A new species ofPurgatorius(Mammalia; Primatomorpha) from the Lower Paleocene Bear Formation, Crazy Mountains Basin, south-central Montana

Purgatorius titusi,represented by 51 teeth and jaw fragments, is described from the lower Paleocene Bear Formation of the Crazy Mountains Basin in south-central Montana. Several synapomorphies, including a weak postprotocingulum and mesial inflection of molar trigonids, are indicative of the taxon's “plesiadapiform” affinities. Other features, such as wider stylar shelf and a less squared lingual outline on upper molars, are more primitive than those ofPurgatorius unio,heretofore the earliest occurring species of well-represented primatomorphs.