From pottery use-alteration to food habits: Perspectives from a 20th century Diola Kassa midden (Lower Casamance, Senegal)

• A use-alteration study uncovered the food habits of a 20th century village in Senegal. • The large size of the sample enabled a multivariate approach on use-alterations. • Methodological keys are detailed to distinguish use-alterations from post-depositional alterations. • The study brought information on the way of use, contents and types of contact on pots. • Repetition of use-alteration on morphotypes enabled the identification of pottery function. During the last decade, use-wear analysis on pottery has seen significant advances, both in the refining of reference collections and the application of this methodology to the archaeological material. Despite these contributions, the field has not yet paralleled the widespread dissemination achieved by lithic or bone materials. This paper aims to contribute to the methodology of the functional study of ceramic vessels and the interpretation of use-alterations. The method used is based on the determination of the main morpho-stylistic groups of a ceramic assemblage and their correlated use-alterations. It has been implemented on 365 pots and 3037 sherds from a well-preserved 20th century midden in Lower Casamance (Senegal), allowing for a statistically significant multivariate analysis. By delivering information on pottery way of use, content and the types of contact, this analysis has yielded significant results regarding the correlations between pottery use-alterations and morpho-types, revealing specialized functions. The study of way of use evidenced eight main functional categories (cooking, transporting, storing etc.), while content was evidenced by specific alterations (carbonate dissolution, spalls) and the intersection with organic residues analysis and phytolith analysis. Finally, the types of contact on some of the groups could be evidenced. In particular, distinction between abrasion types has provided insights on material hardness, while pattern distribution evidenced the use of different pottery closing systems, utensils and associated motions. The investigation of pottery function significantly contributes to the reconstruction of past culinary and craft practices.