Conference Presentations by Marian Hamilton
Sr/Ca Ratios Measured via Nondestructive XRF Differentiate Frugivory and Folivory in Early North American Primates , 2024
Assessing contributions of frugivory and folivory to primate diets is critical across the evoluti... more Assessing contributions of frugivory and folivory to primate diets is critical across the evolutionary history of the primate clade. The rise of euprimates was almost certainly related to arboreality, but the debate over the relative importance of visual predation (insectivory) or coevolution with fruiting angiosperms continues. Dietary reconstructions of late-Paleocene, early-Eocene euprimates is highly variable and based primarily on morphology. Such adaptive proxies for diet are often confounded by phylogenetic issues, and non-adaptive reconstruction methods would be an important contribution to the paleontological toolkit. Studies in extant primates show frugivores have lower Sr/Ca ratios than folivores. It is unclear if such methods are transferable to samples spread across time and space. This pilot study presents trace element data gathered via non-destructive XRF measurements on early euprimates and plesiadapaformes from the collections at the University of Wyoming’s Geology Museum including the genera Microsyops, Cantius, Smilodectes, Notharctus, Teilhardina, and Tetonius. Initial results show elevated Sr/Ca ratios in the likely-folivorous Smilodectes and Notharctus specimens compared to the likely-frugivorous Cantius specimens. However, Sr/Ca ratios of Cantius are not as low as the frugivorous Hyracotherium, and the likely-frugivorous Microsyops has ratios more similar to folivores than frugivores. Omnivorous Teilhardina and Tetonius have the most elevated Sr/Ca ratios, which could be consistent with insectivory, although modern analogous datasets are currently lacking. These findings are encouraging for future use of Sr/Ca ratios as a means of reconstructing diet even in complex datasets. Larger comparative modern samples and greater fossil samples sizes are necessary to resolve lingering questions.
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Conference Presentations by Marian Hamilton