The Trail Creek tooth preserves, in addition to its dental morphology and its DNA, a chemical record of the environment in which the child lived.

Stable isotope analysis — the measurement of the ratios of different stable isotopes of elements like carbon and nitrogen in the tooth’s organic material — can in principle provide information about diet and about the geographic sources of the nutrients that built the child’s tissues.

Carbon stable isotopes in teeth reflect the types of plants that formed the basis of the diet, either directly or through consumption of animals that had eaten those plants.

The distinction between what are called C3 plants (most temperate and Arctic vegetation) and C4 plants (most tropical grasses and some other plants) is reflected in the carbon isotope ratios of the tissues of animals that consume them.