A multidisciplinary investigation into whether Andean caravans reached the southern lowlands of the Parana-Plata basin during pre-Columbian times

The expansion of llama caravans and the dispersal of domesticated camelids to extra-Andean regions is one of the key topics in South American archaeology, as it reflects the degree of connection between Andean societies and the surrounding lowland societies, as well as the extent of pre-Columbian pastoralism. One of the primary indicators of both processes is the presence of domesticated camelids in the archaeological record, particularly the llama (Lama glama). Based on somewhat ambiguous historical evidence, it has been suggested that llama caravanning may have reached the northern Pampean region and the southern Parana River valley from an unspecified time until historical times. While the archaeological sites in these two regions have abundant camelid remains that have thus far been identified as guanaco (Lama guanicoe), the possibility of misidentification due to the osteometric similarity between the domestic and wild camelids could mask the presence of llamas in the record, undermining evidence of this potential major expansion of llama caravans. To clarify this issue, we applied a multidisciplinary approach combining archaeological, isotopic, and paleogenomic analyses to determine the taxonomic status of camelids recovered from archaeological sites in both areas. Our findings demonstrate that all the individuals analyzed correspond to guanacos, whose survival extended into early historical times. There is no regional evidence to support the presence of llama caravanning or domesticated camelids in the northern Pampean region or the lower Parana River valley.