living organisms see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Superkingdom Eukaryotae see Domain Eukaryota Chatton, 1925
     Kingdom Animalia Linnaeus, 1758 - animals
       Subkingdom Eumetazoa Butschli, 1910 see [unranked] Eumetazoa Bütschli, 1910
         Phylum Mollusca Linnaeus, 1758 - molluscs
           Class Gastropoda Cuvier, 1795 - snails and slugs
             Subclass Prosobranchia Milne-Edwards, 1848 - prosobranchs see Class Gastropoda Cuvier, 1795
               Order Mesogastropoda Thiele, 1925 - mesogastropods see [unranked] mesogastropods
                 Superfamily Hipponicacea Troschel, 1861 see Superfamily Vanikoroidea Gray, 1840
                   Family Fossaridae Adams, 1860 see Subfamily Fossarinae Adams, 1860
                     1 Genus Megalomphalus Brusina, 1871
                     2 Genus Couthouyia A. Adams, 1860
                     3 Genus Fossarus Philippi, 1841
                     4 Genus Chilkaia Preston, 1915