Differentiation of south american camelids foraging areas through phytolith, pollen, and plant remains analysis of modern feces

Abstract

Paleoecological studies through the multiproxy analysis of coprolites provide information about the diet, vegetation and ancient habitats. Relationships between humans and camelids date back to the end of the Pleistocene in Patagonia, Argentina. Different archeological sites in the Pueyrredón–Posadas–Salitroso Lacustrine System contain camelid coprolites and evidences of human occupation since 8,600 yrs cal. BP. The environmental changes and lake-level fluctuations in the area have influenced the landscape and resource availability. Actualistic studies are crucial for building reference models to enhance paleoecological interpretations of Holocene coprolites in Patagonia. The aim of this study was to identify and differentiate the feeding areas of Lama guanicoe (‘guanacos’) through the analysis of phytoliths, pollen, and plant remains found in modern feces. The samples were collected in the shrub-grass steppe of Cueva Milodón Norte 1 area (CMN1) and the shrub steppe of Salitroso lake area (SAL). Routine protocols were used for multiproxy analysis of the feces. This analysis provided different levels of taxonomic resolution, achieved by each proxy, in the identification of the representative plants from each environment. For instance, Fabaceae, Colliguaja sp. and Poa ligularis in feces of CMN1, and Chenopodiaceae, Nassauvia sp., and Pappostipa humilis in feces of SAL, among others. Principal component analyses allowed for the differentiation of feces from SAL and CMN1. This work highlights the multiproxy approach in the study of modern feces. Also, these results emphasize the importance of establishing reference patterns for the identification and interpretation of paleodiet and paleoenvironment of herbivores.