Primate canines from the early Miocene Pinturas Formation, Southern Argentina

Previously undescribed canines from the Pinturas Formation (Santacrucian, early Miocene) in Patagonia, Argentina, indicate the presence of new primate taxa. These isolated teeth exhibit a generalized structure; the crowns are robust at the base, slightly or nonprojecting beyond the occlusal plane of the cheek teeth, with a relatively rounded or slightly sharp entocristid in the lowers. It is possible to distinguish at least one, possibly two, new primate genera. One taxon is slightly smaller than Soriacebus adrianae and morphologically distinct. The other may be an early relative of Alouatta, and if so it would expand the temporal and geographic range of this lineage. A third taxon is represented by an advanced pitheciin (? Soriacebus). Other isolated canines could be attributed to Carlocebus, but precise attribution remains uncertain. Despite the fragmentary nature of these specimens, and some unresolved taxonomic and phylogenetic questions, there is clear evidence for a greater diversity of fossil primates in Patagonia during the early Miocene than previously recognized.