After Williams, G. S., 1999-2000

<==o †Ptychodontidae Jaekel, 1898
   |-- †Hemiptychodus Cret.
   |-- †Heteroptychodus Yabe & Obata, 1930; Cret.
   |-- †Hylaeobatis ornatus (Woodward, 1889) Woodward, 1916; L. Cret. Eu.
   `--o †Ptychodus Agassiz, 1835; L.Cret. NA. Eu. As. Af. Aust., U.Cret. SA.
      |-- †P. anonymus Williston, 1900
      |-- †P. bellucii Bonarelli, 1899
      |-- †P. chappelli Reinhart, 1951
      |-- †P. concentricus
      |-- †P. connellyi McLeod & Slaughter, 1980
      |-- †P. cyclodontis Mutter, Iturralde-Vinent & Carmona, 2005
      |-- †P. decurrens (Agassiz, 1848)
      |-- †P. latissimus (Agassiz, 1835)
      |-- †P. mammillaris (Agassiz, 1835)
      |-- †P. mantelli
      |-- †P. marginalis
      |-- †P. martini Williston, 1898
      |-- †P. mortoni Agassiz, 1843
      |-- †P. occidentalis (Leidy, 1868)
      |-- †P. oweni
      |-- †P. polygyrus (Agassiz, 1835)
      |-- †P. rugosus (Dixon, 1850)
      |-- †P. sp.
      `-- †P. whipplei (Marcov, 1858)

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