The skeletons of Lauricocha: New data on old bones

The caves near Lake Lauricocha, Peru, were excavated between the late 1950s and mid-1960s and have since influenced the interpretation of early man in South America. Prior to the publication of this paper, the data used to interpret the age of this material was not based upon the human skeletons themselves, but were rather produced from the accompanying material, such as sediment, plant remains and animal bone. Radiocarbon dating in the 1960s was often not applied to human bones, as pre-treatment methods at that time were not as refined as at present and with conventional techniques, quite a lot of material had to be used. The development of AMS techniques requires much less material for analysis and sample preparation through collagen extraction means that radiocarbon dating of human bones is now possible and is a reliable method. As part of a wider project to analyse the DNA of the Lauricocha skeletons in order to elucidate migration patterns in Peru, we sampled 4 of the 11 skeletons for radiocarbon dating. This paper reports the results of this dating analysis. The results indicate that the skeletons are younger than interpreted from previously determined radiocarbon data on different material. However, this does not mean that the older analyses are wrong, and we review our findings in the light of this previous work to produce a new chronology for the site.