Analysis of ancient DNA from South American rhea bones: Implications for zooarchaeology and biogeography

Abstract

Rheas have been an important food source to human communities in South America, providing meat and especially eggs, and thus playing a crucial role in the development of South American societies. Two extant species currently exist: Rhea americana (greater rhea) and Rhea pennata (lesser rhea). Both species occupy distinct geographic ranges except for an overlapping area in Argentina to the immediate north of Río Negro, in the southwestern Pampa region. Distinguishing these two species in the archaeological record is difficult due to overlap in osteological morphology and the presence of few diagnostic skeletal identification criteria. This is problematic when studying the ancient geographic distributions of rheas and the roles they played in past societies. The aim of this paper is, thus, to assess whether or not genetic data can be used to differentiate between the two species and to confirm identifications of previously analyzed archaeological specimens. This is the first genetic study conducted on ancient rheas, and this approach will become a crucial tool for identifying rhea remains from other archaeological sites to study the roles they played in diets of past peoples. Our research also addresses current conservation issues by comparing the past and modern distributions of these birds, which can help provide information for future policies for the conservation of these birds.