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 Bivalvia Linnaeus, 1758 - bivalves
             1 Subclass Protobranchia Pelseneer, 1889
             2 Subclass Pteriomorphia Beurlen, 1944 see Superorder Pteriomorphia Beurlen, 1944
             3 Subclass Palaeoheterodonta Newell, 1965 see Clade Palaeoheterodonta Newell, 1965
             3 Subclass Paleoheterodonta see Order Unionida Gray, 1854
             4 Subclass Heterodonta Neumayr, 1884 see Clade Heterodonta Neumayr, 1884
             5 Subclass Anomalodesmata Dall, 1889 see Order Anomalodesmata Dall, 1889