Snakes and Ladders: A technological approach to tool maintenance by-products using module flake categories

The study of retouching, reshaping, and rejuvenation in lithic technology has traditionally focused on finished tools, overlooking the by-products of these processes, particularly microdebitage. This has led to an incomplete understanding of the dynamic behaviours associated with tool maintenance and a lack of crucial information about prehistoric technological strategies. Here we address this knowledge gap. Specifically, we introduce a classification system for lithic by-products resulting from retouching, reshaping, and rejuvenation techniques, categorising them into five modules (M0 through M4) based on lithic technological analysis. This methodology integrates the chaîne opératoire approach to analyse flakes without size thresholds. To demonstrate our approach, we apply it, coupled with raw material sourcing, to lithic assemblages from two Middle Palaeolithic sites in Armenia, Kalavan 2 and Ararat-1 Cave. This enables a precise reconstruction of tool use-life and, in turn, the mobility strategies of Pleistocene hunter-gatherers. Our findings demonstrate that microdebitage (by-products) can contribute to a holistic view of decision-making, revealing patterns in tool maintenance and raw material provisioning. The module system provides insights into the production of ‘ghost tools,’ which are not present in the archaeological record, as well as curation behaviours and economic decisions regarding raw materials that were previously difficult to discern. By shifting the focus from finished artefacts to by-products, this framework enhances our ability to interpret lithic assemblages and understand the adaptive strategies of prehistoric hunter-gatherers.