Meeting Abstract

33.3  Wednesday, Jan. 5  Functional correlates of tooth structure in bats SANTANA, S.E.*; DUMONT, E.R.; UMass Amherst / UCLA; UMass Amherst ssantana@bio.umass.edu

The morphology and function of mammalian teeth are strongly linked to diet. Within mammals, phyllostomid bats are the most diverse group in terms of dietary ecology and thus represent a unique system in which to investigate the relationship among diet, tooth structure, feeding performance and behavior. Here we use a novel measure of 3D dental structure called dental complexity, which has been successfully used to describe differences between mammalian herbivores and carnivores. We use dental complexity to document differences in the molars of insectivorous, omnivorous and frugivorous phyllostomids. For the first time, we investigate the functional significance of molar complexity with respect to the breakdown of prey naturally included in the diet of insect-eating species. We conducted laser scans of the molars of 17 phyllostomid species to estimate their complexity, and feeding experiments using native prey to collect data on feeding performance (ability to break down insects) and behavior (number of chews). We found that frugivores have very high molar complexity when compared to insectivores and omnivores, a characteristic that can be related to morphologies specialized for biting into and crushing fruit pulp. The lower complexity of insectivore and omnivore molars can be related to the presence of shearing cusps specialized for cutting through insect exoskeleton. Increases in the complexity of these shearing surfaces translated into higher performance in prey breakdown, but chewing behavior also played a very important role in this function. Together, our results highlight the importance of tooth structure and behavior in determining feeding performance, which potentially contributes to resource partitioning within this diverse group of mammals.