Previous research suggests that the complex symbolic, technological, and socio-economic behaviors that typifyHomo sapienshad roots in the middle Pleistocene <200 ka, but data bearing on human behavioral origins are limited. We present a series of excavated Middle Stone Age sites from the Olorgesailie Basin, southern Kenya, dated ≥295 to ~320 ka by40Ar/39Ar and U-Series methods. Hominins at these sites made prepared cores and points, exploited iron-rich rocks to obtain red pigment, and procured stone tool materials from ≥25-50 km distance. Associated fauna suggests a broad resource strategy that included large and small prey. These practices imply significant changes in how individuals and groups related to the landscape and one another, and provide documentation relevant to human social and cognitive evolution.
