Sign-oriented Dirichlet Normal Energy: Aligning Dental Topography and Dental Function in the R-package molaR
Abstract
Dirichlet normal energy (DNE) is a dental topography measurement aimed at capturing
occlusal sharpness and has shown promise for its ability to sort primate molars according
to perceived shearing ability. As initially implemented, this measurement does not
differentiate concave versus convex contributions to surface sharpness. This is problematic
because the DNE-signal derived from concave aspects of an occlusal surface measures
a sharp ‘edge’ oriented inward towards the enamel dentine junction rather than outward
towards food contact. The inclusion of concave DNE in dietary analyses of molars possessing
deep occlusal sulci–such as those found among hominoids–inflates the perceived functional
sharpness of these teeth. Concave-inflated DNE values can be misleading, being interpreted
as indicating that a particular taxon is more adapted for processing fibrous food
than is warranted. The modification of the DNE measurement introduced here ‘Sign-oriented
DNE’ alleviates this problem by elimination of concave sharpness from analyses, allowing
investigations to focus on features of occlusal surfaces plausibly linked to shearing,
cutting, or shredding of food materials during Phases I and II of the masticatory
power stroke. Convex DNE is just as effective at sorting non-hominoid primate molars
into traditional dietary categories as the initial applications of the orientation-blind
version of the measurement, and produces more theoretically coherent results from
hominoid molars. Focusing on- and improving the connection between measurement and
occlusal function will enhance the ability of dental topography to make meaningful
contributions to our collective understanding of species’ dietary ecologies.
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https://hdl.handle.net/10161/26487Published Version (Please cite this version)
10.1007/s10914-022-09616-6Publication Info
Pampush, JD; Morse, PE; Fuselier, EJ; Skinner, MM; & Kay, RF (2022). Sign-oriented Dirichlet Normal Energy: Aligning Dental Topography and Dental Function
in the R-package molaR. Journal of Mammalian Evolution, 29(4). pp. 713-732. 10.1007/s10914-022-09616-6. Retrieved from https://hdl.handle.net/10161/26487.This is constructed from limited available data and may be imprecise. To cite this
article, please review & use the official citation provided by the journal.
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Richard Frederick Kay
Professor of Evolutionary Anthropology
I have two areas of research:1) the evolution of primates in South America; and 2)
the use of primate anatomy to reconstruct the phylogenetic history and adapations
of living and extinct primates, especially Anthropoidea. 1) Evolution of primates
and mammalian faunal evolution, especially in South America. For the past 30 years,
I have been engaged in research in Argentina, Bolivia The Dominican Republic, Peru,
and Colombia with three objectives:a) to reconstruct the evol
Paul Morse
Postdoctoral Associate
Dietary ecology of extant and extinct primates, particularly at the time of major
phylogenetic divisions (e.g., strepsirrhines & haplorhines, hominoids & cercopithecoids).
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