After Williams, 1999-2000, and Cuny, Rieppel & Sander, 2001

<==o Synechodontiformes Duffin & Ward, 1993
   |?- †Mucrovenator minimus Cuny, Rieppel & Sander, 2001
   |?-o †Rhomphaiodon L.Trias. WEu.
   |  |-- †R. nicolensis Duffin, 1993
   |  `-- †R. minor
   |--o Protospinacidae Woodward, 1919 
   |  `--o †Protospinax Jur. Eu.
   |     |-- †P. annectans
   |     `-- †P. sp.
   |--o Orthacodidae Glickman, 1957 
   |  `--o Sphenodus [Eychlaodus, Orthacodus] L. Jur. Eu.; U. Jur. Eu.; U. Cret Eu.; Pal. Eu.
   |     |-- †S. alpinus (Guembel, 1861)
   |     |-- †S. dubrisiensis
   |     |-- †S. helviticus Beaumont, 1960
   |     |-- †S. longidens Agassiz, 1843
   |     |-- †S. lundgreni (Davis, 1890)
   |     |-- †S. nitidus Wagner, 1863
   |     |-- †S. stschurowskii Kiprijanoff, 1880
   |     |-- †S. sp.
   |     |-- †S. tithunius Gemmelaro, 1868
   |     `-- †S. venulosus (Chabakov & Zonov, 1935)
   `--o Palaeospinacidae Regan, 1906
      |--o †Paraorthacodus U. Jur. NA. Eu. U. Cret. NA. Eu. SA.? NZ. Pal. NA. NZ. Eoc. NA.
      |  |-- †P. andersoni (Case, 1978)
      |  |-- †P. clarkii (Eastman, 1901)
      |  |-- †P. conicus (Davis, 1890)
      |  |-- †P. eocaenus (Leriche, 1902)
      |  |-- †P. jurensis (Schweizer, 1964)
      |  |-- †P. kruckowi (Theis, 1983)
      |  |-- †P. nerviensis (Leriche, 1929)
      |  |-- †P. patagonicus (Ameghino, 1893)
      |  |-- †P. recurvus (Trautschold, 1877)
      |  |-- †P. sp. cf. P. recurvus
      |  |-- †P. sp.
      |  |-- †P. sulcatus (Davis, 1888)
      |  `-- †P. validus (Chapman, 1918)
      |--o †Synechodus Woodward, 1880 [Paleospinax] L. Jur. Eu. U. Jur. Eu. L. Cret. Eu. U. Cret. NA. Eu. CAs. As. Aust. Pal. Eu.
      |  |-- †S. antiquus Ivanov, 2005
      |  |-- †S. dispar (Ruess, 1845)
      |  |-- †S. sp. cf. S. dispar
      |  |-- †S. dubrisiensis (Mackie, 1863) [Hypodus dubrisiensis Mackie, 1863] [type]
      |  |-- †S. enniskilleni (Egerton, 1872)
      |  |-- †S. faxensis (Davis, 1890)
      |  |-- †S. hesbayensis Casier, 1943
      |  |-- †S. ingrementum
      |  |-- †S. lerichei Herman, 1977
      |  |-- †S. multinodosus
      |  |-- †S. nitidus Woodward, 1910
      |  |-- †S. occultidens Duffin & Ward, 1993
      |  |-- †S. pinnai (Duffin, 1989)
      |  |-- †S. rhaeticus Duffin, 1981
      |  |-- †S. riegrafi (Theis, 1983)
      |  |-- †S. sp.
      |  |-- †S. striatus Case, 1978
      |  |-- †S. triangulatus Yamagishi, 2003
      |  |-- †S. tenuis (Woodward, 1889)
      |  |-- †S. turneri
      |  `-- †S. volaticus 
      `--o †Welcommia Jur. Eu. L. Cret, Eu.
         |-- †W. bodeuri Capetta
         |-- †W. politus Thies
         `-- †W. terencei

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