Stratigraphic time - taxa
genus Abies Mill. - fir (Hauterivian - recent)
subfamily Abietoideae Lindl. Emend Pilger & Melchior (Hauterivian - recent)
genus Abyssothyris Thomson, 1927 (Tertiary - recent)
infraorder Achelata Scholtz & Richter, 1995 (Lower Triassic - recent)
suborder Acipenseroidei (Upper Cretaceous - recent)
genus Acrobrochus Cooper, 1983 (Tertiary - recent)
superorder Actinistia (Middle Devonian - recent)
class Actinopterygii Klein, 1885 - ray-finned fishes (Upper Silurian - recent)
suborder Adephaga Schellenberg, 1806 (Hettangian - recent)
subfamily Aesalinae MacLeay, 1819 (Cenomanian - recent)
tribus Aesalini MacLeay, 1819 (Upper Cretaceous - recent)
family Agamidae Gray, 1827 - agamas (Upper Cretaceous - recent)
species Agonum antiquum Piton, 1940 (Selandian)
subfamily Agrypninae Candèze, 1857 (Cenomanian - recent)
genus Alavesia Waters & Arillo, 1999 (Cenomanian - recent)
subfamily Aleuropteryginae (Callovian - recent)
family Alligatoridae Gray, 1844 (Upper Cretaceous - recent)
order Ambystomatoidea (Upper Cretaceous - recent)
family Amiidae Bonaparte, 1831 - bowfins (Upper Jurassic - recent)
order Amiiformes Hay, 1929 - bowfins (Lower Triassic - recent)
subfamily Amnestinae Hart, 1919 (Aptian - recent)
kingdom Amoebozoa Lühe, 1913 emend. Cavalier-Smith, 1998 (Neoproterozoic - recent)
family Amorphoscelidae Stål, 1877 (Aptian - recent)
subfamily Amorphoscelinae Stål, 1877 (Aptian - recent)
tribus Amorphoscelini Stål, 1877 (Aptian - recent)
family Amphiumidae Garden in Smith, 1821 - amphiumas (Upper Cretaceous - recent)
order Amphiumoidea (Upper Cretaceous - recent)
subfamily Anaidinae Nikolajev, 1996 (Lower Cretaceous - recent)
family Anguidae Gray, 1825 - glass lizards (Upper Cretaceous - recent)
family Aniliidae Stejneger, 1907 - cylinder snakes (Cretaceous - recent)
suborder Anisoneura Lioy, 1864 (Upper Triassic - recent)
infraorder Anisopodomorpha Tuomikoski, 1961 (Upper Triassic - recent)
family Anthribidae Billberg, 1820 - fungus weevils (Middle Jurassic - recent)
suborder Apocrita Gerstäcker, 1867 (Berriasian - recent)
infraclass Apoda Oppel, 1810 (Lower Jurassic - recent)
family Aradidae Brullé, 1836 (Cenomanian - recent)
superfamily Aradoidea Brullé, 1836 (Cenomanian - recent)
family Araucariaceae Henkel & Hochst. (Oxfordian - recent)
family Arbaciidae Gray, 1855 (Lower Cretaceous - recent)
superorder Archosauria (Lopingian - recent)
cohors Archosauromorpha Huene, 1946 (Lopingian - recent)
suborder Archostemata Kolbe, 1908 (Upper Triassic - recent)
phylum Arthropoda Gravenhorst, 1843 - arthropods (Cambrian - recent)
genus Arvernineura Piton, 1940 (Paleocene)
species Arvernineura insignis Piton, 1940 (Paleocene)
family Asilidae Kirby & Spence, 1817 - robber flies (Cenomanian - recent)
superfamily Asiloidea (Cenomanian - recent)
infraorder Asilomorpha Rohdendorf, 1961 (Callovian - recent)
family Astacidae Latreille, 1802 - crayfishes (Upper Jurassic - recent)
infraorder Astacidea Latreille, 1802 (Lower Jurassic - recent)
superfamily Astacoidea Latreille, 1802 - Crayfishes (Upper Jurassic - recent)
class Asteroidea De Blainville, 1830 (Lower Ordovician - recent)
family Atelestidae Hennig, 1970 (Cenomanian - recent)
subfamily Atelestinae Hennig, 1970 (Cenomanian - recent)
subfamily Attageninae Laporte de Castelnau, 1840 (Cenomanian - recent)
tribus Attagenini Laporte de Castelnau, 1840 (Cenomanian - recent)
genus Attagenus Latreille, 1802 (Cenomanian - recent)
suborder Auchenorrhyncha Duméril, 1806 - cicadas and leafhoppers (Artinskian - recent)
class Aves Linnaeus, 1758 - birds (Upper Jurassic - recent)
species Belemnobatis variabilis Underwood & Rees, 2002 (Berriasian - recent)
family Belostomatidae Leach, 1815 - toe biters (Callovian - recent)
family Berothidae Handlirsch, 1906 - Beaded lacewings (Oxfordian - recent)
family Bethylidae Halliday, 1839 (Cenomanian - recent)
family Bibionidae Fleming, 1821 - march flies (Lower Cretaceous - recent)
superfamily Bibionoidea Fleming, 1821 (Lower Cretaceous - recent)
infraorder Bibionomorpha Hennig, 1954 (Berriasian - recent)
family Biphyllidae LeConte, 1861 - false skin beetles (Santonian - recent)
subfamily Bittacomorphinae (Hauterivian - recent)
family Blaberidae Brunner von Wattenwyl, 1865 - giant cockroaches (Cenomanian - recent)
superfamily Blaberoidea Brunner von Wattenwyl, 1865 (Cenomanian - recent)
subfamily Blaptinae Leach, 1815 (Middle Paleocene - recent)
family Blattidae Latreille, 1810 (Cenomanian - recent)
order Blattodea Latreille, 1810 - cockroaches (Cenomanian - recent)
superfamily Blattoidea Latreille, 1810 (Cenomanian - recent)
family Blephariceridae Schiner, 1862 - Net-winged midges (Callovian - recent)
superfamily Blephariceroidea Brues & Melander, 1932 (Callovian - recent)
infraorder Blephariceromorpha Rohdendorf, 1961 (Callovian - recent)
family Boidae Gray, 1825 - boas and pythons (Upper Cretaceous - recent)
subfamily Bolboceratinae Mulsant, 1842 (Lower Cretaceous - recent)
tribus Bolboceratini Mulsant, 1842 (Lower Cretaceous - recent)
family Bostrichidae Latreille, 1802 - branch-and-twig borers (Albian - recent)
infraorder Bostrichiformia Forbes, 1926 (Albian - recent)
superfamily Bostrichoidea Latreille, 1802 (Albian - recent)
phylum Brachiopoda Duméril, 1806 - lamp shells (Cambrian - recent)
suborder Brachycera Schiner, 1862 (Callovian - recent)
tribus Brachyglutini Raffray, 1904 (Cenomanian - recent)