• Abditodentrix pseudothalmanni (Boltovskoy & Guissani de Kahn, 1981): Pliocene
• Abditodentrix pseudothalmanni (Boltovskoy & Guissani de Kahn, 1981): Miocene
• Abertella gualichensis Martínez, Reichler & Mooi, 2005 †: Miocene
• Abertella kewi Durham, 1957 †: Miocene
• Abertella palmeri Durham, 1957 †: Miocene
• Abra cytheraeformis Cossmann & Peyrot, 1909 †: Aquitanian
• Abra fragosa (Marwick, 1931) †: Miocene
• Abra inflata (Laws, 1939) †: Miocene
• Abra marshalli (H. J. Finlay, 1927) †: Miocene
• Acanthinula clairi Schlickum & Truc, 1972 †: Piacenzian
• Acanthinula hesslerana Jooss, 1911 †: Aquitanian
• Acanthocardia allae Studencka & Popov, 1996 †: Miocene
• Acanthocardia andreae (Dujardin, 1837) †: Miocene
• Acanthocardia bianconiana (Cocconi, 1873) †: Pliocene
• Acanthocardia leognanensis (Mayer, 1866) †: Burdigalian
• Acanthocardia otarii (Kharatishvili, 1952) †: Miocene
• Acanthocardia perrugosa (Fontannes, 1882) †: Pliocene
• Acanthocardia saucatsensis (Mayer, 1866) †: Burdigalian
• Acanthocardia subserrigera (A. d'Orbigny, 1852) †: Burdigalian
• Acanthocardia subserrigera (A. d'Orbigny, 1852) †: Aquitanian
• Acanthocardia turonica (M. Hörnes, 1861) †: Miocene
• Acanthocardia vidali (Cossmann & Peyrot, 1912) †: Miocene
• Acanthochitona andegavensis Dell'Angelo, Landau, Van Dingenen & Ceulemans, 2018 †: Tortonian
• Acanthochitona chauvereauensis Dell'Angelo, Landau, Van Dingenen & Ceulemans, 2018 †: Tortonian
• Acanthochitona flebilis (Laws, 1950) †: Pliocene
• Acanthochitona globosa Dell'Angelo, Landau, Van Dingenen & Ceulemans, 2018 †: Tortonian
• Acanthotrophon aturi (Deshayes, 1865) †: Burdigalian
• Acanthotrophon aturi (Deshayes, 1865) †: Aquitanian
• Acanthotrophon striatus (Gabb, 1873) †: Pliocene
• Acar harringtoni Laws, 1947 †: Miocene
• Acar opuraensis (Bartrum & A. W. B. Powell, 1928) †: Pliocene
• Acar powelli Laws, 1950 †: Pliocene
• Acasta fischeri Locard, 1877 †: Miocene
• Acasta muricata Seguenza, 1876 †: Pliocene
• Acasta schafferi de Alessandri, 1910 †: Miocene
• Acasta spongites (Poli, 1791): Pliocene
• Acasta undulata Darwin, 1854 †: Pliocene
• Acella lixianensis X.-G. Zhu, 1985 †: Neogene
• Acerinucleus incudiferus (Maplestone, 1902) †: Neogene
• Acesta imitata (Suter, 1917) †: Pliocene
• Acesta plioiberica Brunetti & Della Bella, 2024 †: Piacenzian
• Acharax burica (Olsson, 1942) †: Pliocene
• Acharax doderleini (Mayer, 1861) †: Neogene
• Acharax gigas (Kanno, 1960) †: Miocene
• Acharax muroensis (Natori, 1964) †: Aquitanian
• Acharax subquadrata (Foresti, 1879) †: Miocene
• Acharax subventricosta Krishtofovich, 1984 †: Neogene
• Acharax ventricosa (Conrad, 1849) †: Neogene
• Acharax yessoensis (Kanehara, 1937) †: Miocene
• Acharax yokosukensis Kanie & Kuramochi, 1995 †: Miocene
• Acicula crassistoma Stworzewicz & Sołtys, 1996 †: Langhian
• Acicula crassistoma Stworzewicz & Sołtys, 1996 †: Burdigalian
• Acicula giuntellii Harzhauser, Neubauer & Esu, 2015 †: Messinian
• Acicula kadolskyi Manganelli, Cianfanelli, Barbato & Benocci, 2014 †: Zanclean
• Acicula kadolskyi Manganelli, Cianfanelli, Barbato & Benocci, 2014 †: Messinian
• Acicula limbata Reuss, 1861 †: Burdigalian
• Acila antefultoni Slodkevich, 1967 †: Miocene
• Acila perfecta Slodkevich, 1967 †: Miocene
• Acirsa awamoaensis (P. Marshall & Murdoch, 1921) †: Miocene
• Acirsa cookiana (Dell, 1956): Pliocene
• Acirsa lanceolata (Brocchi, 1814) †: Tortonian
• Acirsa oamarutica (Suter, 1917) †: Miocene
• Acirsa prisca (Suter, 1917) †: Miocene
• Acirsa sceauxsensis Landau, Ceulemans & Van Dingenen, 2018 †: Tortonian
• Acirsa subnodulosa (P. A. Maxwell, 1988) †: Miocene
• Aclis ascaris (W. Turton, 1819): Tortonian
• Aclis aurisparva Bertolaso & Garilli, 2009 †: Pliocene
• Aclis bartolomeae Tabanelli, 1997 †: Piacenzian
• Aclis cellinii Chirli, 2009 †: Piacenzian
• Aclis minor (T. Brown, 1827): Piacenzian
• Aclis planostoma (F. W. Hutton, 1885) †: Pliocene
• Aclis scalaris G. Seguenza, 1876 †: Piacenzian
• Aclis talaverai Brunetti & Cresti, 2018: Piacenzian
• Acremodontina maxwelli B. A. Marshall, 1995 †: Miocene
• Acremodontina varicosa B. A. Marshall, 1995: Pliocene
• Acrilloscala geniculata (Brocchi, 1814) †: Pliocene
• Acroloxus anatolicus Schütt, 1984 †: Serravallian
• Acroloxus anatolicus Schütt, 1984 †: Langhian
• Acroloxus ucrainicus Gozhik & Prysjazhnjuk, 1978 †: Tortonian
• Acrosterigma delectabile (P. A. Maxwell, 1978) †: Miocene
• Acrosterigma fraternum (Mayer, 1864) †: Burdigalian
• Acrosterigma fraternum (Mayer, 1864) †: Aquitanian
• Acrosterigma praecygnorum (Ludbrook, 1955) †: Pliocene
• Actapericulum bicarinatum Holmes, 1995 †: Langhian
• Actapericulum bicarinatum Holmes, 1995 †: Burdigalian
• Acteocina kirkwoodiana H. G. Richards & Harbison, 1944 †: Miocene
• Acteocina lajonkaireana (Basterot, 1825) †: Zanclean
• Acteocina pseudourupensis (V. P. Kolesnikov, 1935) †: Tortonian
• Acteocina puruha Pilsbry & Olsson, 1941 †: Pliocene
• Acteon articulatus Marwick, 1931 †: Miocene
• Acteon aubrechti Harzhauser, 2014 †: Burdigalian
• Acteon chilensis R. A. Philippi, 1887 †: Burdigalian
• Acteon glans H. C. Lea, 1845 †: Neogene
• Acteon infulatus Marwick, 1931 †: Miocene
• Acteon nitens I. Lea, 1846 †: Neogene
• Acteon novellus Conrad, 1834 †: Neogene
• Acteon oneroaensis A. W. B. Powell & Bartrum, 1929 †: Miocene
• Acteon otamateaensis Laws, 1941 †: Miocene
• Acteon semistriatus (Basterot, 1825) †: Zanclean
• Actinobalanus actinomorphus (Moroni, 1952) †: Pliocene