Instituto de Ciencias de la Tierra, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile.
Transdisciplinary Center for Quaternary research in the South of Chile, TAQUACh, Valdivia, Chile.
PLoS One. 2019 Apr 24;14(4):e0213572. doi: 10.1371/journal.pone.0213572. eCollection 2019.
The present study describes the discovery of a singular sedimentary structure corresponding to an ichnite that was excavated at the paleo-archaeological site Pilauco (Osorno, Chile). The trace fossil is associated with megafauna bones, plant material and unifacial lithic tools. Here we present a detailed analysis of the Pilauco ichnite and associated sedimentary structures, as well as new radiocarbon data. The ichnological analysis confidently assigns the trace to the ichnospecies Hominipes modernus-a hominoid footprint usually related to Homo sapiens. Some particular characteristics of the Pilauco trace include an elongated distal hallux, lateral digit impressions obliterated by the collapsed sediment, and sediment lumps inside and around the trace. In order to evaluate the origin of the ichnite, trackmaking experiments are performed on re-hydrated fossil bed sediments. The results demonstrate that a human agent could easily generate a footprint morphology equivalent to the sedimentary structure when walking on a saturated substrate. Based on the evidence, we conclude that the trackmaker might well have been a bare-footed adult human. This finding, along with the presence of lithic artifacts in the same sedimentary levels, might represent further evidence for a pre-Clovis South American colonization of northern Patagonia, as originally proposed for the nearby Monte Verde site.
本研究描述了在古考古遗址皮劳科（智利奥索尔诺）挖掘出的一种独特沉积结构的发现，该结构对应一种遗迹化石。该遗迹化石与巨型动物骨骼、植物材料和单面石器工具有关。在这里，我们对皮劳科遗迹化石和相关沉积结构进行了详细分析，并提供了新的放射性碳数据。通过遗迹化石分析，可以确定该足迹属于人足迹现代种（Hominipes modernus）——一种通常与智人相关的人科足迹。皮劳科足迹的一些特殊特征包括细长的远节趾骨、塌陷沉积物中消失的侧趾印痕，以及足迹内部和周围的沉积物块。为了评估遗迹化石的起源，我们对重新水合的化石床沉积物进行了足迹制作实验。结果表明，当人类在饱和的基底上行走时，很容易产生与沉积结构相当的足迹形态。根据这些证据，我们得出结论，造迹者很可能是赤足的成年人。这一发现，以及在同一沉积层中发现的石器工具，可能进一步证明了南美洲人在克洛维斯文化之前就已经在巴塔哥尼亚北部进行了殖民，这与附近蒙特韦德遗址的原始假设是一致的。
