[organisms] see Clade Biota Wagner 2004 [Wiemann, de Queiroz, Rowe, Planavsky, Anderson, Gogarten, Turner & Gauthier 2020]
   Phylum Mollusca Linnaeus, 1758 - molluscs
     Class Bivalvia Linnaeus, 1758 - bivalves
       01 Family Xenoturbellidae Westblad, 1949
       02 Family Solemyidae Gray, 1840 - awning clams
       03 Family Nuculidae Gray, 1824 - nut clams
       04 Family Pristiglomidae Sanders & Allen, 1973 see Subfamily Pristiglominae Sanders & Allen, 1973
       05 Family Nuculanidae Adams & Adams, 1858 (1854) - pointed nut clams
       06 Family Malletidae see Family Malletiidae Adams & Adams, 1858 (1846)
       07 Family Neilonellidae Schileyko, 1989
       08 Family Spinulidae Allen & Sanders, 1982 see Family Bathyspinulidae Coan & Valentich-Scott, 1997
       09 Family Tindariidae Verrill & Bush, 1897
       10 Family Yoldiidae Dall, 1908
       11 Family Arcidae Lamarck, 1809 - arks
       12 Family Noetiidae Stewart, 1930
       13 Family Limopsidae Dall, 1895
       14 Family Glycymerididae Dall, 1908 (1847) - glycymerids
       15 Family Mytilidae Rafinesque, 1815 - marine mussels
       16 Family Pinnidae Leach, 1819 - pen clams
       17 Family Pteriidae Gray, 1847 (1820) - winged oysters
       18 Family Malleidae Lamarck, 1818 - hammer oysters
       19 Family Isognomonidae Woodring, 1925 (1828)
       20 Family Pectinidae Rafinesque, 1815 - scallops
       21 Family Spondylidae Gray, 1826 - thorny oysters
       22 Family Anomiidae Rafinesque, 1815 - jingles
       23 Family Limidae Rafinesque, 1815 - file clams
       24 Family Ostreidae Rafinesque, 1815 - true oysters
       25 Family Gryphaeidae Vialov, 1936
       26 Family Lucinidae Fleming, 1828 - lucines
       27 Family Thyasiridae Dall, 1900 (1895)
       28 Family Ungulinidae Gray, 1854
       29 Family Chamidae Lamarck, 1809 - jewel boxes
       30 Family Galeommatidae Gray, 1840
       31 Family Kelliidae Forbes & Hanley, 1848 see Family Lasaeidae Gray, 1842
       32 Family Lasaeidae Gray, 1842
       33 Family Leptonidae Gray, 1847 see Family Lasaeidae Gray, 1842
       34 Family Montacutidae Clark, 1855 see Family Lasaeidae Gray, 1842
       35 Family Neoleptonidae Thiele, 1934
       36 Family Sportellidae Dall, 1899
       37 Family Turtoniidae Clark, 1855 see Subfamily Turtoniinae Clark, 1855
       38 Family Carditidae Férussac, 1822 - little heart shells
       39 Family Astartidae d'Orbigny, 1844 (1840) - astarte clams
       40 Family Crassatellidae Férussac, 1822
       41 Family Cardiidae Lamarck, 1809 - cockles
       42 Family Mactridae Lamarck, 1809 - surf clams
       43 Family Mesodesmatidae Gray, 1840
       44 Family Solenidae Lamarck, 1809 - razor clams
       45 Family Pharidae Adams & Adams, 1856
       46 Family Tellinidae Blainville, 1814 - tellinids
       47 Family Donacidae Fleming, 1828 - wedge shells
       48 Family Psammobiidae Fleming, 1828 - sunset clams
       49 Family Scrobiculariidae Adams & Adams, 1856 see Subfamily Scrobiculariinae Adams & Adams, 1856
       50 Family Semelidae Stoliczka, 1870 (1825) - semelids
       51 Family Solecurtidae d'Orbigny, 1846 - razor clams
       52 Family Arcticidae Newton, 1891 (1844)
       53 Family Kelliellidae Fischer, 1887
       54 Family Trapezidae Lamy, 1920 (1895), orth. cons.
       55 Family Vesicomyidae Dall & Simpson, 1901
       56 Family Glossidae Gray, 1847 (1840) - oxheart clams
       57 Family Veneridae Rafinesque, 1815 - venus clams
       58 Family Petricolidae d'Orbigny, 1840 - rock borers see Subfamily Petricolinae d'Orbigny, 1840
       59 Family Myidae Lamarck, 1809 - soft-shelled clams
       60 Family Corbulidae Lamarck, 1818
       61 Family Gastrochaenidae Gray, 1840 - rock borers
       62 Family Hiatellidae Gray, 1824 - geoducks
       63 Family Pholadidae Lamarck, 1809 - piddocks
       64 Family Teredinidae Rafinesque, 1815 - shipworms
       65 Family Xylophagidae Purchon, 1941, nom. illeg. see Family Xylophagaidae Purchon, 1941
       66 Family Pholadomyidae King, 1844
       67 Family Thraciidae Stoliczka, 1870 (1839)
       68 Family Laternulidae Hedley, 1918
       69 Family Periplomatidae Dall, 1895
       70 Family Clavagellidae d'Orbigny, 1844, nom. protect.
       71 Family Pandoridae Rafinesque, 1815
       72 Family Lyonsiidae Fischer, 1887
       73 Family Poromyidae Dall, 1886
       74 Family Verticordiidae Stoliczka, 1870
       75 Family Cuspidariidae Dall, 1886