| Oligopithecidae(noun, fauna, extinction, rupelian) |
| Oxytoma(noun, extinction, paleocene, genus) |
| Palaeocarpilius(noun, fauna, extinction, rupelian) |
| Pantodonta(noun, fauna, extinction, priabonian) |
| Paratylopus(noun, fauna, extinction, rupelian) |
| Parvitragulus(noun, fauna, extinction, priabonian) |
| Pentacosmodon(noun, extinction, paleocene, genus) |
| Phiomia(noun, fauna, extinction, rupelian) |
| Pleuraspidotherium(noun, extinction, paleocene, genus) |
| Poabromylus(noun, fauna, extinction, priabonian) |
| Poebrotherium(noun, fauna, extinction, rupelian) |
| Presbyornithidae(noun, fauna, extinction, rupelian) |
| Prionessus(noun, extinction, paleocene, genus) |
| Prodinoceras(noun, extinction, paleocene, genus) |
| Proplatyarthrus(noun, extinction, genus, oligocene) |
| Protitanotherium(noun, fauna, extinction, priabonian) |
| Pseudoprotoceras(noun, fauna, extinction, bartonian) |
| Psittacotherium(noun, extinction, paleocene, genus) |
| Purgatorius(noun, extinction, paleocene, genus) |
| Pycnodontidae(noun, fauna, extinction, lutetian) |