Journal of Archaeological Science: Reports 34 (2020) 102620 Available online 19 October 2020 2352-409X/© 2020 Elsevier Ltd. All rights reserved. More carnivorous than vegetarian: Isotopic perspectives on human diets in Late Holocene northwestern Patagonia Adolfo F. Gil a, * , Andrew Ugan b , Gustavo A. Neme a a Instituto de Evoluci´ on, Ecología Hist´ orica y Ambiente-IDEVEA (CONICET & UTN), Av. Gral. J. J. Urquiza 314, 5600 San Rafael, Mendoza, Argentina b Far Western Anthropological Research Group, Davis, CA, USA A R T I C L E INFO Keywords: Human diet Patagonia Small faunas Late holocene Stable isotope Intensifcation ABSTRACT This paper reevaluates the signifcance of plants and animals in Late Holocene human diets of northwestern Patagonia. The area was occupied by hunter-gatherers who, despite the presence of nearby agricultural pop- ulations, did not abandon their emphasis on the exploitation of wild resources. Combining new and previously published stable isotope data from human bone collagen ( 13 C, 15 N; n = 53) and bone carbonate ( 13 C; n = 21) we use Bayesian mixing models to estimate human trophic levels, the relative proportion of various plant and animal resources in prehistoric diets, and how geographic variation in those values relates to environmental structure. The results of that analysis demonstrate a high reliance on meat rather than plants. Our results call attention to an apparently heavy reliance on small game prehistorically, which differs from all previous analyses. Maize, in contrast, was non signifcant. This research highlights the signifcance of exploring spatially meaningful units of analysis and the need to incorporate a set of ecologically diverse baseline isotope data in order to understand trends and variation in human resource use. 1. Introduction Central-western Argentina represents a culturally and environmen- tally heterogeneous region marking the southern boundary of pre- hispanic farming in South America. Stretching from northern Neuqu´ en and Mendoza north through San Juan and east into La Pampa (Fig. 1), the area contains evidence for a mosaic of human subsistence strategies, ranging from full-time farmers to full-time hunters and gatherers (Gambier, 2000; Lagiglia, 2001). The area north of the Atuel River, in central Mendoza, was occupied by populations using domesticated plants starting approximately 2000 years BP (Lagiglia, 1982; Gil et al., 2014a, 2018). South of this river hunters and gatherers continued until historic times, with little evidence for the incorporation of domesticates despite their use among nearby groups (Gil and Neme, 2013; Gil et al., 2018). Differences in farming versus hunting and gathering refect differ- ences in the availability and distribution of food in local habitats, the ways in which resources were exploited, and human population den- sities and resource pressure (Binford, 2001; Johnson et al., 2015). Bin- ford (2001) indicates that in most settings, terrestrial animal dependence is only possible at low population densities, which are places where residential mobility is relatively unrestricted. When people live at high population densities, residential mobility is severely con- strained and subsistence tactics intensify, primarily by increasing the contributions of plants and aquatic resources (Johnson et al., 2015). Given that Central-western Argentina is an arid environment with few perennial water sources, we would expect hunter–gatherers there to focus their efforts on plants if forced to intensify (Johnson et al., 2015), incorporating domestic plants as a last step in this process. There is mounting evidence for just such a pattern in the areas north of the Atuel River, beginning 3000 to 4,000 years ago (Lagiglia, 1982; Gil et al., 2011, 2014a, 2014b; Neme, 2009; L´ opez et al., 2019). Although there has been less work done in the areas immediately south of the Atuel River (southern Mendoza, northern Neuqu´ en and west La Pampa collectively referred to here as “Northwestern Patagonia”), the general picture there has been one of continued reliance on diverse terrestrial faunas up until contact (Otaola et al., 2015; Rindel, 2017), with a focus on the consumption of large animals such as guanacos (Lama guanicoe). A recent multi-proxy analysis of Northwest Patagonian population dynamics indicate that the initial increase in population size occurred 2000 years before the frst evidence of sites with a high con- centration of burials and grinding stones, which are found in the archaeological record around 4000–4500 years ago (Perez et al., 2009). Similarly, the frst record of pottery use is dated ca. 1900 years B.P., a * Corresponding author. Contents lists available at ScienceDirect Journal of Archaeological Science: Reports journal homepage: www.elsevier.com/locate/jasrep https://doi.org/10.1016/j.jasrep.2020.102620 Received 11 November 2019; Received in revised form 5 October 2020; Accepted 6 October 2020