This list of plesiosaurs is a comprehensive listing of all genera that have ever been included in the order Plesiosauria, 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 plesiosaurs. The list currently includes 208 genera.

Scope and terminology

There is no official, canonical list of plesiosaur genera but one of the most thorough attempts can be found on the Plesiosauria section of Mikko Haaramo's Phylogeny Archive;^[1] also pertinent is the Plesiosaur Genera section at Adam Stuart Smith's Plesiosaur Directory.^[2]

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
Abyssosaurus^[3]	Berezin	2011	Valid	eK	Europe
Acostasaurus^[4]	Gómez-Pérez Noè	2017	Valid	eK	South America
Albertonectes^[5]	Kubo Mitchell Henderson	2012	Valid	lK	North America
Alexandronectes	Otero et al.	2016	Valid	lK	Australasia
Alexeyisaurus	Sennikov Arkhangelsky	2010	Valid	lT	Europe
"Alzadasaurus"	Welles	1943
Anguanax^[6]	Cau Fanti	2015	Valid	lJ	Europe
Anningasaura^[7]	Vincent Benson	2012	Valid	eJ	Europe
Apatomerus	Williston	1903	Valid	eK
Aphrosaurus	Welles	1943	Valid	lK
"Apractocleidus"	Smellie	1916	Jr. synonym			Junior synonym of Cryptoclidus.
Aptychodon	Reuss	1855	Valid	lK
Archaeonectrus	Owen	1865	Valid	eJ	Europe
Arminisaurus	Sachs Kear	2018	Valid	eJ	Europe
Aristonectes	Cabrera	1941	Valid	lK	South America, Antarctica
Attenborosaurus	Bakker	1993	Valid	eJ	Europe
Atychodracon	Smith	2015	Valid		Europe
Avalonnectes^[8]	Benson Evans Druckenmiller	2012	Valid	eJ	Europe
Bathyspondylus	Delair	1982	Valid	lJ
Bishanopliosaurus	Dong	1980	Valid	eJ
Bobosaurus	Dalla Vecchia	2006	Valid	lT
Borealonectes	Sato Wu	1980	Valid	mJ
Brachauchenius	Williston	1903	Valid	eK to lK
Brancasaurus	Wegner	1914	Valid	eK
Brimosaurus	Leidy	1855	Valid	lK
Callawayasaurus	Carpenter	1999	Valid	eK
Cardiocorax^[9]	Araújo et al.	2015	Valid	lK	Africa
Ceraunosaurus	Thurmond	1968	Jr. synonym			Junior synonym of Trinacromerum.
Chubutinectes^[10]	O'Gorman et al.	2023	Valid	lK	South America
Cimoliasaurus	Leidy	1851	Valid	lK
Colymbosaurus	Seeley	1874	Valid	lJ
Crymocetus	Cope	1869	Valid	eK
Cryonectes^[11]	Vincent Bardet Mattioli	2013	Valid	eJ	Europe
Cryptoclidus	Seeley	1892	Valid	mJ	Europe
Discosaurus	Leidy	1851	Valid
Djupedalia^[12]	Knutsen Druckenmiller Hurum	2012	Valid	lJ	Europe
Dolichorhynchops	Williston	1903	Valid		North America
Dravidosaurus	Yadagiri Ayyasami	1979	Nomen dubium	lK	Asia	Possibly a stegosaurian dinosaur
Eardasaurus	Ketchum Benson	2022	Valid	mJ	Europe
Edgarosaurus	Druckenmiller	2002	Valid	eK	North America
Eiectus	Noè Gómez-Pérez	2021	Valid	eK	Australia
Elasmosaurus	Cope	1868	Valid		North America Asia
Eoplesiosaurus^[8]	Benson Evans Druckenmiller	2012	Valid	eJ	Europe
Eopolycotylus^[13]	Albright Gillette Titus	2007	Valid
Eretmosaurus	Seeley	1874	Valid
Eromangasaurus	Kear	2005	Valid
Eurycleidus	Andrews	1922	Valid
Eurysaurus	Gaudry	1878	Valid
Fluvionectes	Campbell et al.	2021	Valid	lK	North America
Franconiasaurus^[14]	Sachs Eggmaier Madzia	2024	Valid	eJ	Europe
Fresnosaurus	Welles	1943	Valid
Futabasaurus	Sato Hasegawa Manabe	2006	Valid	lK	Asia	Also a theropod nomen nudum ("Futabasaurus").
Gallardosaurus	Gasparini	2009	Valid
"Georgia"	Otschev	1976	Preoccupied			Preoccupied by a genus of mollusk, renamed Georgiasaurus.
Georgiasaurus	Otschev	1878	Valid
Goniosaurus	Meyer	1860^{[citation needed]}	Valid
Gronausaurus^[15]	Hampe	2013	Valid	eK	Europe
Hastanectes^[16]	Benson et al.	2012	Valid	eK	Europe
Hauffiosaurus	O'Keefe	2001	Valid
Hydralmosaurus	Welles	1943	Valid
Hydrorion	Grobmann	2006	Valid
Hydrotherosaurus	Welles	1943	Valid	lK	North America
Ischyrodon	von Meyer	1838	Jr. synonym			Junior synonym of Liopleurodon.
Jucha	Fischer et al.	2020	Valid	eK	Europe
Kaiwhekea	Cruickshank Fordyce	2002	Valid	lJ	Europe
Kawanectes^[17]	O'Gorman	2016	Valid	lK	South America
Kimmerosaurus	Brown	1981	Valid
Kronosaurus	Longman	1924	Valid		Australia, South America
Lagenanectes	Sachs Hornung Kear	2017	Valid	eK	Europe
Leivanectes	Páramo-Fonseca O'Gorman Gasparini Padilla Parra Ruge	2019	Valid	eK	South America
Leptocleidus	Andrews	1922	Valid	eK	Europe, Africa, Australia
Leurospondylus	Brown	1913	Valid
Libonectes	Carpenter	1997	Valid
Lindwurmia	Vincent Storrs	2019	Valid	eJ	Europe
Liopleurodon	Sauvage	1873	Valid
Lorrainosaurus	Sachs et al.	2023	Valid	mJ	Europe	Originally assigned to Simolestes.^[18]
Luetkesaurus	Kiprijanoff	1883	Valid
Luskhan	Fischer et al.	2017	Valid	eK	Europe
Lusonectes	Smith Araújo Mateus	2011	Valid	eJ	Europe
Macroplata	Swinton	1930	Valid	eJ	Europe
Makhaira^[19]	Fischer et al.	2015	Valid	eK
Manemergus	Buchy Metayer Frey	2005	Valid
Marambionectes^[20]	O'Gorman et al.	2024	Valid	lK	Antarctica
Maresaurus	Gasparini	1997	Valid
Marmornectes	Ketchum Benson	2011	Valid	mJ	Europe
Martinectes^[21]	Clark O’Keefe Slack	2024	Valid	lK	North America
Mauisaurus	Hector	1874	Valid
Mauriciosaurus	Frey et al.	2017	Valid	lK	North America
Megacephalosaurus^[22]	Schumacher Carpenter Everhart	2013	Valid	lK	North America
Megalneusaurus	Knight	1898	Valid
Meyerasaurus	Smith Vincent	2010	Valid	eJ	Europe
Microcleidus	Watson	1911	Valid	eJ
Monquirasaurus	Noè Gómez-Pérez	2021	Valid	eK	South America
Morenosaurus	Welles	1943	Valid
Morturneria	Chatterjee Creisler	1994	Jr. synonym			Junior synonym of Aristonectes.
Muraenosaurus	Seeley	1874	Valid	mJ	Europe
Nakonanectes	Serratos Druckenmiller Benson	2017	Valid	lK	North America
Nichollssaura^[23]	Druckenmiller Russell	2009	Valid	eK	North America
"Nichollsia"	Druckenmiller Russell	2008	Preoccupied			Preoccupied by a genus of isopod, renamed Nichollssaura.
Occitanosaurus	Bardet Fernandez Garcia-Ramos Superbiola Pinuela Ruiz-Omenaca Vincent	2008	Valid
Ogmodirus	Williston Moodie	1917	Valid
Opallionectes	Kear	2006	Valid
Ophthalmothule	Roberts et al.	2020	Valid	lJ-eK	Europe
Orophosaurus	Cope	1851	Valid
Pachycostasaurus	Cruickshank Martill	1996	Valid
Pahasapasaurus	Schumacher	2007	Valid
"Palmula"^[13]	Albright Gillette Titus	2007	Preoccupied			Preoccupied by a genus of foraminifer, renamed Palmulasaurus.
Palmulasaurus	Albright Gillete Titus	2007	Valid
Pantosaurus	Marsh	1893	Valid
Peloneustes	Lydekker	1889	Valid	mJ	Europe
Peyerus	Stromer	1935	Jr. synonym			Junior synonym of Leptocleidus.
Picrocleidus	Andrews	1909	Jr. synonym			Junior synonym of Muraenosaurus.
Piptomerus	Cope	1887	Valid
Piratosaurus	Leidy	1865	Valid
Plesioelasmosaurus	Schumacher Everhart	2022	Valid	lK	North America
Plesiopharos	Puértolas-Pascual et al.	2021	Valid	eJ	Europe
Plesiopleurodon	Carpenter	1996	Valid
Plesiopterys	O'Keefe	2004	Valid
Plesiosaurus	Conybeare	1821	Valid	eJ	Europe
Pliosaurus	Owen	1841	Valid
Polycotylus	Cope	1869	Valid
Polyptychodon	Owen	1841	Valid
Rhaeticosaurus^[24]	Wintrich et al.	2017	Valid	lT	Europe
Rhomaleosaurus	Seeley	1871	Valid	eJ	Europe
Sachicasaurus	Páramo-Fonseca Benavides-Cabra Gutiérrez	2018	Valid	eK	South America
Scalamagnus^[21]	Clark O’Keefe Slack	2024	Valid	lK	North America
Scanisaurus	Persson	1959	Valid
Seeleyosaurus	White	1940	Valid	eJ	Europe
Serpentisuchops	Persons Street Kelley	2022	Valid	lK	North America
Simolestes	Andrews	1909	Valid
Sinopliosaurus	Young	1944	Valid	eK
Spitrasaurus^[25]	Knutsen Druckenmiller Hurum	2012	Valid	lJ	Europe
Spondylosaurus	Fisher	1845	Jr. synonym			Junior synonym of Pliosaurus.
Stratesaurus^[8]	Benson Evans Druckenmiller	2012	Valid	eJ	Europe
Sulcusuchus	Gasparini Spalletti	1992	Valid	lK	South America
Stenorhynchosaurus	Páramo et al.	2016	Valid	eK	South America
Stereosaurus	Seeley	1869	Valid
Sthenarosaurus	Watson	1911	Valid	eJ
"Stretosaurus"	Tarlo	1959	InValid			Type specimen is undiagnostic and should be assigned to Thalassophonea indeterminate.^[26]^[27]
Strongylokrotaphus	Novozhilov	1964	Jr. synonym			Junior synonym of Pliosaurus.
Styxosaurus	Welles	1952	Valid	lK	North America
Taphrosaurus	Cope	1870	Valid	lK
"Tatenectes"^[28]	Knight	1900	Valid
Terminonatator	Sato	2003	Valid	lK
Thalassiodracon	Storrs Taylor	1996	Valid	lT-eJ	Europe
Thalassiosaurus	Welles	1953	Jr. synonym			Junior synonym of Styxosaurus.
Thalassomedon	Welles	1943	Valid	lK	North America
Thalassonomosaurus	Welles	1943	Jr. synonym			Junior synonym of Styxosaurus.
Thaumatodracon	Smith Araújo	2017	Valid	lK	Europe
"Thaumatosaurus"	Meyer	1841	InValid			Holotype is not diagnostic and can be referred to Pliosauroidea indet at best.
Thililua	Bardet Suberbiola Jalil	2003	Valid	lK
"Tremamesacleis"	White	1940	Jr. synonym			Junior synonym of Muraenosaurus.
Trematospondylus	Quenstedt	1858	Nomen dubium	mJ	Europe
Tricleidus	Andrews	1909	Valid
Trinacromerum	Cragin	1888	Valid	lK	North America
Tuarangisaurus	Wiffen Moisley	1986	Valid	lK
"Turneria"	Chatterjee Small	1989	Preoccupied			Preoccupied by a genus of ant, renamed Morturneria which is now recognised as a junior synonym of Aristonectes.
Umoonasaurus	Kear Schroeder Lee	2006	Valid	eK	Australia
Unktaheela^[21]	Clark O’Keefe Slack	2024	Valid	lK	North America
Uronautes^[29]	Cope	1870	Valid	lK
Vectocleidus^[16]	Benson et al.	2012	Valid	eK	Europe
Vegasaurus^[30]	O'Gorman Salgado Olivero Marenssi	2015	Valid	lK	Antarctica
Vinialesaurus^[31]	Gasparini Bardet Vinent Iturralde	2002	Valid	lJ
Westphaliasaurus	Schwermann Sander	2011	Valid	eJ	Europe
Woolungasaurus	Persson	1960	Valid	eK
Wunyelfia	Otero Soto-Acuña	2020	Valid	lK	South America
Yuzhoupliosaurus^[32]	Zhang	1985	Valid	mJ^[32]
"Zahrisaurus"	Malkani	2019	Dubious	lK	Asia
Zarafasaura	Vincent Pereda-Suberbiola Bouya Amaghzaz Meslouh	2011	Valid	lK	Africa

Styxosaurus

Scope and terminology

The list

See also

Footnotes

References