Aachenaspis Egerton, 1857 † accepted as Auchenaspis Egerton, 1857 † (basis of record)
Aachenaspis Egerton, 1857 † accepted as Auchenaspis Egerton, 1857 † (extant flag source)
Aachenaspis Egerton, 1857 † accepted as Auchenaspis Egerton, 1857 † (habitat flag source)
Aacocrinus Bowsher, 1955 † (basis of record)
Aacocrinus Bowsher, 1955 † (current name source)
Aacocrinus Bowsher, 1955 † (extant flag source)
Aacocrinus Bowsher, 1955 † (habitat flag source)
Aaglacrinus † accepted as Aglaocrinus Strimple, 1961 † (basis of record)
Aaglacrinus † accepted as Aglaocrinus Strimple, 1961 † (extant flag source)
Aaglacrinus † accepted as Aglaocrinus Strimple, 1961 † (habitat flag source)
Aaleniella Conti & Fischer, 1981 † (basis of record)
Aaleniella Conti & Fischer, 1981 † (current name source)
Aaleniella Conti & Fischer, 1981 † (extant flag source)
Aaleniella Conti & Fischer, 1981 † (habitat flag source)
Aaleniella Plumhoff, 1963 † (basis of record)
Aaleniella Plumhoff, 1963 † (current name source)
Aaleniella Plumhoff, 1963 † (extant flag source)
Aaleniella Plumhoff, 1963 † (habitat flag source)
Aalenirhynchia Shi & Grant, 1993 † (basis of record)
Aalenirhynchia Shi & Grant, 1993 † (current name source)
Aalenirhynchia Shi & Grant, 1993 † (extant flag source)
Aalenirhynchia Shi & Grant, 1993 † (habitat flag source)
Aatocrinus Moore & Plummer, 1940 † (basis of record)
Aatocrinus Moore & Plummer, 1940 † (current name source)
Aatocrinus Moore & Plummer, 1940 † (extant flag source)
Aatocrinus Moore & Plummer, 1940 † (habitat flag source)
Abacocrinus Angelin, 1878 † (basis of record)
Abacocrinus Angelin, 1878 † (current name source)
Abacocrinus Angelin, 1878 † (extant flag source)
Abacocrinus Angelin, 1878 † (habitat flag source)
Abactinocrinus Laudon & Severson, 1953 † (basis of record)
Abactinocrinus Laudon & Severson, 1953 † (current name source)
Abactinocrinus Laudon & Severson, 1953 † (extant flag source)
Abactinocrinus Laudon & Severson, 1953 † (habitat flag source)
Abadehella Okimura & Ishii in Okimura, Ishii & Nakazawa, 1975 † (basis of record)
Abadehella Okimura & Ishii in Okimura, Ishii & Nakazawa, 1975 † (current name source)
Abadehella Okimura & Ishii in Okimura, Ishii & Nakazawa, 1975 † (extant flag source)
Abadehella Okimura & Ishii in Okimura, Ishii & Nakazawa, 1975 † (habitat flag source)
Abadzekhia Bannikov, 1985 † (basis of record)
Abadzekhia Bannikov, 1985 † (current name source)
Abadzekhia Bannikov, 1985 † (extant flag source)
Abadzekhia Bannikov, 1985 † (habitat flag source)
Abakania Poletaeva, 1973 † (basis of record)
Abakania Poletaeva, 1973 † (current name source)
Abakania Poletaeva, 1973 † (habitat flag source)
Abakanopleura Sivov in Khalfin, 1955 † (basis of record)
Abakanopleura Sivov in Khalfin, 1955 † (current name source)
Abakanopleura Sivov in Khalfin, 1955 † (habitat flag source)
Abathocrinus Strimple, 1963 † (basis of record)
Abathocrinus Strimple, 1963 † (current name source)
Abathocrinus Strimple, 1963 † (extant flag source)
Abathocrinus Strimple, 1963 † (habitat flag source)
Abathomphalus Bolli, Loeblich & Tappan, 1957 † (basis of record)
Abathomphalus Bolli, Loeblich & Tappan, 1957 † (current name source)
Abathomphalus Bolli, Loeblich & Tappan, 1957 † (extant flag source)
Abathomphalus Bolli, Loeblich & Tappan, 1957 † (habitat flag source)
Abatocrinus Lane, 1963 † (basis of record)
Abatocrinus Lane, 1963 † (current name source)
Abatocrinus Lane, 1963 † (extant flag source)
Abatocrinus Lane, 1963 † (habitat flag source)
Abatus Troschel, 1851 (extant flag source)
Abbasites Buckman, 1921 † (basis of record)
Abbasites Buckman, 1921 † (current name source)
Abbasites Buckman, 1921 † (extant flag source)
Abbasites Buckman, 1921 † (habitat flag source)
Abderospira Dall, 1896 † accepted as Roxania Leach in Gray, 1847 (basis of record)
Abderospira Dall, 1896 † accepted as Roxania Leach in Gray, 1847 (extant flag source)
Abderospira Dall, 1896 † accepted as Roxania Leach in Gray, 1847 (habitat flag source)
Abditodentrix Patterson, 1985 (extant flag source)
Abditoloculina Kesling, 1952 † (basis of record)
Abditoloculina Kesling, 1952 † (current name source)
Abditoloculina Kesling, 1952 † (extant flag source)
Abditoloculina Kesling, 1952 † (habitat flag source)
Abdounia Cappetta, 1980 † (basis of record)
Abdounia Cappetta, 1980 † (current name source)
Abdounia Cappetta, 1980 † (extant flag source)
Abdounia Cappetta, 1980 † (habitat flag source)
Abdulinaspis Ergaliev, 1980 † (basis of record)
Abdulinaspis Ergaliev, 1980 † (current name source)
Abdulinaspis Ergaliev, 1980 † (habitat flag source)
Abdullaevia Suleymanov, 1965 † (basis of record)
Abdullaevia Suleymanov, 1965 † (current name source)
Abdullaevia Suleymanov, 1965 † (extant flag source)
Abdullaevia Suleymanov, 1965 † (habitat flag source)
Aberia Melou, 1990 † (basis of record)
Aberia Melou, 1990 † (current name source)
Aberia Melou, 1990 † (extant flag source)
Aberia Melou, 1990 † (habitat flag source)
Abertella Durham, 1953 † (basis of record)
Abertella Durham, 1953 † (current name source)
Abertella Durham, 1953 † (extant flag source)
Abertella Durham, 1953 † (habitat flag source)
Abharella Wittke, 1984 † (basis of record)
Abharella Wittke, 1984 † (current name source)
Abharella Wittke, 1984 † (habitat flag source)
Abichites Shevyrev, 1965 † (basis of record)
Abichites Shevyrev, 1965 † (current name source)
Abichites Shevyrev, 1965 † (extant flag source)
Abichites Shevyrev, 1965 † (habitat flag source)
Abicyathus Jankauskas, 1972 † (basis of record)

 Descriptive info

 for Terebellum Bruguière, 1798

Marine, extant (?) + fossil: Tertiary to Recent (Sepkoski 2002) [details]

 Descriptive info

 for Trimerella Billings, 1862 †

Marine, fossil: Silurian (Sepkoski 2002) [details]