More than acorns and small seeds: A diachronic analysis of mortuary associated ground stone from the south San Francisco Bay area

► Ground stone milling tools were integral to economic and social transformations in central California prehistory. ► Synchronic and diachronic variability exists among mortuary associated ground stone artifacts. ► Archaeological and ethnographic evidence supports the association of certain mortars with feasting and ritual activities. ► Changes in the status of women and men, and roles in community ritual and politics are explored. ► Ground stone tools offer an important and often overlooked source of data for considering social changes in prehistory.