The upper dentition of Stirtonia (Ceboidea, Primates) from the Miocene of Colombia, South America and the origin of the Postero-internal cusp of upper molars of howler monkeys (Alouatta).

Abstract

Ecological studies of two sympatric species of genus Saguinus were carried out with special reference to difference of forest utilization in western Pando, Bolivia from July to December 1979. Saguinus fuscicollis weddelli and S. labiatus labiatus made intraspecifically territoriastic groups consisting of 2 to 7 individuals and often made interspecifically associated groups. They moved in associated groups in the day time. However, there were differences in height preference for moving and in the size of the insects consumed by the 2 species. The animals also had their own parturition seasons and sleeping sites. S. labiatus is larger than S. fuscicollis in body size, and the intermembral index showed a larger value for S.fuscicollis than for S. labiatus.