Ostrich eggshell bead size variation: The impacts of material and technology on bead diameter

Abstract

This research explores the impact of non-stylistic variables such as drilling technology and eggshell thickness on the size of ostrich eggshell beads. Since external bead diameter is thought to reflect culturally informed preferences, differences in external diameter across space and time have been used to identify distinct populations and to infer migration and culture change. Conversely, our analysis of archaeological and experimental data shows that material and technological biases significantly contribute to the size of beads. Specifically, we show that shell thickness contributes to variance in external bead diameter. As such, we argue that assemblage or regional scale differences might not always represent different cultural groups with their own material traditions.