Dental Microwear Texture and Anthropoid Diets Robert S. Scott, 1 * Mark F. Teaford, 2 and Peter S. Ungar 3 1 Department of Anthropology, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901 2 Department of Physical Therapy, School of Health Sciences, High Point University, High Point, NC 27262 3 Department of Anthropology, University of Arkansas, Fayetteville, AR 72701 KEY WORDS dietary variability; food mechanical properties; dental anthropology; primate ABSTRACT Dental microwear has long been used as evidence concerning the diets of extinct species. Here, we present a comparative baseline series of dental micro- wear textures for a sample of 21 anthropoid primate species displaying interspecific and intraspecific dietary variability. Four dental microwear texture variables (complexity, anisotropy, textural fill volume, and hetero- geneity) were computed based on scale-sensitive fractal analysis and high-resolution three-dimensional render- ings of microwear surfaces collected using a white-light confocal profiler. The purpose of this analysis was to assess the extent to which these variables reflect varia- tion in diet. Significant contrasts between species with diets known to include foods with differing material properties are clearly evident for all four microwear tex- ture variables. In particular, species that consume more tough foods, such as leaves, tended to have high levels of anisotropy and low texture complexity. The converse was true for species including hard and brittle items in their diets either as staples or as fallback foods. These results reaffirm the utility of dental microwear texture analysis as an important tool in making dietary inferences based on fossil primate samples. Am J Phys Anthropol 147:551–579, 2012. V V C 2012 Wiley Periodicals, Inc. The primate radiation is characterized by diverse die- tary strategies, and the study of living primate diets pro- vides one key for interpreting fossil hominin diets. Other clues have come from analyses of masticatory anatomy and adaptations in their comparative context (Strait et al., 2009; Grine et al., 2010; and references therein) as well as inferences based on topics as disparate as stable isotopes (e.g., Sponheimer et al., 2006) and genetics (e.g., Perry et al., 2007). Another line of evidence is provided by microscopic wear preserved on fossil teeth, which can be used to infer the material properties of foods con- sumed just prior to death. A comparative baseline of pri- mate dental microwear surfaces paired with the study of primate diets in the wild has great potential as an aid to the reconstruction of food preferences and subsistence strategies in fossil species, and might be a powerful com- plement to dietary inferences that flow from other lines of evidence. However, recent research on dental microwear and pri- mate diets has made two points increasingly clear: 1) extant primate diets are complex, flexible, and variable; and 2) dental microwear is also variable and presents intrinsic obstacles with respect to repeatable quantifica- tion of microwear surfaces. Although a link between observations of dental microwear on occlusal wear facets and general diet categories has long been substantiated (Teaford, 1988a; Ungar et al., 2008b), workers still argue that dental microwear has not yet lived up to its full potential (Teaford, 2007; Ungar et al., 2008b). Grine et al. (2002) pointed to high levels of observer measure- ment error in dental microwear feature analyses, even when employing scanning electron microscopy for imag- ing surfaces. Another significant difficulty in pushing dental microwear to its potential is the limited nature of most studies of primate diets in the wild. Methods of data collection vary dramatically from study to study, and very few describe dietary preferences and strategies in terms of both food material properties and dietary variability on various geographic and temporal scales (e.g., microhabitat, regional, altitudinal, seasonal, pheno- logical; Teaford and Glander, 1991, 1996; Teaford et al., 2006; see Teaford and Robinson, 1989). For instance, Conklin-Brittain et al. (2000) reviewed the literature on ape diets and found dramatic variability in diets among common chimpanzees, with reports from 24 studies evincing a range of percent fruit consumed of 19–99%. These studies also rarely mention the variety of fruit parts eaten and their fracture properties, which vary from soft and tough, to hard and brittle (Dominy et al., 2008; Norconk et al., 2009; see Vogel et al., 2009 for some of the rare exceptions this statement; Vogel et al., 2008; Wright et al., 2009). We would expect very differ- ent dental microwear signals to result from a diet of 19% hard fruit endocarp (on one extreme) compared to one of 99% soft fruit mesocarp (on another). Of further interest, behavioral observations of prima- tes in the wild increasingly demonstrate that summary- type characterizations of masticatory adaptations are of- ten not well matched with actual food preferences. For example, Lophocebus albigena, with its relatively thick enamel and other craniodental specializations, was long Additional Supporting Information may be found in the online version of this article. Grant sponsors: US National Science Foundation, LSB Leakey Foundation. *Correspondence to: Robert S. Scott, Department of Anthropology, 131 George Street, RAB 306, New Brunswick, NJ 08901-1414, USA. E-mail: robertsc@rci.rutgers.edu Received 31 May 2011; accepted 27 November 2011 DOI 10.1002/ajpa.22007 Published online 13 February 2012 in Wiley Online Library (wileyonlinelibrary.com). V V C 2012 WILEY PERIODICALS, INC. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 147:551–579 (2012)