| Idrissia(noun, fauna, eocene, extinction) |
| Isocrania(noun, fauna, extinction, paleocene) |
| Jiangxia(noun, fauna, extinction, paleocene) |
| Kankatodus(noun, fauna, extinction, paleocene) |
| Kimbetohia(noun, fauna, extinction, paleocene) |
| Kingena(noun, fauna, extinction, paleocene) |
| Kogaionidae(noun, fauna, extinction, paleocene) |
| Krauseia(noun, fauna, extinction, paleocene) |
| Lambdopsalidae(noun, fauna, eocene, extinction) |
| Lambdopsalis(noun, fauna, extinction, paleocene) |
| Lammidhania(noun, fauna, eocene, extinction) |
| Leptauchenia(noun, fauna, extinction, oligocene) |
| Leptictida(noun, fauna, extinction, oligocene) |
| Linthia(noun, fauna, eocene, extinction) |
| Liotomus(noun, fauna, extinction, paleocene) |
| Lopez de Bertodano Formation(expression, geohistory, formation, paleogene) |
| Lutetian extinction(expression, extinction, period, geochronology) |
| Macginitiea(noun, fauna, eocene, extinction) |
| Machaeroides(noun, fauna, eocene, extinction) |
| Madtsoiidae(expression, fauna, extinction, paleogene) |