Shungura Formation , Ethiopia

The microanatomy and macroanatomy of six Pliocene hominid molar teeth from Members F and G of the Shungura Formation (Omo basin, Ethiopia) are investigated. Teeth are assigned to “Morphs” on the basis of their combination of microanatomical characteristics: number of imbricational striae of Retzius and their contour through the extent of enamel. Crown and cusp areas establish the macroanatomical component of the study. The microand macroanatomical comparison reveals that while several enamel microanatomical variables naturally account for the size of teeth, strial contour must also be considered. Specifically, a boomerang-like strial shape to the enamel forming front provides for a larger base crown area than could be obtained with uniformly concave striae.