Abyssorhynchia Zezina, 1980 (name verified source)
Abyssorhynchia Zezina, 1980 (basis of record)
Acanthaphritis Günther, 1880 (verified source for family)
Acanthohamingia Ikeda, 1910 (name verified source)
Acanthohamingia Ikeda, 1910 (basis of record)
Acanthopsaron Fricke, 2024 (verified source for family)
Acanthotheca Vendrasco, Kouchinsky, Porter & Fernandez, 2011 † (verified source for family)
Acropomatidae Gill, 1893 (taxonomy source)
Acropomatiformes (basis of record)
Actinoposthiidae Hooge, 2001 (basis of record)
Acutocoxae Rauschert, 2017 (additional source)
Adeorbella Briart & Cornet, 1887 † (current name source)
Adeorbella Briart & Cornet, 1887 † (verified source for family)
Agilestia Friend, 1982 (verified source for family)
Agnesia Michaelsen, 1898 accepted as Agnezia C. Monniot & F. Monniot, 1991 (source of synonymy)
Ainigma Helfer, 1938 accepted as Ascorhynchus Sars, 1878 (verified source for family)
Aktschagylia Starobogatov, 1970 (verified source for family)
Aktschagylia Starobogatov, 1970 (current name source)
Albidiator Lowry & Myers, 2019 (verified source for family)
Alexlutheria Karling, 1956 (verified source for family)
Alienella Starobogatov & Zatravkin, 1985 accepted as Sibirovalvata Starobogatov & Streletzkaja, 1967 (source of synonymy)
Alienella Starobogatov & Zatravkin, 1985 accepted as Sibirovalvata Starobogatov & Streletzkaja, 1967 (basis of record)
Alluroteuthidae accepted as Neoteuthidae Naef, 1921 (source of synonymy)
Altadema Kues, 2002 † (verified source for family)
Amekicarcinus Schweitzer, Odumodu & Feldmann, 2016 † (verified source for family)
Amniciana Servain, 1888 accepted as Pisidium C. Pfeiffer, 1821 (source of synonymy)
Amnigenia Hall, 1885 † (verified source for family)
Amnigenia Hall, 1885 † (current name source)
Amnigeniidae Khalfin, 1948 † (current name source)
Amnigeniidae Khalfin, 1948 † (taxonomy source)
Ampezzania Allasinaz in Allasinaz & Zardini, 1977 † (verified source for family)
Ampezzania Allasinaz in Allasinaz & Zardini, 1977 † (current name source)
Ampezzania Allasinaz in Allasinaz & Zardini, 1977 † (basis of record)
Amphisopidae Nicholls, 1943 (habitat flag source)
Amurohenslowiana Korniushin, 1996 accepted as Henslowiana Fagot, 1892 (basis of record)
Amurohenslowiana Korniushin, 1996 accepted as Henslowiana Fagot, 1892 (source of synonymy)
Anaucella Pchelintseva, 1955 † accepted as Buchia Rouillier, 1845 † (basis of record)
Anaucella Pchelintseva, 1955 † accepted as Buchia Rouillier, 1845 † (source of synonymy)
Ancistrocheiridae Pfeffer, 1912 (taxonomy source)
Angulomphalus Gründel, 2011 † (basis of record)
Angystoma Schumacher, 1817 accepted as Ringicella Gray, 1847 (source of synonymy)
Angystoma Schumacher, 1817 accepted as Ringicella Gray, 1847 (verified source for family)
Anisopsis Zilch, 1959 † accepted as Liangulorbis Wenz, 1947 † (source of synonymy)
Anisopsis Zilch, 1959 † accepted as Liangulorbis Wenz, 1947 † (basis of record)
Anostoma Fischer, 1807 (verified source for family)
Anostomopsidae Nordsieck, 1986 † (basis of record)
Anostomopsis Sandberger, 1871 (verified source for family)
Archanodon Howse, 1878 † (verified source for family)
Archanodon Howse, 1878 † (current name source)
Archinacellopsis Horný, 1995 † (current name source)
Architeuthidae Pfeffer, 1900 (taxonomy source)
Arcitalitrus Hurley, 1975 (verified source for family)
Argeneuthria Pastorino, 2016 (verified source for family)
Armenocerithium Egoyan, 1955 † (verified source for family)
Armenocerithium Egoyan, 1955 † (current name source)
Arribazona Kues, 1990 † (verified source for family)
Ascopariidae Sterrer, 1998 (basis of record)
Ascorhynchidae Hoek, 1881 (basis of record)
Asperosculptura Ardovini, Poppe & Tagaro, 2021 (basis of record)
Asterocyclina Gümbel, 1870 † (verified source for family)
Asthenodonta Whiteaves, 1894 † (current name source)
Asthenodonta Whiteaves, 1894 † (verified source for family)
Astrosphaeridae Haeckel, 1881 † (habitat flag source)
Aulacolambrus Paul'son, 1875 (habitat flag source)
Aulacophaedusa Habe, 1958 accepted as Megalophaedusa Böttger, 1877 (source of synonymy)
Auricullina Vassiljeva, 1998 (basis of record)
Auricullina Vassiljeva, 1998 (current name source)
Auricullina Vassiljeva, 1998 (verified source for family)
Australaraea Rowlett, 2020 accepted as Coscinaraea Milne Edwards & Haime, 1848 (verified source for family)
Australaraea Rowlett, 2020 accepted as Coscinaraea Milne Edwards & Haime, 1848 (source of synonymy)
Australopsammia Rowlett, 2020 accepted as Tubastraea Lesson, 1829 (source of synonymy)
Australopsammia Rowlett, 2020 accepted as Tubastraea Lesson, 1829 (verified source for family)
Austrotroides Friend, 1982 (verified source for family)
Axiola Luther, 1955 (verified source for family)
Azadinium Elbrächter & Tillmann, 2009 (extant flag source)
Azadinium Elbrächter & Tillmann, 2009 (habitat flag source)
Baikalomonotis Bychkov, 2007 † (basis of record)
Baikalomonotis Bychkov, 2007 † (current name source)
Baikalomonotis Bychkov, 2007 † (verified source for family)
Balcomitra Finlay, 1927 accepted as Austromitra Finlay, 1926 (source of synonymy)
Balcomitra Finlay, 1927 accepted as Austromitra Finlay, 1926 (basis of record)
Banjosidae Jordan & THompson, 1912 (taxonomy source)
Barana Dohrn, 1881 accepted as Ascorhynchus Sars, 1878 (verified source for family)
Bathyalozoidae d'Hondt, 1975 (basis of record)
Bathyclupeidae Gill, 1896 (taxonomy source)
Bathypallenopsis Stock, 1975 (verified source for family)
Bathyteuthidae Pfeffer, 1900 (taxonomy source)
Batoteuthidae Young & Roper, 1968 (taxonomy source)
Beauchampiola Luther, 1957 (verified source for family)
Bemellina Vassiljeva, 1998 † accepted as Igorella Missarzhevsky, 1969 † (basis of record)
Bemellina Vassiljeva, 1998 † accepted as Igorella Missarzhevsky, 1969 † (source of synonymy)
Benigoma Kuroda, 1928 accepted as Diplommatina Benson, 1849 (basis of record)
Benigoma Kuroda, 1928 accepted as Diplommatina Benson, 1849 (verified source for family)
Benigoma Kuroda, 1928 accepted as Diplommatina Benson, 1849 (source of synonymy)
Biotocus Salgado & Leme, 1990 (verified source for family)
Biplicatum Ouyang, Gan, Wu & Xu, 2010 (basis of record)
Biplicatum Ouyang, Gan, Wu & Xu, 2010 (verified source for family)
Biplicatum Ouyang, Gan, Wu & Xu, 2010 (current name source)
Bithloa Petuch & Drolshagen, 2011 † accepted as Pseudadusta Petuch, 2003 † accepted as Siphocypraea Heilprin, 1886 † (basis of record)
Bithloa Petuch & Drolshagen, 2011 † accepted as Pseudadusta Petuch, 2003 † accepted as Siphocypraea Heilprin, 1886 † (source of synonymy)

 Taxonomic remark

 for Aktschagylia Starobogatov, 1970

replacement name for Mactra Ali-Zade, 1967 (nec Linnaeus, 1767) [details]

 Taxonomic remark

 for Scolodens Baker, 1956

replacement name for Stenopus Guilding, 1828 (nec Latreille, 1819)  [details]