Small mammal remains recovered from two archaeological sites in northwestern Mendoza (Late Holocene, Argentina): Taxonomic composition, taphonomic issues and paleoenvironmental implications

We present the results of the extensive analysis on the taxonomic composition, the taphonomic characteristics, and the possible paleoenvironmental implications of the small mammal assemblages in two archaeological sites located in northwestern Mendoza, Argentina: Vaquería Gruta 1 and Rincón de los Helados. Such sites have been radiocarbon dated for the Late Holocene. The taphonomic characteristics of these remains, which were accumulated in VQG1 and RH by raptor Strigiformes and Falconiformes birds respectively, were analyzed by means of digestive corrosion on the bones, breakage patterns and relative abundances. In order to evaluate the changes in the composition between past and current assemblages, zooarchaeological and current small mammal assemblages were compared. The taxonomic composition and abundance of small mammals in archaeological assemblages suggest the existence of greater environmental heterogeneity than the current during the Late Holocene, as would suggest the presence of Reithrodon auritus and Octomys mimax, currently extinct species in the region. The co-occurrence of these species currently with allopatric distributions, lead us to consider these archaeological sets as non-analogue communities. In relation with the changes detected between past and current assemblages, some factors need to be considered. Among them, the relevance of the anthropic activities that have negatively affected the diversity, richness and abundance of flora and fauna since the XVI century, and the possible mixture of taxa due to the predation by owls in different altitudinal levels of vegetation.