The 81st Annual Meeting of the American Association of Physical Anthropologists (2012)

Does this face make my teeth look big? Molar size, size-adjustment, and dietary adaptation in strepsirrhine primates


Department of Biological Sciences, University of Notre Dame

Thursday 8:00-8:15, Broadway III/IV Add to calendar

Among the Strepsirrhini, relative molar size does not exhibit a dietary signal when body mass is used to scale molar dimensions. This observation is also true for anthropoid primates, but when the size of the facial skeleton is used to scale postcanine dimensions in this clade, folivores tend to have relatively larger postcanine teeth than frugivores. Notably, facial size appears to have a stronger influence than body mass on postcanine size in anthropoids, suggesting that facial size is the more appropriate variable for size-adjusting the postcanine dentition. The goal of this study was to determine whether this pattern of relationships also characterizes strepsirrhines. Data on molar area, skull size (a geometric mean composed primarily of measurements of the facial skeleton or the facial skeleton’s interface with the neurocranium), and body mass for thirty-seven extant strepsirrhine species were taken from the literature and analyzed using phylogenetic comparative methods. Results indicate that strepsirrhines are similar to anthropoids: when skull size is used to size-adjust molar area, folivores tend to have relatively larger molars than frugivores and insectivores. Moreover, the partial correlation between molar area and skull size holding body mass constant is strong and highly significant, whereas the partial correlation between molar area and body mass holding skull size constant is weak and nonsignificant. These results confirm the generality of the anthropoid pattern and support the idea that elements of the masticatory system should, in some contexts, be considered relative to their functional and developmental environments in studies of dietary adaptation.

Support for this research was provided by NSF grant BCS-1029149.

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