Dental Microwear Evidence for a Dietary Shift Between Two Nonmaize-Reliant Prehistoric Human Populations From Indiana Christopher W. Schmidt* Archeology and Forensics Laboratory, University of Indianapolis, Indianapolis, Indiana 46227 KEY WORDS dental wear; diet; bioarcheology ABSTRACT Several recent studies have demon- strated the efficacy of dental microwear analysis (DMA) for dietary reconstruction among nonhuman primates, early hominids, and prehistoric humans. The current study seeks microwear evidence for a paleobotanically suggested change in the types of foods that were consumed by two temporally distinct populations of the North Amer- ican eastern woodlands. This particular dietary shift be- tween the Late Archaic and the Early/Middle Woodland periods did not include the introduction of maize or any other tropical cultigen. In contrast, most dietary recon- structions from this area have compared later populations that consumed tropical cultigens (such as maize) with those that did not. High-resolution casts of adult mandib- ular second molar protoconid phase II wear facets were viewed via a scanning electron microscope at 500. Pho- tomicrographs of the microwear features were analyzed with specialized software, Microware 2.2 (Ungar [1995] Scanning 17:57–59). Analysis of variance statistical tests were performed, with one variable requiring rank-trans- formation. A dietary transition is evidenced by a statisti- cally significant increase in the mean number of pits and concomitant decreases in scratch width and scratch length from the Late Archaic to the Early/Middle Woodland. Overall, the diet became harder and less abrasive. The implication here is that dental microwear analysis is able to discern relatively subtle dietary transitions in human populations that may not be as readily accessible by other means of dietary reconstruction. Am J Phys Anthropol 114:139 –145, 2001. © 2001 Wiley-Liss, Inc. Of the dietary reconstructions that have focused on prehistoric humans from the eastern woodlands of North America, the preponderance have illus- trated the consequences of adopting maize agricul- ture as a primary means of subsistence (e.g., Lynott et al., 1986; Buikstra et al., 1987, 1988, 1994; Larsen et al., 1992). While the transition to maize agricul- ture around 1,000 years ago was an enormously important event, it was not the only subsistence shift to take place prehistorically in this region (Chapman and Shea, 1981; Yarnell and Black, 1985; Wymer, 1993). In fact, if the paleobotanical record is at all indicative of dietary shifts, several changes in diet occurred before maize agriculture took hold. The current study seeks to detect a dietary tran- sition between representative skeletal samples from the Late Archaic and Early/Middle Woodland tem- poral periods in Indiana via dental microwear anal- ysis (DMA). This avenue of study has proven valu- able in the reconstruction of diet for nonhuman primates (e.g., Gordon, 1982; Teaford and Walker, 1984; Teaford and Oyen, 1989; Teaford and Robin- son, 1989; Ungar, 1994), early hominids (e.g., Grine, 1981, 1987a,b; Kay and Grine, 1988; Ungar and Grine, 1991; Lalueza et al., 1993, 1996), and recent humans (e.g., Moore-Jansen, 1981; Rose et al., 1981; Rose, 1984; Rose and Marks, 1985; Gordon, 1986; Bullington, 1991; Teaford, 1991; Pastor, 1993; Schmidt and Nawrocki, 1996; Ungar and Spencer, 1999). For the most part, DMA has been employed to understand the sizes and frequencies of occlusal mi- crofeatures (pits and scratches) on molars (e.g., Rose, 1984; Rose and Marks, 1985; Teaford, 1991) and incisors (e.g., Ryan, 1981; Ryan and Johanson, 1989; Ungar, 1994; Ungar and Spencer, 1999). Pits tend to be created by food items that require more masticatory demand and/or are inherently hard enough to microscopically fracture the tooth surface. Scratches are thought to be caused by exogenous grit and/or phytoliths adhering to or within what is consumed. However, it is possible that pits and scratches can be caused by the same agent. For example, exogenous grit in one diet may cause pit- ting, while that same grit in another diet may leave only scratches. Therefore, the sizes and frequencies of microwear features vary depending on the general type of foods upon which an organism relies. Animals that eat Grant sponsor: Indiana Academy of Science; Grant number: 95-125. *Correspondence to: Christopher W. Schmidt, Ph.D., Archeology and Forensics Laboratory, University of Indianapolis, 1400 E. Hanna Ave., Indianapolis, IN 46227. E-mail: cschmidt@uindy.edu Received 10 March 2000; accepted 20 October 2000. AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY 114:139 –145 (2001) © 2001 WILEY-LISS, INC.