Living on the river edge: The Tigre site (K-87) new data and implications for the initial colonization of the Uruguay River basin

Abstract This paper presents new data on the initial settlement of the southeastern region of South America, based on recent research conducted at the Tigre archaeological site (K87), located in the middle Uruguay River basin, near the Uruguayan border with Brazil and Argentina. The current archaeological excavations carried out in this open-air site confirmed that it is a multicomponent site. A new series of 20 radiocarbon dates refined the chronology of recurrent human occupations at this site during the late Pleistocene (13,260 cal BP), the Pleistocene-Holocene transition (12,920–11,750 cal BP), the early Holocene (11,300–9300 cal BP), and the late Holocene (1180 cal BP), demonstrating the strategic importance of this site during the prehistory of the region. In this paper, we describe the archaeological and stratigraphic contexts of the site, and analyze the artifact assemblage of the early components. Tigre points recovered from the archaeological excavations confirm that this is a Paleoamerican point design that circulated in the region between 12,000–11,100 cal BP. In addition, associated with these points, bifaces, fractured preforms and a type of asymmetric biface with a crescent/half moon shape were recovered. These “crescent artifacts” show a high standardization in form, size and knapping technique, which is described in this paper. Finally, we discuss the geographic distribution of the Tigre points, the blade technology present in the Uruguay River basin, the presence of prestige artifacts during the settlement, and the chronology of the “Umbu tradition” of southern Brazil in relation to the previous and recent data obtained in the Tigre site.