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Plesiosauria (plesiosaur)

Reptilia - Sauropterygia

Subtaxa
Aptychodon, Aptychodon cretaceus, Bathyspondylus, Cimoliasaurus lissaensis, Cimoliasaurus teplicensis, Cimoliosaurus nazarowi, Discosaurus planior, Discosaurus vetustus, Elasmosaurus intermedius, Elasmosaurus orientalis, Embaphias, Embaphias circulosus, Eoplesiosaurus, Eretmosaurus, Gymocetus, Hexatarsostinus, Hunosaurus fasseli, Iserosaurus littoralis, Lutkesaurus, Mauisaurus brachiolatus, Muraenosauridae, Namuncurania, Neoplesiosauria, Nothosaurops, Oligosimus grandaevus, Orophosaurus, Orophosaurus pauciporus, Peloneustes kanzleri, Piptomerus hexagonus, Piptomerus megaloporus, Piptomerus microporus, Piratosaurus plicatus, Plesiosauroidea, Plesiosaurus affinis, Plesiosaurus australis, Plesiosaurus balticus, Plesiosaurus bernardi, Plesiosaurus brachistospondylus, Plesiosaurus brevifemur, Plesiosaurus brevis, Plesiosaurus continuus, Plesiosaurus cycnodeirus, Plesiosaurus degenhardti, Plesiosaurus ellipsospondylus, Plesiosaurus euryspondylus, Plesiosaurus gouldii, Plesiosaurus hexagonalis, Plesiosaurus infraplanus, Plesiosaurus latispinus, Plesiosaurus levis, Plesiosaurus lockwoodii, Plesiosaurus megapleuron, Plesiosaurus microdeirus, Plesiosaurus mudgei, Plesiosaurus neocomiensis, Plesiosaurus nordmanni, Plesiosaurus ophiodeirus, Plesiosaurus pachyomus, Plesiosaurus phillipsi (syn. Plesiosaurus carinatus), Plesiosaurus planispondylus, Plesiosaurus planus, Plesiosaurus planus trigonalis, Plesiosaurus platydeirus, Plesiosaurus poecilospondylus, Plesiosaurus shirleyensis, Plesiosaurus subdepressus, Plesiosaurus traversii, Plesiosaurus truncatus, Plesiosaurus validus, Plesiosaurus winspitensis, Pliosauridae, Pliosauroidea (syn. Brachydeira), Pliosaurus planus, Polycotylus donicus, Polycotylus epigurgitis, Polycotylus orientalis, Polycotylus tenuis, Polycotylus ultimus, Polyptychodon, Polyptychodon neocomiensis, Rhaeticosaurus, Rhomaleosauridae (syn. Thaumatosauridae), Scarrisaurus, Stereosaurus cratynotus, Stereosaurus platyomus, Stereosaurus stenomus, Stratesaurus, Sulmosaurus, Taphrosaurus, Tremamesacleididae, Uronautes, Uronautes cetiformis

View classification of included taxa

Synonyms
Synonymy list
YearName and author
1835Plesiosauria de Blainville
1840Plesiosaurus pachyomus Owen p. 74
1840Plesiosaurus affinis Owen p. 86
1841Polyptychodon Owen
1841Polyptychodon continuus Owen p. 19 figs. Pl. 72, fig. 13
1842Polyptychodon Owen p. 156
1845Polyptychodon Meyer p. 283
1850Plesiosaurus bernardi Owen p. 396
1851Discosaurus vetustus Leidy p. 326
1851Polyptychodon continuus Owen p. 47 figs. plate 14, figs 4-6
1853Plesiosaurus pachyomus Owen
1854Plesiosaurus brevis Owen
1854Plesiosaurus levis Owen
1854Plesiosaurus truncatus Owen p. 59
1854Plesiosaurus megapleuron Owen p. 60
1854Plesiosaurus latispinus Owen p. 63
1854Plesiosaurus subdepressus Owen p. 63
1855Aptychodon cretaceus Reuss p. 86 figs. pl. 15
1860Plesiosaurus neocomiensis Campiche p. 42
1860Plesiosaurus planispondylus Damon
1861Plesiosaurus australis Owen p. 122
1861Plesiosaurus pachyomus Owen p. 244
1861Polyptychodon Owen p. 255
1864Plesiosaurus bernardi Owen p. 1
1864Plesiosaurus latispinus Owen p. 1
1864Plesiosaurus pachyomus Owen p. 1
1864Plesiosaurus planus Owen pp. 2-7 figs. plates 1-3
1864Plesiosaurus planus trigonalis Owen p. 6 figs. pl. 3, figs 1-4
1865Piratosaurus plicatus Leidy pp. 29, 116 figs. pl. 19, fig. 8
1869Plesiosaurus lockwoodii Cope p. 40
1869Elasmosaurus orientalis Cope p. 55
1869Cimoliasaurus latispinus Cope p. 266
1869Crymocetus barnardi Cope p. 266
1869Elasmosaurus orientalis Cope p. 266
1869Plesiosaurus continuus Eichwald p. 1274
1869Plesiosaurus nordmanni Eichwald p. 1276
1869Plesiosaurus cycnodeirus Seeley pp. xvii, 41
1869Plesiosaurus euryspondylus Seeley pp. xviii, 41
1869Plesiosaurus microdeirus Seeley pp. xviii, 40
1869Plesiosaurus ophiodeirus Seeley pp. xviii, 44
1869Plesiosaurus platydeirus Seeley pp. xviii, 41
1869Plesiosaurus poecilospondylus Seeley pp. xviii, 48
1869Stereosaurus cratynotus Seeley pp. xviii, 44
1869Stereosaurus platyomus Seeley pp. xviii, 43
1869Stereosaurus stenomus Seeley pp. xviii, 43
1870Taphrosaurus lockwoodii Cope p. 274
1870Plesiosaurus brachistospondylus Hulke pp. 611-612 figs. pl. 41, figs 7-9
1870Discosaurus planior Leidy
1870Discosaurus orientalis Leidy p. 22
1871Plesiosaurus ellipsospondylus Phillips
1871Plesiosaurus validus Phillips p. 370
1871Plesiosaurus infraplanus Phillips p. 374
1871Plesiosaurus hexagonalis Phillips p. 375
1871Plesiosaurus phillipsi Sauvage p. 21
1871Plesiosaurus winspitensis Seeley p. 185
1872Oligosimus grandaevus Leidy p. 40
1874Mauisaurus brachiolatus Hector pp. errata slip
1874Plesiosaurus australis Hector p. 338
1874Plesiosaurus traversii Hector p. 344
1874Polycotylus tenuis Hector p. 345
1874Mauisaurus latibrachialis Hector p. 350
1875Cimoliasaurus planior Cope
1875Plesiosaurus brevifemur Cope p. 256
1876Uronautes cetiformis Cope p. 346
1883Pliosaurus planus Hulke p. 59
1883Lutkesaurus Kiprijanoff p. 35
1884Plesiosaurus smithi Owen p. 4
1885Plesiosaurus balticus Schoder p. 297 figs. pl. 13, fig. 1; pl. 14, fig. 1
1887Piptomerus megaloporus Cope p. 564
1887Orophosaurus pauciporus Cope p. 565
1887Piptomerus hexagonus Cope p. 565
1887Piptomerus microporus Cope p. 565
1887Plesiosaurus degenhardti Koken p. 106
1889Polyptychodon Lydekker p. 172
1889Cimoliosaurus bernardi Lydekker p. 185
1889Cimoliosaurus tenuis Lydekker p. 188
1889Cimoliosaurus brachistospondylus Lydekker p. 200
1889Cimoliosaurus smithi Lydekker p. 215
1889Cimoliosaurus planus Lydekker p. 217
1889Cimoliosaurus australis Lydekker p. 220
1889Cimoliosaurus latispinus Lydekker p. 222
1889Cimoliosaurus neocomiensis Lydekker p. 223
1889Cimoliosaurus truncatus Lydekker p. 227
1892Polyptychodon Seeley p. 151
1894Embaphias circulosus Cope p. 111
1894Elasmosaurus intermedius Cope p. 112
1894Plesiosaurus mudgei Cragin p. 69 figs. 1-3 & pl. 1
1897Plesiosaurus gouldii Williston p. 57
1900Plesiosaurus shirleyensis Knight p. 115
1903Plesiosauria Osborn p. 276
1903Cimoliasaurus planior Williston p. 7
1903Plesiosaurus brevifemur Williston p. 7
1903Plesiosaurus gouldii Williston p. 7
1903Plesiosaurus mudgei Williston p. 7
1903Cimoliasaurus vetustus Williston p. 8
1903Elasmosaurus intermedius Williston p. 9
1903Elasmosaurus orientalis Williston p. 9
1903Oligosimus grandaevus Williston p. 10
1903Piratosaurus plicatus Williston p. 10
1903Taphrosaurus lockwoodii Williston p. 10
1903Orophosaurus pauciporus Williston p. 11
1903Piptomerus hexagonus Williston p. 11
1903Piptomerus megaloporus Williston p. 11
1903Piptomerus microporus Williston p. 11
1903Uronautes cetiformis Williston p. 11
1903Embaphias circulosus Williston p. 12
1904Plesiosauria Osborn p. 100
1905Cimoliasaurus lissaensis Fritsch p. 15 figs. pl. 6, figs 6-8
1905Iserosaurus litoralis Fritsch p. 20
1905Hunosaurus fasseli Fritsch p. 25 figs. 25–29; Pl. 7:1–4
1905Plesiosaurus kanzleri Koken p. 691 fig. 7
1906Cimoliasaurus orientalis Williston p. 227
1907Cimoliasaurus teplicensis Fritsch p. 1 fig. 1
1908Piratosaurus plicatus Williston p. 735
1910Plesiosauria Andrews p. 77
1910Plesiosauri Jaekel p. 335
1910Polyptychodon neocomiensis Schardt p. 335 figs. 1-2
1911Cimoliosaurus nazarowi Bogolubov
1911Polycotylus epigurgitis Bogolubov p. 316 figs. 9, figs 5-6
1911Polycotylus balticus Bogolubov p. 337
1911Polycotylus orientalis Bogolubov p. 339 figs. pl. 13, figs 1-3, 5-7, 9-11
1911Polycotylus ultimus Bogolubov p. 348 figs. pl. 12, figs 4-6
1911Cimoliosaurus nazarowi Bogolubov p. 379 figs. pl. 3, figs4, 8, 12
1911Muraenosaurus truncatus Sauvage pp. 186-215
1913Peloneustes kanzleri Linder p. 341
1915Trinacromerum orientale Pravoslavlev p. 13
1915Trinacromerum ultimum Pravoslavlev p. 14
1915Polycotylus donicus Pravoslavlev p. 17 figs. pl. 1
1937Plesiosauria Roxo p. 43
1940Polyptychodon White p. 465
1946Plesiosauria Kuhn p. 59
1960Plesiosauria Delair p. 52
1960Muraenosaurus truncatus Delair pp. 60-61
1960Colymbosaurus brachistospondylus Delair p. 64
1960Colymbosaurus megapleuron Delair p. 65
1960Scanisaurus nazarowi Persson pp. 447-459 figs. 6, 7
1963Polycotylus epigurgitis Persson p. 21
1963Polycotylus orientalis Persson p. 21
1963Polycotylus ultimus Persson p. 21
1963Polyptychodon Welles and Slaughter p. 131
1964Plesiosauria Antunes p. 133
1981Plesiosauria Brown p. 339
1981Plesiosauria Thurmond and Jones p. 138
1981Discosaurus vetustus Thurmond and Jones p. 140
1988Plesiosauria Carroll
1991Plesiosauria Bardet et al. p. 1346
1994Plesiosauria Rieppel p. 4
1997Polycotylus tenuis Adams p. 182
1997Plesiosauria Gasparini p. 136
2001Plesiosauria O'Keefe p. 19 fig. 20
2002Plesiosauria Gasparini et al.
2002Plesiosauria Sepkoski, Jr.
2002Polyptychodon Sepkoski, Jr.
2004Plesiosauria O'Keefe p. 973
2006Plesiosauria Druckenmiller and Russell p. 186
2008Plesiosauria Druckenmiller and Russell p. 6
2008Plesiosauria O'Keefe p. 665
2012Plesiosauria Vincent and Benson p. 1050
2013Plesiosauria Fabbri et al. figs. 2, 3A
2014Plesiosauria Benson and Druckenmiller figs. 2-3
2017Plesiosauria Serratos et al.
2017Plesiosauria Smith and Araújo
2017Plesiosauria Wintrich et al.

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RankNameAuthor
kingdomAnimalia()
Triploblastica
Nephrozoa
Deuterostomia
phylumChordataHaeckel 1847
subphylumVertebrata
superclassGnathostomata
Osteichthyes()
Sarcopterygii
subclassDipnotetrapodomorpha(Nelson 2006)
subclassTetrapodomorpha()
Tetrapoda()
Reptiliomorpha
RankNameAuthor
Anthracosauria
Batrachosauria()
Cotylosauria()
Amniota
Sauropsida
classReptilia
subclassEureptilia()
Romeriida
Diapsida()
orderSauropterygia
Pistosauria(Baur 1890)
Plesiosauria(de Blainville 1835)
Plesiosauria(de Blainville 1835)

If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.

Diagnosis
ReferenceDiagnosis
D. S. Brown 1981Sauropterygia in which the nasals are absent; paroccipital processes usually long and slender, meeting squamosal; post-temporal fenestrae large; stapes probably absent; thecodont, with new teeth developing lingual to old and moving buccally to replace them; overall length up to 14 meters; vertebral centra with paired nutritive foramina; coracoids, pubes and ischia developing into large ventral plates; epipodials becoming broader than long; hyperphalangy reaching a maximum of 17.
F. R. O'Keefe 2001"Maxilla/squamosal contact present; quadrate embayed anteriorly; parashenoid is exposed anterior to posterior interpterygoid vacuities on palate surface; cervical zygopophyses narrower than centrum width; dorsasl neural arches shorter than centrum height; zygosphene/zygantrum articulation absent; longitudinal pectoral bar present; lack of articulation between ilium and pubis; expanded distal propodials with dorsal trochanter/tuberosity; ulna distinctly lunate; shifted fifth metapodial present; hyperphalangy present."