Anthropologists tend to overlook the New World monkeys because they are not on the main line of relationship to humans. Nevertheless, they comprise an exciting side branch which provides anthropologists with examples parallel to changes which have taken place in the catarrhine fossil record. The history of New World monkeys is still poorly known, compared with that of other major radiations of higher primates in the eastern hemisphere, and phylogenetic relationships among the relatively distinct groups of platyrrhine fossils are largely unresolved. Until very recently, the entire fossil record for platyrrhines consisted of remains of fewer than thirty individuals. During the past four years, paleontological research in Colombia and Argentina has yielded an abundance of new fossils that may be very important in sorting out these relationships. Further systematic and functional studies of new Argentine fossils will help clarify relationships among modern platyrrhines, and provide additional documentation about their adaptive diversity. The fossils from Argentina have come from two roughly contemporaneous formations, the Santa Cruz and the Pinturas, yet the two formations have different species of monkeys. This project will investigate the extent to which these morphological differences are the result of differences in time, environment, and/or geographical position of the two formations, and the PI will reconstruct the paleoenvironments of these formations. The project will contribute to our understanding of the phylogeny and diversification of New World primates, and permit broader comparisons between those in South America and those on other continents.
