The analysis of stable carbon isotope ratios in tooth enamel is an established technique for quantifying diet in individuals up to millions of years old. Unlike bone collagen and apatite, enamel is not resorbed and thus comprises dietary components from the time of tooth formation rather than the last decade or so of an individual’s life. While analyses of large, homogenized samples of tooth enamel have proven useful in contrasting adult and juvenile diets, and even in the identification of weaning ages through the comparison of isotope ratios in teeth which form at different ages, our research on the microsampling of individual teeth shows significant intratooth variation in carbon isotope ratios.

Originally developed to minimize the destructive nature of isotopic analysis, especially in fossil hominid teeth, the removal and analysis of several milligrams or less of enamel powder presents both problems and possibilities for dietary interpretation. We demonstrate that a single sample may differ isotopically from another sample from a different tooth or different individual simply because of seasonal or other short-term variation in diet, rather than any general difference in overall dietary adaptation. On the other hand, multiple microsamples from single teeth can be used to identify seasonal or short-term dietary variation in individuals and populations. We present as an example results from the microsampling of teeth exhibiting enamel hypoplasia in which we attempt to correlate the pathological markers of dietary stress with short-term dietary changes as recorded in stable carbon isotope ratios.