New specimens of Picromomyids (Plesiadapiformes, Primates) with description of a new species of Alveojunctus

Two new specimens attributable to the plesiadapiform family Picromomyidae are documented. One, a lower molar, represents a new species here named Alveojunctus bowni. This species is the largest and most derived picromomyid currently known, with an extremely simplified molar morphology. The second new specimen is a fragmentary lower jaw attributed to Picromomys petersonorum; the specimen includes the first complete lower central incisor known for a picromomyid. This tooth shows none of the derived features seen in microsyopid I₁s, providing no support for a tie to this family. Instead, it is most similar to I₁ in Tinimomys graybulliensis, supporting a close relationship between Picromomyidae and Micromomyidae.