Readjustment of the Standard ASUDAS to Encompass Dental Morphological Variations in Plio-Pleistocene Hominins

Abstract

The standard ASUDAS scoring system (Arizona State University Dental Anthropology System) is used to assess dental morphological variations in modern humans. It is also frequently used to study, score, and compare morphological variations in fossil hominin taxa and to examine their phylogenetic relationships. However, using ASUDAS in studies of this type is under debate because it is based on modern Homo sapiens populations and does not appear to cover all variations observed in fossil Plio-Pleistocene homi- nins. Our observations and coding of 178 dentals casts of Plio-Pleistocene specimens based on ASUDAS and from the literature have confirmed the need to adapt the standard system to fossil hominins. In this initial study, we propose that the scoring procedures for some morphological characters need to be readjusted, while others could be standardized following the ASUDAS system.

A human lower third molar from the Acheulean site of Cueva del Ángel (Lucena, Córdoba, Spain)

“…Unworn features at the OES were primarily described according to the degrees of expression of the Arizona State University Dental Anthropology System (ASUDAS) (Turner et al, 1991). Since the ASUDAS does not fully cover the variability observed in fossil hominins (Louail & Prat, 2018; Martinón‐Torres et al, 2008, 2012) nor does it focus on the internal dentine morphology, we follow Skinner (2008) and Skinner et al (2008, 2009) in the description of the protostylid, as they consider that it can be expressed along different regions of the buccal face of lower molars and, accordingly, the definition of the trait should not be limited to the region of the buccal groove. The trigonid crest pattern was described and classified, at both enamel and dentine surfaces, according to Martínez de Pinillos et al (2014), whereas the talonid crest was scored following Korenhof's classification (Korenhof, 1982).…”

Evaluating the patterning cascade model of tooth morphogenesis in the human lower mixed and permanent dentition

“…Dental anthropological analyses often utilize nonmetric crown traits to assess the degree of similarity among global populations [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17], detect biological kinship within a site [18][19][20][21][22][23][24][25][26][27][28][29], establish phylogenetic relationships across taxa [30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47][48][49], explore the population history associated with specific groups or geographic regions , and more recently, to...…”