Moving peoples, changing diets: isotopic differences highlight migration and subsistence changes in the Upper Mun River Valley, Thailand

► Dietary isotopes show increased reliance on C3 crops from the end of the Neolithic. ► This coincides with an increase in social differentiation in terms of mortuary wealth at the site. ► Oxygen isotopes show drier environmental conditions in the Iron Age. ► Climate change correlates with a decrease in reliance on C3 crops. ► Unusual mortuary practice e.g. jar burial may indicate non-local origins.