| Oreodontoides(noun, creature, geohistory, chattian) |
| Ornithorhynchidae(noun, creature, geohistory, paleocene) |
| Osbornodon(noun, creature, geohistory, rupelian) |
| Osbornodon iamonensis(expression, creature, geohistory, rupelian) |
| Owl(noun, creature, geohistory, paleocene) |
| Oxydactylus(noun, creature, geohistory, chattian) |
| Pacific giant salamander(expression, creature, geohistory, paleocene) |
| Paenungulata(noun, creature, geohistory, paleocene) |
| Palaelodidae(noun, creature, geohistory, rupelian) |
| Palimphyes(noun, creature, geohistory, thanetian) |
| Palorchestidae(noun, creature, geohistory, chattian) |
| Pangolin(noun, creature, geohistory, paleocene) |
| Paraceratherium(noun, creature, geohistory, rupelian) |
| Paradaphoenus(noun, creature, geohistory, rupelian) |
| Paraenhydrocyon(noun, creature, geohistory, rupelian) |
| Paraenhydrocyon josephi(expression, creature, geohistory, rupelian) |
| Pelagornis(noun, creature, geohistory, chattian) |
| Pelagornithidae(noun, creature, geohistory, thanetian) |
| Phenacocoelus(noun, creature, geohistory, chattian) |
| Phidoloporidae(noun, creature, geohistory, paleocene) |