How prehispanic foragers adjusted their foraging activities to plant cultivation is a question that drives much of the modern archaeological research. As a result, the spread of food-producing economies during the Late Prehispanic Period (c. 1500-360 BP) from Sierras of Córdoba, Argentina, has been recently defined as a dynamic sociocultural process, where a mixed foraging and cultivation economy was accompanied by a flexible land-use strategy. However, the economic organization has only been superficially assessed. Thus, the aim of this article is to present the study of faunal remains recovered during the excavation of the open-air site Boyo Paso 2 in order to provide primary data on the properties of the animal food remains left by late prehispanic people and the characteristics of site occupation.

The article presents the taxonomic study carried out on the Rheidae (Palaeognathae: Ratitae) faunal remains recovered in the open‐air archaeological site Boyo Paso 2 dated at approximately 1500–750 years BP (Sierras of Córdoba, Argentina). The study is focused on an adult proximal tarsometatarsus, a juvenile distal tarsometatarsus and 453 eggshell remains. The specimens were identified to its most specific level exploring and describing the diagnostic keys to species/genera level identification in modern reference collections. Two Rheidae species were identified: Rhea cf. R. americana and Rhea cf. R. pennata. However, most specimens were assigned to Rhea sp., including the tarsometatarsus remains. Taxonomic assignments indicate that even with the adoption of plant cultivation approximately 1.500 years BP, a broad spectrum foraging base played a key role for late prehispanic daily subsistence, increasing now the number of identified species added to the subsistence as the one not previously considered R. pennata. Its identification also suggests that the late prehispanic environment presented a higher biodiversity than at present, being the modern landscape a nonaccurate analogue of past conditions. It is concluded that achieving taxonomic identification to the most specific possible level becomes the fundamental pillars to assess the taxonomic diversity of human past subsistence as well as characterize the paleoenvironment, which mixed cultivation and foraging people interacted.