Center for the Advanced Study of Hominid Paleobiology, The George Washington University
Friday All day, Plaza Level
This study investigates post-natal growth of the maxillary and sub-nasal regions of Papio anubis, and seeks to identify patterns of bone growth remodeling that underlie morphological variation in the craniofacial skeleton among adults. Surface features reflecting bone cell formation and resorption activities were identified using reflected light and scanning electron microscopy to assess bone growth remodeling patterns. The sample utilized is that of well-documented individuals of known chronological age from the Southwest Primate National Research Center collection from the Washington University in St. Louis, Missouri.
The analysis revealed several interesting results, which have implications for understanding craniofacial sexual dimorphism in Papio anubis. Geometric morphometric analysis indicated that both sexes shared a common size/shape growth trajectory with late divergence beginning around four years of age. Investigation of bone remodeling activity demonstrated large depositional areas near the canine alveoli, maxillary tuberosity, and the premaxilla of both sexes during early ontogeny. These depositional areas were then replaced by bone resorption in the subnasal and zygomaxillary regions as individuals aged from four to approximately six years of age, corresponding with sexual maturity in females.
Despite differences in adult morphology between the sexes, results indicate that the spatial patterning and timing of bone formation and resorptive processes in the maxillary and subnasal regions of the face are similar during ontogeny. Future analyses aimed towards understanding differences in bone remodeling activity rates at these sites may provide further insight into the mechanisms underlying the evolution of sex differences in the adult craniofacial morphology of anubis baboons.
This study was funded by NSF IGERT DGE-0801634 and the Center for the Advanced Study of Hominid Paleobiology.