Early Homo Sapiens, and the native fauna extinction in the South America southern cone

CHICHKOYAN KARINA VANESA; BELINCHÓN MARGARITA; MARTINEZ- NAVARRO BIENVENIDO; LANATA JOSÉ LUIS

Congreso; XVII UISPP, Union Internationale des Sciences Préhistoriques et Protohistoriques; 2014

Dispersion is a survival Homo sapiens adaptive strategy to confront variable environmental stresses in different spaces. To compare how it developed in diverse paleoecologicalsettings is useful in order to understand how  this adaptive capacity was used in niche construction or modification. Resources to be exploit, competency with other species and passing through different climatic or geological barriers, are keys items in this question.America is an excellent opportunity to understand how dispersion was, in a landscape free from previous Hominini intervention. Focus emphases over the Pampean Region, Argentina, located at 36º S and 64 W. Homo sapiens would have created new niches of predation which would have allowed a fast dispersion timing.Taphonomical analysis was done in Rodrigo Botet Collection housed in the Museo de Ciencias Naturales de Valencia, Spain. This is the result of non-systematic excavationsdone at the north-eastern sector of the Pampas Region at the end of XIX century. Taphonomical history of these bones, species and squeletal parts can give informationabout agents involved in its burial, ecology of the native fauna and its habitat. This evidence can be related with human’s movements into the region at a coarse-grain level and thus understand how ecological relationship were constructed.11,466 elements were analysed, from which 10 elements, coming from different species, were detected showing different kinds of anthropic traces: four Mylodontidae bones, one Megatherium sp. rib and other two from Macrauchenia patachonica, three osteoderms withpentagonal and hexagonal shape, one from Glyptodontidaeand two from Eutatus.These native fauna developed during Pleistocene times and extinct just after humans colonized the region –except Eutatus, which survived until recent times. Because its size, they have low carnivore predation and consequently few avoidance behaviours. Also slow sexual maturity and low reproduction structure. In these populations, stressed by paleoenvironmental changes, sporadic human predation could have influenced its extinction.Dispersion into empty Hominini continents constituted a new ecological situation into human’s evolution. Therefore different dispersion dynamics can be compared and evaluated between first entries of humans in South America and Iberic Peninsula. While in Europeearly Homo sapiens dispersions could have taken at least 10.000 years, in America, the dispersion would have been fastest, between 3.000 or 2.000 years.This contrast with the general idea that fast dispersion is favored with previous knowledge. This should have happened in Europe, were previous hominid incursions happened since early Pleistocene. America, in return, was an uninhabited. Recognition of resources and geophorms should have taken longer time. Thus in contrast with what was proposed for America, in Iberic Peninsula, adaptation to previous Hominini existing niches andcompetition for resources would have delay dispersion in this space.