| Oldfieldthomasiidae(noun, fauna, eocene, extinction) |
| Oromerycidae(noun, fauna, eocene, extinction) |
| Pakicetidae(noun, fauna, eocene, extinction) |
| Palaeoamasiidae(noun, fauna, eocene, extinction) |
| Palaeochiropterygidae(noun, fauna, eocene, extinction) |
| Palaeophiidae(noun, fauna, eocene, extinction) |
| Phenacodontidae(noun, fauna, eocene, extinction) |
| Plesiadapiformes(noun, fauna, eocene, extinction) |
| Priscagamidae(noun, fauna, eocene, extinction) |
| Pristichampsidae(noun, fauna, eocene, extinction) |
| Prorastomidae(noun, fauna, eocene, extinction) |
| Protocetidae(noun, fauna, eocene, extinction) |
| Pteridospermatophyta(noun, fauna, eocene, extinction) |
| Ptilodontoidea(noun, fauna, eocene, extinction) |
| Raoellidae(noun, fauna, eocene, extinction) |
| Remingtonocetidae(noun, fauna, eocene, extinction) |
| Sclerorhynchidae(noun, fauna, eocene, extinction) |
| Simimyidae(noun, fauna, eocene, extinction) |
| Sophiornithidae(noun, fauna, eocene, extinction) |
| Tillodontia(noun, fauna, eocene, extinction) |