1Center for the Study of Human Origins, Department of Anthropology, New York University, 2NYCEP, New York Consortium in Evolutionary Primatology
March 27, 2015 , Archview Ballroom
Variation in sexual selection mechanisms according to differences in mating systems and competitive regimes leads to variation in reproductive traits. A major challenge in paleoanthropology is reconstructing the behavioral strategies of extinct hominins represented only by fossils. Canine size and estimates of body size are used to infer sexual dimorphism as a proxy of socio-sexual behavior; however, these are somewhat limited and other bony correlates of soft tissue sexual traits may be more informative. This study assesses the cheek flanges that characterize adult male drills (Mandrillus leucophaeus) but not closely related mandrills (Mandrillus sphinx) in an attempt to identify potential osteological markers that characterize this secondary sexual characteristic. To quantify bony correlates of cheek flanges, a suite of cranial measurements was taken in addition to the non-metric quantification of zygomaticofacial foramina, which house the vessels that innervate and vascularize the fleshy cheek pads. The results show that adult male drills are characterized by wider zygomatics (and wider faces overall) and a higher number of zygomaticofacial foramina than mandrills. This suggests that this soft tissue trait can be identified in craniofacial skeletal morphology in the genus Mandrillus, which has implications for the identification of fleshy cheek flanges in fossil primates.