Molar crests and body mass as dietary indicators in marsupials
Aaron S. Hogue A B and Shakila ZiaShakeri AA Salisbury University, Department of Biological Sciences, 1101 Camden Avenue, Salisbury, MD 21801, USA.
B Corresponding author. Email: ashogue@salisbury.edu
Australian Journal of Zoology 58(1) 56-68 https://doi.org/10.1071/ZO09084
Submitted: 13 August 2009 Accepted: 27 February 2010 Published: 7 April 2010
Abstract
The discovery of ecomorphological relationships in mammals is important not only in its own right, but also for its potential in shedding light on the ecology of extinct and poorly known species. Two such potential relationships are the proposed connection between molar shear crests and body mass to diet. Research on primates suggests that, owing to the digestive challenges of structural carbohydrates (in foliage and insects), folivores and insectivores differ from other species in needing relatively long molar shear crests. These studies also suggest that metabolic constraints force folivores to be consistently larger than insectivores, with 500–700 g being the proposed body mass boundary between the two. This study tests these proposed ecomorphological links in a diverse sample of 64 marsupial species. As predicted, folivores and insectivores have significantly relatively longer molar shear crests than other species. Similarly, folivores are significantly larger than insectivores, as predicted, though the proposed body mass boundary was not supported. These results suggest that shear crest length and body mass are indeed linked to diet in the proposed manner. It may now be possible to use these findings to gain a greater understanding of the feeding behaviours of a variety of extinct marsupials and other therians.
Acknowledgements
We are extremely grateful to M. Ravosa, M. Dagosto, B. Shea, R. Kay, and J. Flynn for their extensive guidance in the development, completion, and publication of this research. We thank S. Stephens and L. Salas for providing data before publication. Lastly, we thank the following for allowing access to museum collections: R. Voss, C. Norris, and B. Randall (American Museum of Natural History), M. Archer, T. Ennis, and S. Ingleby (Australian Museum), P. Jenkins (British Museum of Natural History), L. Heaney, B. Patterson, and W. Stanley (Field Museum of Natural History), L. Abraczinskas and B. Lundrigan (Michigan State University Museum), L. Frigo (Museum of Victoria), L. Gordon and R. Thorington (Smithsonian Institution), T. Flannery, D. Stemmer, and C. Kemper (South Australian Museum). This research was funded by generous grants from the American Society of Mammalogists, the National Science Foundation (Grant # NSF BCS-0127915), and Sigma Xi.
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