Aix sponsa
Anatidae
Alabamasauripus aldrichi
Alaba opiniosa
Litiopidae
Alahexapus martini
Hexapodidae
Alasmidonta atropurpurea
Unionidae
Alasmidonta marginata
Unionidae
Alasmidonta raveneliana
Unionidae
Alasmidonta viridis
Unionidae
Alathyria jacksoni
Hyriidae
Alathyria pertexta
Hyriidae
Alathyria profuga
Hyriidae
Albula dunklei
Albulidae
Albulidarum ensis
Albulidae
Albunea gibbesii
Albuneidae
Albunea paretii
Albuneidae
Alectrion waltonensis
Nassariidae
Alethopteris valida
Medullosaceae
Allepithema pyramidatum
Assimineidae
Alligator mississippiensis
Alligatoridae
Allothyone mexicana
Phyllophoridae