Acanthaspidiidae Menzies, 1962 (additional source)
Acartiidae Sars G.O., 1903 (additional source)
Acrothoracica (additional source)
Adenopleurellidae Huys, 1990 (additional source)
Aegisthidae Giesbrecht, 1893 (additional source)
Aetideidae Giesbrecht, 1892-1893 (additional source)
Akentrogonida accepted as Rhizocephala (basis of record)
Albuneidae Stimpson, 1858 (additional source)
Alpheidae Rafinesque, 1815 (additional source)
Alpheoidea Rafinesque, 1815 (additional source)
Alvinocarididae Christoffersen, 1986 (additional source)
Amathillopsidae Pirlot, 1934 (additional source)
Ambunguipedidae Huys, 1990 accepted as Hamondiidae Huys, 1990 (additional source)
Ameiridae Boeck, 1865 (additional source)
Ampeliscidae Krøyer, 1842 (additional source)
Amphilochidae Boeck, 1871 (additional source)
Amphionidacea accepted as Caridea (additional source)
Amphionididae Holthuis, 1955 accepted as Pandalidae Haworth, 1825 (additional source)
Amphipoda (additional source)
Ampithoidae Boeck, 1871 (additional source)
Ancorabolidae Sars G.O., 1909 (additional source)
Anelasmatidae Gruvel, 1905 accepted as Pollicipedidae Leach, 1817 (additional source)
Anisogammaridae Bousfield, 1977 (additional source)
Anomoclausiidae Gotto, 1964 (additional source)
Anomopoda (basis of record)
Anomura (additional source)
Anostraca (basis of record)
Antheacheridae Sars M., 1870 (additional source)
Antheluridae Poore & Lew Ton, 1988 (additional source)
Anthessiidae Humes, 1986 (additional source)
Anthuridae Leach, 1814 (additional source)
Anthuridea accepted as Anthuroidea Leach, 1814 (additional source)
Aoridae Stebbing, 1899 (additional source)
Apygophora accepted as Lithoglyptida (additional source)
Archaeobalanidae Newman & Ross, 1976 accepted as Archaeobalaninae Newman & Ross, 1976 (additional source)
Arcturidae Dana, 1849 (additional source)
Argestidae Por, 1986 (additional source)
Argulidae Leach, 1819 (additional source)
Arguloidea Yamaguti, 1963 accepted as Arguloida (additional source)
Arietellidae Sars G.O., 1902 (additional source)
Aristeidae Wood-Mason in Wood-Mason & Alcock, 1891 (additional source)
Armadillidiidae Brandt, 1833 (additional source)
Armadilloidea Brandt in Brandt & Ratzeburg, 1831 accepted as Armadillidae Brandt in Brandt & Ratzeburg, 1831 (basis of record)
Artotrogidae Brady, 1880 (additional source)
Ascidicolidae Thorell, 1859 (additional source)
Asconiscidae Bonnier, 1900 (additional source)
Ascothoracida (additional source)
Ascothoracidae Grygier, 1987 (additional source)
Aselloidea Latreille, 1802 (basis of record)
Asellota (additional source)
Astacidea (additional source)
Astacoidea Latreille, 1802 (taxonomy source)
Asterocheridae Giesbrecht, 1899 (additional source)
Atelecyclidae Ortmann, 1893 (additional source)
Atyidae De Haan, 1849 (additional source)
Atyoidea De Haan, 1849 (additional source)
Augaptilidae Sars G.O., 1905 (additional source)
Axiidae Huxley, 1879 (additional source)
Axioidea Huxley, 1879 accepted as Axiidea (additional source)
Balaenophilidae Sars G.O., 1910 (additional source)
Balanoidea Leach, 1817 (additional source)
Balanomorpha (additional source)
Basipodellidae Boxshall & Lincoln, 1983 (additional source)
Bathylasmatidae Newman & Ross, 1971 (additional source)
Bathypalaemonellidae de Saint Laurent, 1985 (additional source)
Bathypontiidae Brodsky, 1950 (additional source)
Benthesicymidae Wood-Mason in Wood-Mason & Alcock, 1891 (additional source)
Bentheuphausiidae Colosi, 1917 (additional source)
Biancolinidae J.L. Barnard, 1972 accepted as Ampithoidae Boeck, 1871 (additional source)
Bodotriidae T. Scott, 1901 (additional source)
Bogidiellidae Hertzog, 1936 (additional source)
Bomolochidae Claus, 1875 (additional source)
Bopyridae Rafinesque, 1815 (additional source)
Bopyroidea Rafinesque, 1815 (basis of record)
Bosminidae Baird, 1845 (basis of record)
Branchiopoda (taxonomy source)
Branchiura (additional source)
Bresiliidae Calman, 1896 (additional source)
Bresilioidea Calman, 1896 (additional source)
Brychiopontiidae Humes, 1974 (additional source)
Buproridae Thorell, 1859 (additional source)
Bythograeidae Williams, 1980 (additional source)
Bythograeoidea Williams, 1980 (additional source)
Calanoida (additional source)
Calanticidae Zevina, 1978 (additional source)
Calappidae De Haan, 1833 (additional source)
Calappoidea De Haan, 1833 (additional source)
Caligidae Burmeister, 1835 (additional source)
Callianassidae Dana, 1852 (additional source)
Callianassoidea Dana, 1852 accepted as Callianassidae Dana, 1852 (additional source)
Calocarididae Ortmann, 1891 accepted as Axiidae Huxley, 1879 (additional source)
Calverocheridae Stock, 1968 (additional source)
Campylonotoidea Sollaud, 1913 (additional source)
Cancerillidae Giesbrecht, 1897 (additional source)
Cancroidea Latreille, 1802 (additional source)
Candaciidae Giesbrecht, 1892-1893 (additional source)
Canthocamptidae Brady, 1880 (additional source)
Caprellidae Leach, 1814 (additional source)
Caprellidea accepted as Caprelloidea Leach, 1814 (basis of record)
Carangoliopsidae Bousfield, 1977 (additional source)