Dental morphology and mechanical efficiency during development in a hard object feeding primate (Cercocebus atys)

Teeth play a prominent role in food acquisition and processing by providing the working surfaces to initiate and propagate fracture. Variation in the shape and size of teeth has therefore naturally been associated with various dietary adaptations. However, few studies have actually tested the functional consequences of tooth form on food breakdown. The work presented in this thesis uses a combination of shape quantification and physical testing to further our understanding of the relationship between dental occlusal morphology and food breakdown in the dietary specialisation hard object feeding. The sooty mangabey, Cercocebus atys, is a primate that specialises in hard object feeding throughout its life, and so presents an interesting study group that will be of focus in this thesis. Individual cusps which vary in angle and bluntness performed differently (in terms of force, energy, duration and fragmentation) during food breakdown physical testing. Therefore trade-offs in dental occlusal morphology may have to occur when optimising for more than one performance criteria. This may in part explain the diversity of tooth form observed in hard object feeders. The morphology of C. atys molars changes considerably with age due to wear, with high sharp cusps in the juveniles wearing down to produce dentine pools surrounded by an enamel ridge in older individuals. Given the considerable change in dental occlusal morphology due to wear, performance is minimally effected in hard hollow object feeding, this is particularly relevant for the dietary ecology of C. atys suggesting functional equivalence in the tooth as it wears. This study reveals a complex relationship between dental occlusal morphology and dietary ecology.