After Wu, 1994, Evans et al., 2001, Apesteguia & Novas, 2003, Bonaparte & Sues, 2006, and Apesteguia & Carballido, 2014

<==o Sphenodontida Estes, 1983 sensu Wu, 1994 [Rhynchocephalia Günther, 1867] (Sphenodontians; alkuliskot)
   |-- †Gephyrosaurus bridensis Evans, 1980 [paraphyletic Gephyrosauridae]
   `--o Sphenodontia Williston, 1925
      |?- Sphenodontia genera et species indet. [Richmond basin, Virginia, USA]
      |-- †Diphydontosaurus avonis Whiteside, 1986 [paraphyletic Gephyrosauridae]
      `--+--o †Planocephalosaurus Fraser, 1982 [paraphyletic Gephyrosauridae]
         |  |-- †P. robinsonae Fraser, 1982
         |  `-- †P. lucasi Heckert, 2004
         |--o †Pleurosauridae Lydekker, 1888
         |  |-- †Palaeopleurosaurus posidonae Carroll, 1985
         |  `--o †Pleurosaurus Meyer
         |     |-- †P. goldfussi
         |     `-- †P. ginsburgi
         `--o Sphenodontidae Cope, 1896 [1870] sensu lato (sphenodontids, tuataras; tuatarat)
            |-- †Rebbanasaurus jaini Evans, Prasad & Manhas, 2001
            `--+--+-- †Sphenocondor gracilis Apesteguía, Gómez & Rougier, 2012
               |  `-- †Godavarisaurus leteefi Evans, Prasad & Manhas, 2001
               `--+--o †Clevosauridae Bonaparte & Sues, 2006 [“Clevosaurinae” sensu Wu, 1994]
                  |  |-- †Polysphenodon mulleri Jaekel, 1911 [Polysphenodontinae Kuhn, 1969]
                  |  `--+-- †Brachyrhinodon taylori v. Huene, 1910
                  |     `--o †Clevosaurus Swinton, 1939 [Glevosaurus sensu Murry, 1987] [incl. Asiacephalosaurus; Rarojugalosaurus; Dianosaurus Young, 1982] L.Trias.-E.Jur. WEu. ENAm. EAs.
                  |        |?- †C. convallis Säilä, 2005
                  |        |?- †C. minor Fraser, 1988
                  |        |?- †C. sp. [England] [Fraser, 1988]
                  |        |?- †C.? sp. [South Africa] [Gow & Raath, 1977]
                  |        |?- †C. sp. [South Africa] [Sues & Reisz, unpubl. data (Sues, Shubin & Olson, 1994)]
                  |        |?- †c. brasiliensis Bonaparte & Sues, 2006
                  |        `--+--+-- †C. petilus (Young, 1982) [Dianosaurus petilus Young, 1982]
                  |           |  `-- †C. hudsoni Swinton, 1939
                  |           `--+?- †C. wangi Wu, 1994 [Asiacephalosaurus wangi (Wu)]
                  |              |-- †C. bairdi Sues, Shubin & Olsen, 1994 [was C. sp. (Sues, Shubin & Olsen)]
                  |              `-- †C. mcgilli Wu, 1994 [Rarojugalosaurus mcgilli]
                  `--o Sphenodontidae Cope, 1896 [1870] sensu stricto? [Sphenodontinae (Cope, 1896 [1870]) Nopcsa, 1928 sensu Wu, 1994]
                     |--o †Homoeosaurus Meyer, 1850
                     |  |?- †H. pulchellus
                     |  |-- †H. maximiliani
                     |  `-- †H. solnhofeni Cocude-Michel, 1963
                     `--+--o †Kallimodon Cocude-Michel, 1963
                        |  |-- †K. pulchellus [= Homoeosaurus pulchellus??]
                        |  `-- †K. cerinesis
                        `--+--o “Sapheosaurini”
                           |  |-- †Ankylosphenodon pachyostosus Reynoso, 2000
                           |  `--o †Sapheosaurus von Meyer, 1850 [Piocormus]
                           |     |-- †S. thiollierei Meyer, 1850
                           |     `-- †S. laticeps Wagner [Piocormus laticeps]
                           `--+-- †Pamizinsaurus tlayuaensis Reynoso, 1997
                              `--+--o Sphenodontinae (Cope, 1896) sensu Rauhut, Heyng, López-Arbarello & Hecker, 2012, and Cau, Baiano & Raia, 2014
                                 |  |--+-- †Zapatadon ejidoensis Reynoso & Clark, 1998
                                 |  |  |-- †Derasmosaurus pietraroiae Barbera & Macuglia, 1988 [Chometokadmon Costa, 1864 (in partim)] L.Cret. SEu.
                                 |  |  `-- †Oenosaurus muehlheimensis Rauhut, Heyng, López-Arbarello & Hecker, 2012
                                 |  `--o Sphenodontini Cope, 1896 [1870]
                                 |     |-- †Cynosphenodon huizachalensis Reynoso, 1996
                                 |     |--o Sphenodon Gray, 1831 (tuataras; tuatarat)
                                 |     |   |?- cf.S. sp. E.Mioc. NZ. (Jones et al., 2009)
                                 |     |   |?- †S. diversum Colenso, 1885
                                 |     |   |-- S. guentheri Buller, 1877 (Brothers Island tuatara; pikkutuatara)
                                 |     |   `--o S. punctatus (Gray, 1842) (Northern tuatara; isotuatara, tuatara)
                                 |     |      |-- †S. p. reischeki
                                 |     |      |-- S. p. ssp. (Cook Strait tuatara; cookinsalmentuatara)
                                 |     |      `-- S. p. punctatus (northern tuatara)
                                 |     `--+-- †Sphenovipera jimmysjoyi Reynoso, 2005; M.Jur. SWNAm.
                                 |        `--+-- †Theretairus antiquus Simpson, 1926; U.Jur. NAm.
                                 |           `--o †Kawasphenodon Apesteguia, 2005; U.Cret.-L.Paleoc. SAm.
                                 |              |-- †K. expectatus Apesteguia, 2005
                                 |              `-- †K. peligrensis Apesteguía, Gómez & Rougier, 2014
                                 `--o Opisthodontia Apesteguia & Novas, 2003
                                    |-- †Opisthias rarus Gilmore, 1910 [Theretarius antiquus Simpson, 1926 (juv.)]; U.Jur. SWNAm.
                                    `--o †Eilenodontini Rasmussen & Callison, 1981 [Eilenodontinae Rasmussen & Callison, 1981]
                                       |--+-- †Kaikaifilusaurus calvoi Simon & Kellner, 2003
                                       |  `-- †Toxolophosaurus cloudi Olson, 1960 [non Throckmorton, Hopson & Parks, 1981]
                                       `--+-- †Eilenodon robustus Rasmussen & Callison, 1981
                                          `--o †Priosphenodon Apesteguia & Novas, 2003
                                             |-- †P. avelasi Apesteguia & Novas, 2003
                                             `-- †P. minimus Apesteguia & Carballido, 2014

Sphenodontia incertae sedis:

Sphenodontians yet unassignated to phylogeny.

Sphenodontidae gen. et sp. indet. [Evans & Sigogneau-Russell, 1997] [Early Cretaceous, Western North Africa]
    †Sphenodontidae gen. et sp. indet. [CMSN 5639] [Cau, Baiano & Raia, 2014] [Early Cretaceous, Pietraroia, Italy]
    †Sphenodontidae gen. et sp. indet. [MPN A01/82] [Cau, Baiano & Raia, 2014] [Early Cretaceous, Pietraroia, Italy]
    †Elachistosuchus hueni Janensch, 1949; U.Trias. CEu. [Elachistosuchoidea v. Huene, 1956; Elachistosuchidae Romer, 1966]Lamarquesaurus cabazai Apesteguia & Rougier, 2007; U.Cret. SAm.
    †Leptosaurus Fitzinger, 1837
        †Leptosaurus neptunius Fitzinger, 1837
        †Leptosaurus pulchellus Zittel 1887
    †Pelecymela Fraser, 1986 [=? Rebbanasaurus]
    †Paleollanosaurus fraseri Heckert, 2004
    †Sigmala sigmala Fraser, 1986 [Sigmala sigmala Fraser & Walkden, 1983 (nomen nudum)]; U.Trias. WEu.
    †Tingitana anoualae Evans & Sigogneau-Russell, 1997; L. Cret. WNAf.
    †Whitakersaurus bermani Heckert, Lucas, Rinehart & Hunt, 2008: L.Trias. SWNAm.

Alternative phylogenies of Sphenodontia

After Apesteguia & Carballido, 2014

<==o Rhynchocephalia
   |-- †Gephyrosaurus
   `--o Sphenodontia
      |-- †Diphydontosaurus
      `--+-- †Planocephalosaurus
         `--+-- †Rebbanasaurus
            `--+--+-- †Sphenocondor
               |  `-- †Godavarisaurus
               `--+--+-- †Brachyrhinodon
                  |  `-- †Clevosaurus
                  `--+-- †Palaeopleurosaurus
                     `--+--+-- †Kallimodon
                        |  `-- †Sapheosaurus
                        `--+-- †Theretairus
                           |-- †Sphenovipera
                           `--+-- †Homoeosaurus
                              |-- †Zapatodon
                              |-- †Cynosphenodon
                              |-- Sphenodon
                              |-- †Ankylosphenodon
                              `--o †Opisthodontia
                                 |-- †Kawasphenodon
                                 |-- †Opisthias
                                 `--o †Eilenodontinae
                                    |-- †Toxolophosaurus
                                    |-- †Eilenodon
                                    `-- †Priosphenodon

Reference(s):

  • Apesteguia, S. & Carballido, J. L., 2014: A New Eilenodontine (Lepidosauria, Sphenodontidae) from the Lower Cretaceous of Central Patagonia.
    –Journal of Vertebrate Paleontology: Vol. 34, #2, pp. 303-317 [doi: 10.1080/02724634.2013.803974]

After Rauhut, Heyng, López-Arbarello & Hecker, 2012

<==o Rhynchocephalia
   |-- †Gephyrosaurus
   `--o Sphenodontia
      |-- †Diphydontosaurus
      `--+-- †Planocephalosaurus
         `--o Sphenodontidae
            |--+-- †Homoeosaurus
            |  `--o “Clevosaurs”
            |     |-- †Brachyrhinodon
            |     |-- †Clevosaurus hudsoni
            |     `-- †Clevosaurus wangi
            `--+--o †Pleurosauridae
               |  |-- †Palaeopleurosaurus
               |  `-- †Pleurosaurus
               `--+--+-- †Kallimodon
                  |  `-- †Sapheosaurus
                  `--+--o Sphenodontinae
                     |  |-- Sphenodon
                     |  `--+-- †Oenosaurus
                     |     `--+-- †Cynosphenodon
                     |        `-- †Zapatodon
                     `--o †Opisthodontia
                        |-- †Opisthias
                        `--o †Eilenodontinae
                           |-- †Toxolophosaurus
                           `--+-- †Eilenodon
                              `-- †Priosphenodon

Reference(s):

  • Rauhut, O. W. M., Heyng, A. M., López-Arbarello, A. & Hecker, A., 2012: A New Rhynchocephalian from the Late Jurassic of Germany with a Dentition That Is Unique amongst Tetrapods.
    –Plos One: Vol. 7, #10, pp. e46839 [doi: 10.1371/journal.pone.0046839]

Reference(s):