Branisella

Branisella is an extinct genus of New World monkey from the Salla Formation of what is now Bolivia during the Late Oligocene, approximately 26 million years ago (Deseadan), comprising only the species Branisella boliviana. Together with the Peruvian genus "Canaanimico", it is the oldest fossil New World monkey discovered.
Description.
It was found in Bolivia by the paleontologist Leonardo Branisa, and it was named after him by Hoffstetter, the scientist who first described and classified it in 1969. Morphologically, it is similar to "Proteopithecus", an Oligocene primate from Africa, in its reduced upper second premolar and unreduced lower second premolar. This suggests the primitive platyrrhine ancestors of "Branisella" came to South America from Africa. Other features, however, suggest that it may have been related to the omomyids, an extinct group of tarsier-like primates found in North America, among other places.
Within platyrrhines, this taxon has been interpreted as either a stem platyrrhine not related to any of the living forms, or as a primitive callitrichine. As "Branisella" is currently the only South American primate taxon known until the Miocene, more fossils are needed before its phylogenetic position can be clearly established.
The cheek teeth of "Branisella" are very high-crowned, suggesting that it might have been somewhat terrestrial, although this hypothesis cannot be confirmed from bones of the postcranial skeleton (there are none). The known dental specimens show extremely heavy and rapid wear and the first molar tooth is far more worn than the last, suggesting that it included abrasive foods in its diet with very poorly developed cutting edges indicating a diet of fruit. One specimen retains a small part of the orbit and indicates that "Branisella" had small eyes and was diurnal.