The 87th Annual Meeting of the American Association of Physical Anthropologists (2018)

Differential Enamel Thickness in the Anterior Dentition as a Signal for Gouging Behavior


1Department of Anthropology, University of Toronto Scarborough, 2Roman Kozłowski Institute of Paleobiology, Polish Academy of Sciences, 3Department of Biological Sciences, North Carolina State University, 4Department of Physical Therapy, Duquense University

April 13, 2018 , Zilker 1/2/3 Add to calendar

Exudativory poses unique dental challenges, since acquisition of exudates requires that the anterior teeth engage with a substrate that is often tougher than any components of the species’ diet. Since enamel interacts directly with the substrate from which exudates are recovered, it could be predicted that patterns of enamel thickness may be influenced by that interaction. Examining patterns of enamel thickness in primates and other gouging mammals serves as an opportunity to better understand this dietary niche, and potentially test hypotheses about the dietary adaptations of fossil taxa.

Measurements of lingual and labial enamel thickness were taken on micro-CT scans for the anterior teeth of primates (n=13), bats (n=9), and marsupials (n=6), including both gouging and closely related non-gouging taxa. Tooth position examined was determined based on the part of the dental battery used during gouging.

Our results suggest that obligate gouging primates and marsupials are characterized by relatively thicker labial than lingual enamel, when compared to the relative enamel thicknesses of their non-obligate gouging or non-gouging kin. It is likely that this pattern of thick labial enamel and thin lingual enamel evolved to keep a sharp incisal edge on the tooth to better pierce the substrate, as lingual enamel wears away in life. Differential enamel distribution is also present in the canines of vampire bats, although in a pattern specific to their unique behaviors. Our findings suggest that enamel carries a signal for gouging and could be used to interpret feeding adaptations of extinct taxa.

Supported by an NSERC Discovery Grant to MTS; Supported by Pilot Funding from the University of Toronto Department of Anthropology to KRS