A fossil shark tooth in early contexts of Cerro Casa de Piedra 7, southwest Patagonia, Argentina

Abstract

Casa de Piedra hill is located in one of the highest glacial lake basins of Patagonia (900 masl) (Figure 1). Belgrano and Burmeister lakes are the most important ones in this basin. Cerro Casa de Piedra 7 (CCP7) is one of several caves and rockshelters located on the northern side of the hill. CCP7 has a stratigraphic sequence which begins at the Pleistocene-Holocene transition. A fossil shark tooth was found in archaeological deposits dated to about 9000–9700 rcybp; it belongs to the genus Isurus (Elasmobranchii, Lamniformes, Isuridae). This species, unknown today in Santa Cruz marine coasts, lived in Patagonian seas during the Miocene epoch, at a time when there were sea ingressions. These ingressions flooded large areas within the present Patagonian territory and generated marine deposits in which abundant remains of extinct fauna (including shark teeth) can be found (Figure 1). In this paper, the recorded fossil tooth is described and its possible modification by human action is discussed.