| Adapiformes(noun, creature, geohistory, eocene) |
| Adapinae(noun, creature, geohistory, eocene) |
| Afossochiton(noun, creature, geohistory, oligocene) |
| Afrotarsius(noun, creature, geohistory, eocene) |
| Ailuridae(noun, creature, geohistory, oligocene) |
| Ambulocetidae(noun, creature, geohistory, eocene) |
| Amphechinus(noun, creature, geohistory, oligocene) |
| Amynodontidae(noun, creature, geohistory, eocene) |
| Anchitheriinae(noun, creature, geohistory, eocene) |
| Ancylopoda(noun, creature, geohistory, eocene) |
| Andrias scheuchzeri(expression, creature, geohistory, oligocene) |
| Anoplotheriidae(noun, creature, geohistory, eocene) |
| Anthracotheriidae(noun, creature, geohistory, eocene) |
| Anthracotherium(noun, creature, geohistory, eocene) |
| Archaeohyrax(noun, creature, geohistory, eocene) |
| Archaeopithecidae(noun, creature, geohistory, eocene) |
| Archaeotherium(noun, creature, geohistory, eocene) |
| Archaeus(noun, creature, geohistory, thanetian) |
| Arsinoitheriidae(noun, creature, geohistory, eocene) |
| Asiadapinae(noun, creature, geohistory, eocene) |