Phylum Mollusca Linnaeus, 1758 - molluscs
   Class Cephalopoda Cuvier, 1795 - cephalopods
     Subclass Coleoida Bather, 1888 see Subclass Coleoidea Bather, 1888
       Order Teuthida Naef, 1916
         Suborder Oegopsida d'Orbigny, 1845 see Suborder Oegopsina Orbigny, 1845
           01 Family Lycoteuthidae Pfeffer, 1908
           02 Family Enoploteuthidae Pfeffer, 1900
           03 Family Octopoteuthidae Berry, 1912
           04 Family Onychoteuthidae Gray, 1849
           05 Family Gonatidae Hoyle, 1886
           06 Family Ctenopterygidae Grimpe, 1922 [monotypic] see Family Chtenopterygidae Grimpe, 1922
           07 Family Bathyteuthidae Pfeffer, 1900 [monotypic]
           08 Family Histioteuthidae Verrill, 1881 [monotypic]
           09 Family Psychroteuthidae Thiele, 1920 [monotypic]
           10 Family Architeuthidae Pfeffer, 1900 [monotypic]
           11 Family Neoteuthidae Naef, 1921
           12 Family Walvisteuthidae Nesis & Nikitina, 1986 [monotypic]
           13 Family Brachioteuthidae Pfeffer, 1908
           14 Family Ommastrephidae Steenstrup, 1857
           15 Family Thysanoteuthidae Keferstein, 1866 [monotypic]
           16 Family Lepidoteuthidae Pfeffer, 1912
           17 Family Batoteuthidae Young & Roper, 1968 [monotypic]
           18 Family Cycloteuthidae Naef, 1923
           19 Family Chiroteuthidae Gray, 1849
           20 Family Mastigoteuthidae Verrill, 1881
           21 Family Joubiniteuthidae Naef, 1922 [monotypic]
           22 Family Promachoteuthidae Naef, 1912 [monotypic]
           23 Family Grimalditeuthidae [monotypic] see Family Chiroteuthidae Gray, 1849
           24 Genus Parateuthis Thiele, 1920
           25 Family Cranchiidae Prosch, 1847