New insights into prehistoric agriculture of northern Iberia from the analysis of starch grains embedded in dental calculus

Borja González-Rabanal^1,2*Ana B. Marín-Arroyo^2*Eduardo Carmona-Ballestero^3,4David Cuenca-Solana⁵Igor Gutiérrez-Zugasti⁵Miguel Ángel Martín-Merino⁶Ana Isabel Ortega-Martínez⁷Lawrence G. Straus⁸Cristina Vega-Maeso⁹Manuel R. González Morales⁵Emanuela Cristiani^10*

• ¹Departamento de Prehistoria, Arqueología, Antropología Social y Ciencias y Técnicas Historiográficas, University of Valladolid, Valladolid, Spain
• ²Grupo I+D+i EvoAdapta, (Evolución Humana y Adaptaciones durante la Prehistoria), Departamento de Ciencias Históricas, Universidad de Cantabria, Santander, Spain
• ³Servicio Territorial de Cultura, Turismo y Deporte de Valladolid, Junta de Castilla y León, Valladolid, Spain
• ⁴Universidad de Burgos, Burgos, Spain
• ⁵Instituto Internacional de Investigaciones Prehistóricas de Cantabria (Universidad de Cantabria, Banco Santander, Gobierno de Cantabria), Santander, Spain
• ⁶Sociedad Española de Espeleología y Ciencias del Karst, Fundación Gómez Pardo, Madrid, Spain
• ⁷Real Academia Burgense de Historia y Bellas Artes, Institución Fernán González, Burgos, Spain
• ⁸Department of Anthropology, University of New Mexico, Albuquerque, United States
• ⁹Servicio Territorial de Cultura, Turismo y Deporte de Segovia, Junta de Castilla y León, Segovia, Spain
• ¹⁰DANTE‑Diet and ANcient TEchnology Laboratory, Department of Oral and Maxillo‑Facial Sciences, Sapienza University of Rome, Rome, Italy

Research on the origin and spread of agriculture in northern Atlantic Iberia remains partially limited because archaeobotanical data are scarce due to old excavations or preservation biases. In this paper, we present starch grain analyses of dental calculus of 18 individuals from 10 sites dated to the 4th/2nd millennium cal BC. This research supports the development of extensive and stable agriculture, based on the cultivation of wheat and barley species, from the Neolithic to the Bronze Age, when millets were introduced, marking the primary shift of the Cantabrian farming economy and revealing a more diversified and mixed agriculture thereafter. In parallel, legumes were less cultivated since the Neolithic and probably used as a secondary plant resource by the Cantabrian communities. Our results have also allowed us to corroborate previous regional archaeobotanical and isotopic data and enhance the archaeological evidence of plant consumption during Late Prehistory, establishing a diachronic multiapproach to the development of agricultural practices in this area and providing a methodological framework for future studies.