Gazing into the Voids: The Morphology of Shell Temper Reveals Pottery-Making Practices and Pottery Transfer among Hunter-Fishers in North-East Europe

Stereomicroscopic examination of bivalve shell fragments and especially voids from dissolved shell in hunter-fisher-gatherer pottery from Latvia (4th mill. BC) reveals several morphologies useful for characterisation of this tempering material, permitting new insights into pottery production and provenance. Observable in rare instances is the structure of the prismatic layer of unionid mussels. Much more common are concave–convex imprints, corresponding to the characteristic breakage pattern of burnt mussel shell, showing that it was heated before mixing with the clay. Imprints corresponding to the folds of lateral teeth and the pronounced relief of anterior muscle scars indicate the use of Unio sp. shell as pottery temper, correlating with the dominance of these freshwater mussels in food refuse. The characteristic texture of the shells of the marine bivalves Cerastoderma sp. is commonly observed in voids in pottery from coastal sites and has now also been identified in sherds from two sites in the Lake Lubāns basin, indicating that a proportion of the pottery recovered from this distant inland area was actually made at the coast. This is crucial new evidence for pottery transfer among hunter-fisher-gatherers in north-eastern Europe, with major implications for the interpretation of ceramic assemblages.