| Archaeotherium(noun, creature, geohistory, eocene) |
| Arctostylopida(noun, creature, geohistory, paleocene) |
| Arsinoitheriidae(noun, creature, geohistory, eocene) |
| Asiadapinae(noun, creature, geohistory, eocene) |
| Asterostomatidae(noun, creature, geohistory, eocene) |
| Astrapotheria(noun, creature, geohistory, paleocene) |
| Astrapotheriidae(noun, creature, geohistory, eocene) |
| Aturia(noun, creature, geohistory, paleocene) |
| Azibiidae(noun, creature, geohistory, eocene) |
| Balbaridae(noun, creature, geohistory, chattian) |
| Barytherium(noun, creature, geohistory, eocene) |
| Basilosaurinae(noun, creature, geohistory, eocene) |
| Bear dog(expression, creature, geohistory, eocene) |
| Behemotops(noun, creature, geohistory, rupelian) |
| Bemalambdidae(noun, creature, geohistory, paleocene) |
| Borhyaenidae(noun, creature, geohistory, eocene) |
| Bothriogenys(noun, creature, geohistory, eocene) |
| Brontotheriidae(noun, creature, geohistory, eocene) |
| Buccella(noun, creature, eocene, geogistory) |
| Buteo(noun, creature, eocene, geogistory) |