Phylum Mollusca Linnaeus, 1758 - molluscs
   Class Gastropoda Cuvier, 1795 - snails and slugs
     Subclass Opisthobranchia Milne-Edwards, 1848 - opisthobranchs see Order Opisthobranchia Milne-Edwards, 1848
       Order Acochlidioidea Küthe, 1935 [monotypic] see Order Acochlidia Odhner, 1937
         Superfamily Euacochlidioidea nom. inval.
           Family Tantulidae Rankin, 1979 [monotypic]
             Genus Antulum Millard, 1996, orth. inval. see Genus Tantulum Rankin, 1979