in chronological order) is the senior synonym, and all other instances are junior synonyms. Senior synonyms are generally used, except by special decision of the ICZN, but junior synonyms cannot be used again, even if deprecated. Junior synonymy is often subjective, unless the genera described were both based on the same type specimen.
• Nomen nudum (Latin for "naked name"): A name that has appeared in print but has not yet been formally published by the standards of the ICZN. Nomina nuda (the plural form) are invalid, and are therefore not italicized as a proper generic name would be. If the name is later formally published, that name is no longer a nomen nudum and will be italicized on this list. Often, the formally published name will differ from any nomina nuda that describe the same specimen. In this case, these nomina nuda will be deleted from this list in favor of the published name.
• Preoccupied name: A name that is formally published, but which has already been used for another taxon. This second use is invalid (as are all subsequent uses) and the name must be replaced. As preoccupied names are not valid generic names, they will also go unitalicized on this list.
• Nomen dubium (Latin for "dubious name"): A name describing a fossil with no unique diagnostic features. As this can be an extremely subjective and controversial designation, this term is not used on this list.

The list

Genus Authors Year Status Age Location Notes Acamptonectes Fischer et al. 2012 Valid eK to lK Europe Actiosaurus Sauvage 1883 Disputed Europe Acuetzpalin Barrientos et al. 2020 Valid lJ North America Aegirosaurus Bardet Fernández 2000 Valid lJ Europe A 2 meter long ophthalmosaurid whose remains were discovered in the Solnhofen limestone and mistaken for a new Ichthyosaurus species. In 2000 scientists concluded that the fossil material should be assigned to a new genus. Anhuisaurus Chen 1985 Jr. synonym N/A N/A Preoccupied by lizard genus Anhuisaurus Hou, 1974. Junior synonym of Chaohusaurus. Arthropterygius Maxwell 2010 Valid lJ North America Athabascasaurus Druckenmiller Maxwell 2010 Valid eK North America Auroroborealia Zvernikov et al. 2021 Valid lT Asia Barracudasauroides Maisch 2010 Valid mT Asia Besanosaurus Dal Sasso Pinna 1996 Valid mT Europe Brachypterygius von Huene 1922 Valid lJ Europe A lJ Ophthalmosaurid closely related to Platypterygius and Caypullisaurus. Fossils have been found in England and European Russia. Californosaurus Kuhn 1934 Valid lT N. America A 3-meter teretocnemid who is also the basal-most known Euichthyosaurian. Its remains were first recovered from the Carnian Lower Hosselkus Limestone of California. Californosaurus has also been known as Shastasaurus perrini and Delphinosaurus perrini. Callawayia Maische Matzke 2000 Valid Cartorhynchus Motani et al. 2015 Valid eT Asia Non-ichthyosaur ichthyosauriform Catutosaurus Fernández et al. 2021 Valid lJ South America Caypullisaurus Fernández 1997 Valid lJ to eK S. America A large ophthalmosaurid closely related to Platypterygius and Brachypterygius. It was discovered in strata dating to the lJ - eK of Argentina. Chacaicosaurus Fernández 1994 Valid S. America A Bajocian genus whose fossils have been found in Argentina. Possibly a stenopterygiid. Chaohusaurus Young Dong 1972 Valid eT Asia A primitive ichthyosaur that retained a lizard-like body discovered in Chaohu, China. It was also one of the smallest ichthyosaurs, being from 70 to 180 cm long and an estimated weight of 10 kg. Chensaurus Mazin Suteethorn Buffetaut Jaeger Helmcke-Ingavat 1991 Jr. synonym N/A N/A Junior synonym of Chaohusaurus. Chonespondylus Leidy 1868 Valid mT Contectopalatus Maische Matzke 1998 Disputed mT Europe A strange mT mixosaurid with a high crest of bone on its head and a 5-meter body. It was thought to be a Mixosaurus species for some time until given its own genus in 1998. Some experts have felt that the splitting was unjustified. Cryopterygius Druckenmiller et al. 2012 Valid lJ Europe Cymbospondylus Leidy 1868 Valid eT to mT One of the largest ichthyosaurs, adults ranged in length from 6 m (20 ft) up to 10 m (33 ft) long. It was one of the least fish-like of the ichthyosaurs, lacking a dorsal fin and fluked tail. Consequently, Cymbospondylus probably swam by wriggling its body from side to side like a modern sea snake. Dearcmhara Brusatte et al. 2015 Valid eJ to mJ Europe Delphinosaurus Merriam 1905 Jr. synonym N/A N/A Junior synonym of Californosaurus. Eretmorhipis Chen et al. 2015 Valid eT Asia Non-ichthyosaur ichthyopterygian Eurhinosaurus Abel 1909 Valid eJ Europe A genus exceeding 6 m in length from the Sinemurian to Toarcian of England and Germany. Eurhinosaurus was built like a regular ichthyosaur, with a fish-like body including a large eyes, dorsal and caudal fins, but had one distinct feature that set it apart from other ichthyosaurs; its upper jaw was twice as long as the lower jaw and covered with sidewards-pointing 'teeth', like a sawfish's. Eurypterygius Jaekel 1904 Jr. synonym N/A N/A Junior synonym of Ichthyosaurus. Excalibosaurus McGowan 1986 Valid eJ Lived during the Sinemurian stage in what is now England. It is characterized by the extreme elongation of the rostrum, giving the animal a swordfish-like look. Excalibosaurus is known from two skeletons. The holotype was from a juvenile with an estimated body length of 4 m. The estimated body length of the second specimen, discovered in 1996, is 7 m. Gengasaurus Paparella et al. In press In press lJ Europe Grendelius McGowan 1976 Jr. synonym N/A N/A Junior synonym of Brachypterygius. Grippia Wiman 1930 Valid eT Asia Greenland Japan N. America A small ichthyosaur only 1-1.5 m long, its fossils have been found along the coasts of Greenland, China, Japan, and Canada. Guizhouichthyosaurus Cao Luo 2000 Valid lT Asia Gulosaurus Cuthbertson et al. 2013 Valid eT N. America A grippidian. The type species is Gulosaurus helmi. Hauffiopteryx Maisch 2008 Valid eJ Europe Himalayasaurus Young Dong 1972 Valid lT Asia Hudsonelpidia McGowan 1995 Valid lT Hupehsuchus Carroll Dong 1991 Valid mT Asia Non-ichthyosaur ichthyopterygian from the mT of China. The type species is H. nanchangensis. Ichthyosaurus De la Beche Conybeare 1821 Valid eJ Ichthyotitan Paul de la Salle 2016 Valid lT Europe The largest genus of ichthyosaur that we currently know of. Fossils of Ichthyotitan have been found in the Westbury Mudstone Formation in Somerset, England. Isfjordosaurus Motani 1999 Valid Non-ichthyosaur ichthyopterygian. Jabalisaurus Barrientos-Lara et al. 2021 Valid lJ North America Janusaurus Roberts et al. 2014 Valid lJ Europe An ophthalmosaurid ichthyosaur. The type species is Janusaurus lundi. Kazakhstanosaurus Bolatovna Makustovich 2021 Valid lJ Asia Keilhauia Delsett et al. 2017 Valid eK Europe An ophthalmosaurid ichthyosaur. The type species is Keilhauia nui. Kyhytysuka Cortés et al. 2021 Valid eK South America Leninia Fischer et al. 2014 Valid eK Europe An ophthalmosaurine ophthalmosaurid ichthyosaur. The type species is Leninia stellans. Leptocheirus Merriam 1903 Jr. synonym N/A N/A Junior synonym of Toretocnemus. Leptonectes McGowan 1996 Valid Europe Lived from the Rhaetian to Pliensbachian in what is now Belgium, England and Germany. Leptopterygius Huene 1922 Valid lT to eJ Macgowania Motani 1999 Valid Macropterygius Huene 1923 Jr. synonym N/A N/A Junior synonym of Aegirosaurus. Magnipterygius Maisch Matzke 2022 Valid eJ Europe Maiaspondylus Maxwell Caldwell 2006 Valid lK N. America Malawania Fischer et al. 2013 Valid eK Asia A basal member of Thunnosauria. The type species is Malawania anachronus. Merriamia Boulenger 1904 Jr. synonym N/A N/A Junior synonym of Toretocnemus. Metashastasaurus Nicholls Manabe 2001 Jr. synonym N/A N/A Junior synonym of Callawayia. Mikadocephalus Maisch Matzke 1998 Valid Europe Mixosaurus Baur 1887 Valid mT Mollesaurus Fernandez 1999 Valid mJ S. America Myopterygius von Huene 1922 Syn. Synonym of Platypterygius. Muiscasaurus Maxwell Dick Padilla Parra 2015 Valid eK S. America Nanchangosaurus Wang 1959 Valid mT Nannopterygius Huene 1922 Valid lJ Europe Nannopterygius is a genus of ophthalmosaurid ichthyosaur that lived in from the Kimmeridgian to Tithonian. Fossils have been found in England and Germany. Omphalosaurus Merriam 1906 Valid eT Europe An extinct genus of marine reptile from Spitsbergen. It has been considered an ichthyopterygian, however a study by Motani in 2000 showed that it lacks the basal synapomorphies of Ichthyopterygia. As such, its exact position in the diapsid tree is currently unknown. Ophthalmosaurus Seeley 1874 Valid mJ to lJ Europe N. America S. America Otschevia Efimov 1997 Jr. synonym N/A N/A Junior synonym of Brachypterygius. Pachygonosaurus von Huene 1916 Nomen dubium Palvennia Druckenmiller et al. 2012 Valid lJ Europe Panjiangsaurus Chen Chang 2003 Jr. synonym N/A N/A Junior synonym of Guizhouichthyosaurus. Parahupehsuchus Chen et al. 2014 Valid eT Asia Paraophthalmosaurus Arkhangelsky 1997 Jr. synonym N/A N/A Junior synonym of Ophthalmosaurus. Parrassaurus Barrientos-Lara Alvarado-Ortega 2021 Valid lJ North America Parvinatator Nicholls Brinkman 1995 Valid Non-ichthyosaur ichthyopterygian. Pessopteryx Wiman 1910 Valid Pessosaurus Wiman 1910 Valid mT Phalarodon Merriam 1910 Valid mT Asia Phantomosaurus Maisch Matzke 2000 Valid Platypterygius Kuhn 1946 Valid lK Plutoniosaurus Efimov 1997 Jr. synonym N/A N/A Junior synonym of Platypterygius. Proteosaurus Home 1819 Jr. synonym N/A N/A Junior synonym of Ichthyosaurus. Protoichthyosaurus Appleby 1979 Jr. synonym N/A N/A Junior synonym of Ichthyosaurus. Qianichthyosaurus Li 1999 Valid Quasianosteosaurus Maisch Matzke 2003 Valid eT Europe Sangiorgiosaurus Brinkmann 1998 Jr. synonym N/A N/A Junior synonym of Mixosaurus. Sclerocormus Jiang et al. 2016 Valid eT Asia Non-ichthyosaur ichthyopterygian. Shastasaurus Merriam 1895 Valid mT to lT Asia Europe N. America Shastasaurus is a genus of ichthyosaur from whose remains have been found in United States, Canada, Mexico, Austria, Italy, Switzerland, Germany, Spitsbergen and China. Shonisaurus Camp 1976 Valid lT ?Asia N. America One of the largest ichthyosaur genera that has yet been found. Fossils of Shonisaurus were first found in Nevada in 1920. It lived during the Norian stage of the late Triassic period and had a long pointed mouth that contained teeth only at the front end. S. popularis specimens reached a length of 15 meters (49 feet). A second species, S. sikanniensis, was later discovered in British Columbia and has an estimated length of 21 meters (69 feet). Simbirskia Otschev Efimov 1985 Valid Simbirskiasaurus Otschev Efimov 1985 Valid eK Sisteronia Fischer et al. 2014 Valid eK Europe A platypterygiine ophthalmosaurid ichthyosaur. The type species is Sisteronia seeleyi. Stenopterygius Jaekel 1904 Valid eJ Europe Lived from the Toarcian to Aalenian from England, France, Germany and Luxembourg. Maximum length was 4 m. One famous fossil is that of a mother and baby that died in childbirth. This proved that ichthyosaur infants were born tail-first, just like cetaceans, to prevent them from drowning before fully clearing the birth canal. Suevoleviathan Maisch 1998 Valid Sumpalla Campos et al. 2021 Valid lJ South America Svalbardosaurus Mazin 1981 Nomen dubium eT Sveltonectes Fischer Masure Arkhangelsky Godefroit 2011 Valid eK Europe Temnodontosaurus Lydekker 1889 Valid eJ Europe Lived from the Hettangian to Toarcian in England and Germany. It was a large genus, exceeded 12 meters (39 feet) in length. Temnodontosaurus eyes were approximately 20 cm (7.9 in) in diameter making them the largest of any known vertebrate. Thaisaurus Mazin Sutetthorn Buffetaut Jaeger Helmcke-Ignavat 1991 Valid Non-ichthyosaur ichthyopterygian. Thalassodraco Jacobs Martill 2020 Valid mJ Europe Thalattoarchon Fröbisch et al. 2013 Valid mT North America Tholodus von Meyer 1851 Valid mT Possibly Asia Europe Toretocnemus Merriam 1902 Valid lT Typicusichthyosaurus Yin et al. 2000 Jr. synonym N/A N/A Probable junior synonym of Guanlingsaurus, though poor preservation makes it difficult to tell Undorosaurus Efimov 1997 Valid lJ Russia Utatsusaurus Shikoma 1978 Valid eT Non-ichthyosaur ichthyopterygian. Wahlisaurus Lomax 2016 Valid eJ Europe Wimanius Maisch Matzke 1988 Valid Xinminosaurus Jiang et al 2008 Valid Possible synonym of Tholodus. Yasykovia Efimov 1999 Valid lJ Russia Formerly known as a synonym of Ophthalmosaurus.		Besanosaurus Californosaurus. Caypullisaurus. Chaohusaurus. Cymbospondylus. Eurhinosaurus. Excalibosaurus. Grippia. Hupehsuchus. Ichthyosaurus. Leptonectes. Mixosaurus. Ophthalmosaurus. Platypterigius. Shastasaurus. Shonisaurus. Stenopterygius. Temnodontosaurus. Utatsusaurus. Yasykovia.

See also

• Ichthyosaur
• Ichthyopterygia
• List of dinosaurs
• List of mosasaurs
• List of plesiosaurs
• List of pterosaurs
• List of ichthyosaur type specimens
• Timeline of ichthyosaur research

External links

• USMP Berkeley's ichthyosaur introduction
• Ryosuke Motani's detailed Ichthyosaur homepage, with vivid graphics
• Eureptilia: Ichthyosauria - Palaeos
• Ichthyosauria - cladogram (Mikko's Phylogeny Archive)
• Hauff Museum, Germany - exhibiting the finds of Holzmaden
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