PBDB Taxon

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Rhynchocephalia (rhynchocephalian)

Osteichthyes - Rhynchocephalia

Taxonomy

Rhynchocephalia was named by Günther (1867). It is extant. It was considered monophyletic by Jones et al. (2013).

It was reranked as the subclass Rhynchocephala by Perrier (1928); it was reranked as the suborder Rhynchocephalia by Lortet (1892), Villa et al. (2021), Agnolín et al. (2024).

It was assigned to Squamata by Günther (1867); to Sauria by Lortet (1892); to Eoditremata by Hay (1930); to Diaptosauria by Osborn (1903), Osborn (1904), Roxo (1937); to Neosauromorpha by Huene (1954); to Lepidosauria by Olson (1966); to Lepidosauria by Haughton and Brink (1954), Haubold (1974); to Reptilia by Cope (1871), Cope (1875), Günther (1886), Zittel (1890), Woodward (1898), Hay (1902), Perrier (1928), Swinton (1934), Kuhn (1946), Kuhn (1964), Frank and Ramus (1996); to Lepidosauria by Kuhn (1966), Jones et al. (2013); to Diapsida by Osborn (1903), Skinner et al. (2020); to Lepidosauria by Gardiner (1982), Simon and Kellner (2003), Apesteguía (2005), Sues and Schoch (2021), Villa et al. (2021); and to Lepidosauria by Agnolín et al. (2024).

Subtaxa

Clarazisauria, Colobops, Eifelosaurus, Gephyrosauridae, Gephyrosaurus, Hamatopus, Pachystropheidae, Sauranodontes, Sphenodontidae (syn. Hatteriidae), Sphenodontiformes, Tholodontidae, Vadasaurus

Synonymy list

Year	Name and author
1867	Rhynchocephalia Günther p. 462
1871	Rhynchocephalia Cope p. 235
1875	Rhynchocephalia Cope p. 15
1886	Rhynchocephalia Günther p. 444
1890	Rhynchocephalia Zittel p. 450
1892	Rhynchocephalia Lortet p. 29
1898	Rhynchocephalia Woodward p. 141
1902	Rhynchocephalia Hay p. 459
1903	Rhynchocephalia Osborn p. 276
1904	Rhynchocephalia Osborn p. 112
1928	Rhynchocephala Perrier p. 3118
1930	Rhynchocephalia Hay p. 130
1934	Rhynchocephalia Swinton p. 47
1937	Rhynchocephalia Roxo p. 44
1946	Rhynchocephalia Kuhn p. 62
1954	Rhynchocephalia Haughton and Brink p. 4
1954	Rhynchocephalia Huene p. 59
1964	Rhynchocephalia Kuhn p. 312
1966	Rhynchocephalia Kuhn p. 36
1966	Rhynchocephalia Olson p. 301
1974	Rhynchocephalia Haubold p. 35
1982	Rhynchocephalia Gardiner p. 228
1996	Rhynchocephalia Frank and Ramus
2003	Rhynchocephalia Simon and Kellner p. 1
2005	Rhynchocephalia Apesteguía
2013	Rhynchocephalia Jones et al.
2020	Rhynchocephalia Skinner et al.
2021	Rhynchocephalia Sues and Schoch
2021	Rhynchocephalia Villa et al.
2024	Rhynchocephalia Agnolín et al. p. 2

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Rank	Name	Author
kingdom	Animalia	()
—	Bilateria
—	Eubilateria	Ax 1987
—	Deuterostomia
phylum	Chordata	Haeckel 1874
subphylum	Vertebrata
superclass	Gnathostomata
class	Osteichthyes
subclass	Sarcopterygii	()
subclass	Dipnotetrapodomorpha	(Nelson 2006)
subclass	Tetrapodomorpha	()
—	Tetrapoda
—	Reptiliomorpha
—	Anthracosauria
subclass	Amphibiosauria	Kuhn 1967

Rank	Name	Author
—	Cotylosauria	()
—	Amniota
—	Sauropsida
class	Reptilia
subclass	Eureptilia	()
—	Romeriida
—	Diapsida	()
—	Eosuchia	()
—	Neodiapsida
—	Sauria	Gauthier 1984
—	Lepidosauromorpha	(Benton 1983)
superorder	Lepidosauria	()
order	Rhynchocephalia
order	Rhynchocephalia

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.

Or. Rhynchocephalia Günther 1867 [rhynchocephalian]

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Subor. †Clarazisauria Hoffstetter 1955

Invalid names: Claraziidae Peyer 1936 [empty]

G. †Colobops Pritchard et al. 2018

†Colobops noviportensis Pritchard et al. 2018

G. †Eifelosaurus Jaekel 1904

†Eifelosaurus triadicus Jaekel 1904

Fm. †Gephyrosauridae Evans 1980

G. †Deltadectes Whiteside et al. 2017

†Deltadectes elvetica Whiteside et al. 2017

G. †Gephyrosaurus Evans 1980

†Gephyrosaurus bridensis Evans 1980

†Gephyrosaurus evansae Whiteside and Duffin 2017

G. †Hamatopus Lilienstern 1939

Fm. Sphenodontidae Cope 1871

G. †Ankylosphenodon Reynoso 2000

†Ankylosphenodon pachyostosus Reynoso 2000

Subfm. †Brachyrhinodontinae Huene 1948

Invalid names: Palacrodontinae Haughton 1924 [synonym]

G. †Cynosphenodon Reynoso 1996

†Cynosphenodon huizachalensis Reynoso 1996

G. †Derasmosaurus Barbera and Macuglia 1988

†Derasmosaurus pietrarojae Barbera and Macuglia 1988

G. †Eilenosaurus

G. †Elachistosuchus Janensch 1949

†Elachistosuchus huenei Janensch 1949

G. †Glevosaurus Swinton 1939

G. †Leptosaurus Fitzinger 1837

†Leptosaurus neptunius Goldfuss 1831

†Leptosaurus pulchellus Zittel 1887

G. †Oenosaurus Rauhut et al. 2012

†Oenosaurus muehlheimensis Rauhut et al. 2012

Unr. †Opisthodontia Apesteguía and Novas 2003

G. †Alamitosphenos Agnolín et al. 2023

†Alamitosphenos mineri Agnolín et al. 2023

Subfm. †Eilenodontinae Rasmussen and Callison 1981

G. †Eilenodon Rasmussen and Callison 1981

†Eilenodon robustus Rasmussen and Callison 1981

G. †Kaikaifilusaurus Simon and Kellner 2003

†Kaikaifilusaurus calvoi Simon and Kellner 2003

Invalid names: Priosphenodon avelasi Apesteguía and Novas 2003 [synonym]

†Kaikaifilusaurus minimus Apesteguia and Carballido 2014

G. †Patagosphenos Gentil et al. 2019

†Patagosphenos wataku Gentil et al. 2019

G. †Toxolophosaurus Olson 1960

†Toxolophosaurus cloudi Olson 1960

G. †Fraserosphenodon Herrera-Flores et al. 2018

†Fraserosphenodon latidens Fraser 1993

G. †Kawasphenodon Apesteguía 2005

†Kawasphenodon expectatus Apesteguía 2005

†Kawasphenodon peligrensis Apesteguía et al. 2014

G. †Priosphenodon Apesteguía and Novas 2003

G. †Sphenotitan Martinez et al. 2013

†Sphenotitan leyesi Martinez et al. 2013

G. †Trullidens Kligman et al. 2021

†Trullidens purgatorii Kligman et al. 2021

G. †Paleollanosaurus Heckert 2004

†Paleollanosaurus fraseri Heckert 2004

G. †Piocormus Wagner 1852

†Piocormus laticeps Wagner 1852

G. †Scharschengia Huene 1940

†Scharschengia enigmatica Huene 1940

G. †Sigmala Fraser 1986

†Sigmala sigmala Fraser 1986

G. †Simila

G. Sphenodon Gray 1831

Sphenodon guentheri Gunther 1867 [Brother island tuatara]

Sphenodon punctata Gray 1842 [tuatara]

Subfm. Sphenodontinae Cope 1871

G. †Navajosphenodon Simões et al. 2022

†Navajosphenodon sani Simões et al. 2022

G. †Notosphenos Agnolín et al. 2024

G. †Sphenofontis Villa et al. 2021

†Sphenofontis velserae Villa et al. 2021

G. †Tika Apesteguía et al. 2021

†Tika giacchinoi Apesteguía et al. 2021

Invalid names: Notosphenos finisterre Agnolín et al. 2024 [nomen dubium]

G. †Sphenovipera Reynoso 2005

†Sphenovipera jimmysjoyi Reynoso 2005

G. †Theretairus Simpson 1926

†Theretairus antiquus Simpson 1926

G. †Zapatadon Reynoso and Clark 1998

†Zapatadon ejidoensis Reynoso and Clark 1998

Invalid names: Hatteriidae Cope 1864 [synonym]

G. †Vadasaurus Bever and Norell 2017

†Vadasaurus herzogi Bever and Norell 2017

Invalid names: Pachystropheidae Kuhn 1961 [empty], Sauranodontes Lortet 1892 [empty], Sphenodontiformes Hay 1930 [empty], Tholodontidae Kuhn [empty]

Diagnosis

Reference	Diagnosis
H. F. Osborn 1903	Maxillaries and premaxillaries with teeth (excepting Sauranodon). Vertebrae perforate or imperforate. Sacrals 2. Caudals with "splitting point." Hypocentra present or absent. Interclavicle T-shaped. Large puboischiadic (thyroid) foramina. Ilium narrow. Entepi- and ectepicondylar foramina variable. Proximal tarsalia incliding 3 elements (tibiale, intermedium, fibulare) partly coalesced. Distal tarsalia no texceeding 4.