The missing crop: investigating the use of grasses at Els Trocs, a Neolithic cave site in the Pyrenees (1564 m asl)

The issue of resource exploitation, both plants and animals, by Neolithic communities has always attracted vast interest. In particular, resource exploitation at mountain cave sites is still being widely discussed. This paper explores the use of grass resources at the archaeological site of Els Trocs (Aragón, Spain), a Neolithic mountain site in the Pyrenees. The analysis of phytolith samples suggests that grasses growing in the surrounding of the site were widely used. The morphological assemblages identified, and their spatial distribution, indicate that wild grasses were probably used as floor spread. The integrated approach used in this study, combining phytolith, spherulite and micromorphological analyses, confirms this hypothesis. Furthermore, the analysis of phytolith assemblages and micromorphological traits indicate the seasonal occupation of the site, placing human frequentation at this location during late spring/early summer. Several studies have highlighted the presence of charred seeds of domesticated cereals in the archaeological record of mountain cave sites however, in many instances, whether these crops were cultivated near the sites or whether the grains were transported to the cave from the valley bottom remains under debate. This paper also contributes to this debate by showing that no crop-processing activities were taking place at the site.