Browsing by Author "Morse, PE"
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Item Open Access Adaptive wear-based changes in dental topography associated with atelid (Mammalia: Primates) diets(Biological Journal of the Linnean Society, 2018-06-28) Pampush, JD; Spradley, JP; Morse, PE; Griffith, D; Gladman, JT; Gonzales, LA; Kay, RFItem Open Access Introducing molaR: a New R Package for Quantitative Topographic Analysis of Teeth (and Other Topographic Surfaces)(Journal of Mammalian Evolution, 2016-12-01) Pampush, JD; Winchester, JM; Morse, PE; Vining, AQ; Boyer, DM; Kay, RF© 2016, Springer Science+Business Media New York.Researchers studying mammalian dentitions from functional and adaptive perspectives increasingly have moved towards using dental topography measures that can be estimated from 3D surface scans, which do not require identification of specific homologous landmarks. Here we present molaR, a new R package designed to assist researchers in calculating four commonly used topographic measures: Dirichlet Normal Energy (DNE), Relief Index (RFI), Orientation Patch Count (OPC), and Orientation Patch Count Rotated (OPCR) from surface scans of teeth, enabling a unified application of these informative new metrics. In addition to providing topographic measuring tools, molaR has complimentary plotting functions enabling highly customizable visualization of results. This article gives a detailed description of the DNE measure, walks researchers through installing, operating, and troubleshooting molaR and its functions, and gives an example of a simple comparison that measured teeth of the primates Alouatta and Pithecia in molaR and other available software packages. molaR is a free and open source software extension, which can be found at the doi:10.13140/RG.2.1.3563.4961 (molaR v. 2.0) as well as on the Internet repository CRAN, which stores R packages.Item Open Access Sign-oriented Dirichlet Normal Energy: Aligning Dental Topography and Dental Function in the R-package molaR(Journal of Mammalian Evolution, 2022-12-01) Pampush, JD; Morse, PE; Fuselier, EJ; Skinner, MM; Kay, RFDirichlet 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.