Journal of California and Great Basin Anthropology

A database of marine shell from 70 archaeological assemblages at Vandenberg Air Force Base reveals substantial temporal and spatial variability in the distribution of turban snails (Tegula spp.). Consideration of both variables is crucial to identi cation of diet breath expansion in the context of subsistence stress and resource diversification. At Vandenberg AFB, increased use of Tegula during late prehistory strongly correlates with spatial proximity to prime Tegula habitat (Purisima Point) at sites on a landform that is less than 2,000 years old. When sites near prime habitat are excluded, increased Tegula use correlates very poorly with time, and long-term diet breath expansion to include a lower-ranked species is not supported. However, the evidence does point to short-term increased use of Tegula during the Medieval Climatic Anomaly, a time of known environmental stress.