Restitutio ab initio: Direct dating and isotopic evidence to evaluate the proxy reliability of intrusive archaeobotanical remains

Recovering archaeobotanical remains from archaeological contexts often entails substantial methodological challenges. Flotation and environmental sampling routinely yield charred seeds whose cultural attribution does not necessarily correspond to the stratigraphic position or inferred chronology of the deposits in which they occur. Direct radiocarbon dating frequently exposes marked discrepancies, demonstrating that intrusive seeds may derive from much later occupations than the layers that contain them. Such materials are commonly excluded from analysis, either because they are deemed intrusive or because their taxa are not otherwise attested in the archaeological period represented by the context. We argue, however, that within multi-stratified and multi-period sites—where different occupational phases have been explored with uneven intensity—intrusive carpological remains can constitute informative, and at times indispensable, proxies for reconstructing underdocumented episodes of site use, provided their chronological and taphonomic status is verified through direct radiocarbon and stable isotope analysis.This study presents new radiocarbon and stable isotope data for charred millet grains recovered from the Gumelnița site in southeastern Romania. Two broomcorn millet ( Panicum miliaceum ) grains and one foxtail millet ( Setaria italica ) grain were directly dated, placing their presence in the second half of the second millennium BC and the beginning of the first millennium BC. The foxtail millet grain constitutes the earliest securely dated occurrence of this species in Europe. These results demonstrate that intrusive grains, when robustly identified through direct testing, can serve as reliable proxies for documenting later occupational or depositional events superimposed upon earlier archaeological layers.