Sperm-whale V-perforated buttons from Galeria da Cisterna (Almonda Karst System, Torres Novas, Portugal)*

Abstract

During excavation of the prehistoric necropolis of Galeria da Cisterna in 1988-1989, the remains of several individuals were recorded. The direct dating of four attests to use of the cave for funerary purposes during Beaker times. Whilst no Beaker pottery was found, a small fragment of a golden spiral and a set of V-perforated ivory buttons are diagnostic of the period. These items can be securely associated with the human remains dated to the corresponding time range. Visual inspection identified sperm whale ivory as the rawmaterial the buttons were made of, which density measurements confirmed. This indicator was chosen because it is non-destructive and discriminates well between the different types of ivory found in the Chalcolithic of Iberia. The average obtained for the 13 specimens from Galeria da Cisterna is 2.32 ± 0.12, well outside the range for elephant and hippopotamus ivories and consistent with the average value (2.2) for sperm-whale ivory published by Schuhmacher et al. (2013). The gold object was most likely made from regional sources. These data reflect on the wide intra-regional networks in operation during the Chalcolithic of the Lisbon peninsula. They also suggest that extra-regional exchange was rather more limited, as the golds of the Alentejo sites usually are of a distinct composition and sperm-whale has never been identified among their ivories (which are of North-African elephant, a rare occurrence in the Lisbon peninsula).