| Chattian first appearance(expression, geohistory, appearance, period, oligocene) |
| Extant Chattian first appearance(expression, geohistory, geogistory, period, oligocene) |
| paleogene first appearance(expression, appearance, period, oligocene) |
| Extant Oligocene first appearance(expression, geohistory, appearance, period, oligocene) |
| eocene first appearance(expression, geohistory, period, oligocene) |
| extant paleogene first appearance(expression, geohistory, period, oligocene) |
| Acanthochitona(noun, creature, geogistory, oligocene) |
| Acer smileyi(expression, creature, geohistory, chattian) |
| Aeluroidea(noun, creature, geogistory, oligocene) |
| Albatross(noun, creature, geogistory, oligocene) |
| Alligator(noun, creature, geogistory, oligocene) |
| Ameiurus(noun, creature, geogistory, oligocene) |
| Anatidae(noun, creature, geohistory, rupelian) |
| Aplodontiidae(noun, creature, geogistory, oligocene) |
| Archaeohippus(noun, creature, geohistory, chattian) |
| Balbaridae(noun, creature, geohistory, chattian) |
| Basking shark(expression, creature, geohistory, rupelian) |
| Batrachoididae(noun, creature, geohistory, rupelian) |
| Buccella(noun, creature, geogistory, oligocene) |
| Buccinum undatum(expression, creature, geohistory, rupelian) |