A constant and intense debate in South American archaeology stands on the origin and patterns of food production of ancient populations and the correlation of both aspects with demographic growth and social complexity. Some studies associated population growth with the shift from foraging to agricultural practices in hotspots on the continent. This association has been confronted by a number of studies performed in recent years that reconstructed dietary patterns for several tropical and subtropical areas of eastern South America. However, there is still a lack of information on the diet for Late Holocene populations in the wetlands of the Pampa Biome. In order to access the paleodiet of earthen-mound builders from southern Patos Lagoon (Brazil), this study combined bulk collagen stable carbon and nitrogen isotopes analysis of faunal and human remains with Bayesian Stable Isotope Mixing Models. The paleodiet of 20 human and one dog remains from six sites was reconstructed. The Bayesian mixing model on collagen δ¹³C and δ¹⁵N values revealed variable subsistence strategies with high consumption of marine/estuarine protein for some individuals. Other individuals’ diets relied on terrestrial/freshwater resources as protein sources. In southeastern South America, such patterns reinforce the resource-rich aquatic environment as a facilitator for the endurance of mixed economies. In addition, our results suggest that the Patos Lagoon surroundings was a “hub of interactivity” characterised by a remarkable intra-site dietary variability.

南美考古学一直在激烈争论古代人口的食物生产起源和模式，以及这两个方面与人口增长和社会复杂性的相关性。一些研究将人口增长与非洲大陆热点地区从觅食转向农业实践联系起来。近年来进行的许多研究都面临着这种关联，这些研究重建了南美洲东部几个热带和亚热带地区的饮食模式。然而，仍然缺乏关于潘帕生物群落湿地中全新世晚期种群饮食的信息。为了访问来自帕托斯泻湖（巴西）南部的土丘建造者的古生物，本研究将动物和人类遗骸的大量胶原蛋白稳定碳和氮同位素分析与贝叶斯稳定同位素混合模型相结合。重建了来自六个地点的 20 个人和 1 只狗的古饮食结构。胶原蛋白贝叶斯混合模型δ ¹³ C 和δ ¹⁵ N 值揭示了一些个体高消耗海洋/河口蛋白质的可变生存策略。其他人的饮食依赖陆地/淡水资源作为蛋白质来源。在南美洲东南部，这种模式强化了资源丰富的水生环境，促进了混合经济的持久性。此外，我们的研究结果表明，帕托斯泻湖周围环境是一个“互动中心”，其特点是场内饮食差异显着。