DISTRIBUCIÓN DE ALGUNAS ESPECIES DE MAMÍFEROS EN EL NORESTE DE LA PROVINCIA DE BUENOS AIRES DURANTE EL HOLOCENO

Abstract

DISTRIBUTION OF SOME MAMMALS SPECIES IN NORTHEASTERN BUENOS AIRES PROVINCE DURING THE HOLOCENE. - One hypothesis explaining the presence of species inherited from patagonic and central Dominion in the archaeological site Cañada de Rocha (north astern of Buenos Aires Province) is proposed. Environmental conditions more arid than present-day ones allowed the dispersión of species which do not live today in the area i.e. Lama glama guanicoe, Dolichotis patagonum and Canis (Pseudalopex) griseus. On the other hand, characteristic species from Subtropical Dominion (Blastocerus tlichotomus, Myocastor coypus and Hydrochoerus hydrochaeris) were absent or they were rare in Cañada de Rocha. However, these species were well registered in other archaeological sites of the area (La Maza I, Río Luján, Cañada Honda, Islas Las Lechiguanas, Campana), where the guanaco was not found or it was rare. A climatic oscillation may have modified the Faunistíc distribution. According to the Cañada de Rocha evidences, this site was occupied during an arid or semiarid climatic moment. Therefore, Cañada de Rocha may be diachronous in regard to the other sites, which must have been inhabited during humid climatic moments, similar to the present. The fauna obtained from Cañada de Rocha corresponds to "natíve" fauna; there were neither exotic fauna nor pleistocenic megamammals. Thus, the sediments which contain the faunistic and cultural elements are referred to the late Holocene. As there were no cultural elements indícating a Spanish contact, it can be inferred that Cañada de Rocha was inhabited before the XVIth century.