Kingdom Animalia Linnaeus, 1758 - animals
   Phylum Mollusca Linnaeus, 1758 - molluscs
     Subphylum Cyrtosoma Runnegar & Pojeta Jr., 1974 see Phylum Mollusca Linnaeus, 1758
       Class Cephalopoda Cuvier, 1795 - cephalopods
         Subclass Coleoidea Bather, 1888
           Genus Argonauta Linnaeus, 1758
           Order †Belemnitida Gray, 1849
           Genus Loligo Lamarck, 1798 - long-finned squid
           Genus Sepia Linnaeus, 1758
           Genus Spirula Lamarck, 1799