The Bell Beaker multiple burial pit of La Atalayuela (La Rioja, Spain): stable isotope insights into diet, identity and mortuary practices in Chalcolithic Iberia.

La Atalayuela is a Middle Chalcolithic (ca. 2900-2500 cal BC) multiple burial pit located in the mid-upper Ebro Valley (north-central Iberia) where a large number of individuals (more than 70) were inhumed. The site shows an apparently constrained period of funerary use, which includes the probable simultaneous burial of a large proportion of the deceased. This offers an outstanding opportunity to investigate the lifeways and identity of the members of what was presumably a single community living and interring their dead at the very beginnings of the Bell Beaker culture in the region. Here, we present stable carbon and nitrogen isotope values on bone collagen from 46 humans. While the overall results are consistent with diets focused on C-3 plants and terrestrial animal resources, as would be expected, the variability still demonstrates some interesting patterning. Thus, there is a significant differentiation in delta C-13 values between burial context base (the earliest funerary use identified, interpreted as a 'house of the dead') and the following context a2 (interpreted as a mass grave), supporting the existence of potentially distinct funerary uses. Remains from the vestibule (a structure to the south of the pit interpreted as entrance), whose carbon isotope values also differ from those of a2, have been tentatively associated with base and interpreted as a result of potential bone arrangements prior to the mass interment. Statistically significant age- and sex-related isotopic differences are also identified, which allow social insights, such as possible differential access by children and women to certain food sources, which may in turn reflect a possible sexual division of labour. The results are set in the context of other Late Prehistoric Iberian funerary and isotopic data.