Pervasiveness of phytoliths in prehistoric southwestern diet and implications for regional and temporal trends for dental microwear

Our previous analysis of phytolith content of coprolites showed that calcium oxalate phytoliths from desert food plants caused dental microwear among prehistoric Texas hunter-gatherers. We demonstrated that phytoliths from desert succulents were ubiquitous and abundant in hunter-gatherer coprolites. We found that calcium oxalate phytoliths were harder than human dental enamel. We concluded that phytoliths from desert succulent plants caused dental microwear and hypothesized that such dental microwear would be common in other desert hunter-gatherer and horticultural peoples. Presented here are further analyses of phytoliths from coprolites. Two additional hunter-gatherer sites and three Ancestral Pueblo (Anasazi) horticultural sites are included in this study. Calcium oxalate phytoliths are ubiquitous in coprolites from hunter-gatherer sites in the Mojave Desert and the Colorado Plateau. For the three Ancestral Pueblo sites, calcium oxalate phytoliths from desert succulents (agave family and cactus family) are the most common types of phytoliths encountered. However, silica phytoliths are also present in Ancestral Pueblo coprolites. The data demonstrate that phytoliths from non-cultivated desert plants were a source of dental microwear for the pre-maize Archaic hunter-gatherer bands and maize-reliant Ancestral Pueblo villages.