| Adapidae(noun, creature, geohistory, appearance, eocene) |
| Adapiformes(noun, creature, geohistory, appearance, eocene) |
| Adapinae(noun, creature, geohistory, appearance, eocene) |
| Afrotarsius(noun, creature, geohistory, appearance, eocene) |
| Ambulocetidae(noun, creature, geohistory, appearance, eocene) |
| Amynodontidae(noun, creature, geohistory, appearance, eocene) |
| Anchitheriinae(noun, creature, geohistory, appearance, eocene) |
| Ancylopoda(noun, creature, geohistory, appearance, eocene) |
| Anoplotheriidae(noun, creature, geohistory, appearance, eocene) |
| Anthracotheriidae(noun, creature, geohistory, appearance, eocene) |
| Anthracotherium(noun, creature, geohistory, appearance, eocene) |
| Archaeohyrax(noun, creature, geohistory, appearance, eocene) |
| Archaeopithecidae(noun, creature, geohistory, appearance, eocene) |
| Archaeotherium(noun, creature, geohistory, appearance, eocene) |
| Arsinoitheriidae(noun, creature, geohistory, appearance, eocene) |
| Asiadapinae(noun, creature, geohistory, appearance, eocene) |
| Asterostomatidae(noun, creature, geohistory, appearance, eocene) |
| Astrapotheriidae(noun, creature, geohistory, appearance, eocene) |
| Azibiidae(noun, creature, geohistory, appearance, eocene) |
| Barytherium(noun, creature, geohistory, appearance, eocene) |