Dental topography and diets of platyrrhine primates

Abstract

More than half a century ago, Percy Butler touted the importance of analyzing teeth to understand their function in an evolutionary context. There have been many advances in the study of dental functional morphology since that time. Here we review the various approaches to characterizing and comparing occlusal form that have been developed, especially dental topographic analysis. We also report on a new study of dental topography of platyrrhine primates (n = 341 individuals representing 16 species) with known differences in both dietary preferences and other food items eaten. Results indicate frugivores, gummivores, folivores, and seed eaters each have a unique combination of slope, relief, angularity, sharpness, and occlusal orientation patch size and count values. Likewise, among frugivores, those that supplement their diets with hard objects, insects, leaves, and seeds, also each have a distinctive suite of topographic features. We conclude that both primary and secondary diet choices select for occlusal form, and that functional morphology more reflects the types of foods and mechanical challenges they pose rather than the frequencies in which they are eaten.

Keywords:

• New World monkeys
• teeth
• food

Acknowledgements

We thank curators at the Museum of Comparative Zoology in Cambridge, MA, The Field Museum of Natural History in Chicago, the American Museum of Natural History in New York, the US National Museum of Natural History in Washington, DC, and the Museu Paraense Emilio Goeldi in Belém, Brazil for access to specimens in their care and their hospitality during our visit. We are also grateful to David Polly and Doug Boyer for comments on an earlier version of this manuscript. Three of us (PSU, MF, MFT) were fortunate to have interacted with Percy Butler. He and his many works were inspirational to generations of dental researchers, and his legacy will remain with discipline for generations to come.

Notes

1. These models are technically 2.5D. While they are represented as a cloud of points with x, y, and z coordinates, they’re not truly 3D because surface elevation is not independent of the horizontal coordinate axes – there is only one z-value possible for a given x-y pair (Turner 1997).