The stone connection: Functional and microbotanical analysis of prehistoric macrolithic tools on the island of Formentera (Balearic Archipelago)

Formentera was one of the last Mediterranean islands to be colonized by humans at the end of the third millennium BC. This island is rather small (83km(2)) with marked biogeographical constraints. Typical of a semi-arid environment, the island is poor in resources and biodiversity. Macrolithic tools from the prehistoric sites of Ca na Costa (ca. 2130-1790 cal BC), Cap de Barbaria II (ca. 1740-900 cal BC), and Sa Cala (ca. 800-570 cal BC) showed similar technological, typological, and functional patterns documented in other prehistoric tool assemblages from the Balearic Islands. This common technology is reflected in the way the raw materials were procured, as well as the manufacture, the maintenance strategies, and the use of macrolithic tools (e.g., grinding stone tools, abraders, and percussion tools). Integrated phytolith and starch analyses from grinding toolkits show evidence of people's exploitating millet-tribe species (Paniceae) during the Bronze Age, cereals that are well-adapted to nutrient-poor soils, including exotic taxa such as possible foxtail millet (Setaria cf. italica). The production and use of this stone technology suggests how the first human communities on the island achieved and shared social knowledge about the insular landscape and its environmental constraints. This integrative archaeological research in Formentera has shown development of a set of innovative, diversified, and intensive resource exploitation strategies, underlining the high adaptability and resilience of prehistoric societies as well as the sharing of technology within the Balearic archipelago and its independent evolution from mainland technologies.