Taphonomic Approach to the Interpretation of Isolated Human Skulls: Distinguishing Natural from Intentional Deposition

The human cranium is probably the most common single anatomical element manipulated after the death of the individual. However, it is not uncommon to find isolated crania for which it is difficult to unequivocally determine the nature of the deposition, either intentional or natural. In order to establish whether naturally deposited and intentionally deposited skulls are characterised by different taphonomic patterns, we evaluated the state of preservation of 75 isolated crania (68 naturally deposited and 7 intentionally deposited) from sites in Africa, Europe, Near East and Asia, from approximately 2 million to 20,000 years BP. As a comparative reference, we evaluated the preservation pattern of further 101 skulls from individuals buried in primary deposition at two cemeteries. Finally, to determine whether the breakage pattern of skull-cups (skulls intentionally modified and manufactured into bowls) mimics a natural skull breakage, we analysed the preservation pattern of 19 skull-cups from archaeological and ethnographic contexts. Preservation and breakage patterns were evaluated using the Zonation method and the Landmark method. Results suggest that the intentionally deposited skulls have a pattern of preservation similar to the skulls found in cemeteries, and for both these categories, skulls were generally better preserved than naturally deposited skulls. The natural breakage pattern of isolated skulls also significantly differs from the breakage pattern of skulls modified into skull-cups, suggesting that it is unlikely that skull-cups were fashioned in a manner that imitates natural breakage patterns.