Taphonomy of the Pilauco Site, Northwestern Chilean Patagonia

Pilauco shows two distinct layers containing remains of Pleistocene mammals (PB-7 and PB-8). The site is spatially divided into two sectors, East (45 m2) and West (27 m2). The current study is centered in the Western sector, where the majority of the materials come from layer PB-7 (%NISP = 92.5). Overall, this layer does not show signs of weathering, exhibiting instead trampling marks, and in a lesser quantity, large carnivore tooth marks. The fragmentation level is low, particularly for the fossils of Gomphotheriidae, for which most of the fractures occurred when the fossils were not fresh. No human marks of any kind were identified. The impact of these distinct factors in the formation of the record of PB-7 was evaluated using the available data and concluded in an in situ death of a gomphothere, to which would have been added anatomical elements of other taxa, redeposited coluvially and/or through vertical migration as a result of trampling. Carnivores would have been primarily responsible for the alteration and possibly subtraction of skeletal remains; as of now there is no evidence of human impact in this process. The materials recovered in PB-8 layer could also have been deposited by colluvial processes, although the sample is very small to discuss the taphonomic processes that have occurred in this layer.