After Hirayama, 1997, 1998, Moody, 1997, Hooks, 1998 and Lapparent de Broin, 2000

<==o Chelonioidea (Gray, 1825) Bauer, 1893 (Seaturtles; merikilpikonnat)
   |--o Dermochelyoidea (Gray, 1825) Baur, 1888 sensu Hirayama, 1997, 1998 (leatherback turtles and relatives; merinahkakilpikonnansukuiset merikilpikonnat)
   |  |?- †Cimochelys benstedi (Mantell, 1841) Zangerl, 1960 [taxonomic history]
   |  |?- †“Protostega” eaglefordensis Zangerl, 1953; L. Cret. NA.
   |  |?- †Thalassemyidae Rütimeyer, 1878
   |  `--o Dermochelyoidea sensu Hirayama 1998
   |     |-- Dermochelyidae Gray, 1825 (leatherback turtles; merinahkakilpikonnat)
   |     `--o Protostegidae Cope, 1872 sensu Hirayama 1998, and Lehman & Tomlinson, 2004
   |        |-- †Santanachelys gaffneyi Hirayama, 1998; L. Cret. ESA.
   |        `--+-- †Notochelone costata (Owen, 1882); L. Cret. Aust.
   |           |-- †Terlinguachelys fischbecki Lehman & Tomlinson, 2004; U.Cret. SWNA.
   |           `--+-- †Desmatochelyidae Williston, 1894 sensu Elliott, Irby & Hutchinson, 1997 and Moody, 1997
   |              `-- †Protostegidae Cope, 1872 sensu Moody, 1997, and Hooks, 1998
   `--o Cheloniidae Gray, 1825 sensu Hirayama, 1997 [Pan-Cheloniidae Joyce, Parham & Gauthier, 2004] (chelonians, seaturtles; merikilpikonnat)
      |-- †Toxochelyidae Baur, 1895 emend. Zangerl, 1953
      `--o Cheloniidae Gray, 1825 sensu lato
         |?- †“Thalassochelys” libyca Andrews, 1901
         |?- †“Thalassochelys” phosphatica De Stefano, 1903 [is a Bothremyid pleurodire]
         |?- †“Trachyaspis” cf. T. aegyptiana Lydekker, 1889
         |?- †Trachyaspis aegyptiana Lydekker, 1889 [Syllomus Cope, 1896]
         |?- †“Euclastes” douvillei De Stefano, 1902
         |--o †Lophochelyinae Zangerl, 1953 [Toxochelyidae:]
         |  |?-o †Lophochelys Zangerl, 1953
         |  |  |-- †L. natatrix Zangerl, 1953
         |  |  |-- †L. niobrarae Zangerl, 1953
         |  |  `-- †L. venatrix Zangerl, 1953
         |  |?- †Neurochelys Moody, 1980
         |  |?- †Oertelia gigantea (Oertel, 1914) Karl, Biermann & Tichy, 2012 [Toxochelys gigantea Oertel, 1914]
         |  |-- †Ctenochelys stenoporus (Hay, 1905); U. Cret. NA. WEu. [taxonomic history]
         |  `--+-- †Prionochelys nauta Zangerl, 1953 [?P. matutina Zangerl, 1953; P. galeotergum Zangerl, 1953]
         |     `--o †Peritresius Leidy, 1856 [taxonomic history]
         |        |-- †P. ornatus Baird, 1964 [taxonomic history]
         |        `-- †P. martini Gentry, Parham, Ehret & Ebersole, 2018
         `--+?- †“Catapleura” arcansaw Schmidt, 1944; U. Cret. NA.
            |--o †Euclastes Cope, 1867 [Osteopygidae sensu Hirayama, 1997] [taxonomic history]
            |  |-- †E. platyops Cope, 1867 [taxonomic history]
            |  |-- †E. wielandi (Hay, 1908) [taxonomic history]
            |  |-- †E. gosseleti (Dollo, 1886) [taxonomic history]
            |  |-- †E. meridionalis (de la Fuente & Casadío, 2000) [taxonomic history]
            |  |-- †E. planimenta (Owen, 1842) [taxonomic history]
            |  |-- †E. roundsi (Weems, 1988) [taxonomic history]
            |  `-- †E. hutchisoni Lynch & Parham, 2003 [taxonomic history]
            `-- Cheloniidae Gray, 1825 (Green turtles and relatives; merikilpikonnat)

After Lynch & Parham, 2003

<==o Cheloniidae sensu lato
   |-- †Toxochelys
   `--+-- †Lophochleyinae (sic)
      `--+--o †Euclastes
         |  |-- †E. gosseleti
         |  `-- †E. hutchisoni
         `--+-- †Argillochelys
            |-- †Puppigerus
            |-- †Eochelone
            `--o Cheloniidae sensu stricto
               |-- †Syllomus
               |-- Natator
               `--+?- †Procolpochelys
                  |-- Chelonia
                  |-- Eretmochelys
                  `--o Carettini
                     |-- Lepidochelys
                     `-- Caretta

Reference(s):

  • Lynch, S. C. & Parham, J. F., 2003: The first report of hard-shelled sea turtles (Cheloniidae sensu lato) from the Miocene of California, including a new species (Euclastes hutchisoni) with unusually plesiomorphic characters.
    –PaleoBios: Vol. 23, #3, pp. 21-35

Reference(s):