The condition and excavation of Shanidar Z

The skull overlaid the left upper limb and, below that, the thorax. The skull was completely flattened and all elements were delicate, crushed and friable, with some minor displacement (Figure 1). After careful excavation and in situ consolidation with the acrylic copolymer Paraloid B72 dissolved in acetone, most bones were lifted embedded in 46 small sediment blocks, following natural fissure lines (Figure 2). The blocks were wrapped in aluminium foil and placed in polyethylene bags. They were then cushioned with bubble wrap and put into rigid plastic boxes for air transport as hand luggage.

Figure 1.

The Shanidar Z skeletal remains under excavation in the east-facing section (a). Parallel angled white lines indicate the section left by the extraction of Shanidar 4 en bloc in 1960; the skull (detailed in b) is outlined in brown; the green line marks the area of the upper-limb bones (c), the orange line marks the area of the thorax (d). Scales: a) 100mm; b) 30mm; c) 100mm; d) 50mm (photographs by Graeme Barker).

Figure 2.

The lifting of consolidated bone and sediment blocks containing the Shanidar Z skeletal remains: a) layout of the blocks in which the skull was lifted; b) block 9 being lifted (photographs by Graeme Barker).

Documentation and conservation

The remains are on temporary loan to the University of Cambridge by the General Directorate of Antiquities and Heritage, Iraqi Kurdistan. All the packages were microCT-scanned while still wrapped in foil at the Cambridge Biotomography Centre using a Nikon XTEK H 225 ST MicroCT scanner (Figure 3). All were kept in a cold, stable environment until interventive conservation.

Figure 3.

MicroCT scanning process of the blocks (a & b) and a 3D rendering of the mandible (block 9) (c) (photographs by Emma Pomeroy).

First, ‘micro-excavation’ (similar to a full-scale excavation, but performed in the laboratory with small tools) was undertaken to remove the remaining sediment and to define each fragment. The entire process was documented through written descriptions, photographs, videos and a dedicated database. This documentation recorded the precise provenance of hundreds of fragments, each requiring cleaning and consolidation before they could be reassembled. Accurate data on the location and initial condition of each fragment will contribute to the taphonomic study of the cluster of individuals associated with Shanidar Z.

Due to the condition and fragility of the bone, interventive conservation techniques were employed, including cleaning, consolidation and reassembly. A summary of these procedures and the initial results are available elsewhere (López-Polín et al. Reference López-Polín2024). Figure 4 shows how one block of the skull was treated; a process that was repeated for the other blocks before elements were reassociated to reconstruct the skull (Figure 5). The techniques used included the removal of sediment with small manual tools (e.g. soft hairbrushes, bamboo skewers, scalpels and dental picks) and occasionally with some acetone and ethanol. The acrylic resin Paraloid B72 was used for multiple purposes: to consolidate the bones, as an adhesive and to adhere strips of lightweight fibreglass cloth (48g) to temporarily hold fragments in place and to reinforce the final bonds between some elements (Figure 5e & f; as described in López-Polín et al. Reference López-Polín2017). Paraloid B72 was chosen for all applications due to its multipurpose nature, ease of removal with solvent and long-term stability (Down Reference Down2015).

Figure 4.

Conservation of the skull, block 11: a) from left to right: 3D reconstruction of the side of the block exposed in the field, showing the right maxilla; photograph of the same block after initial opening of the package; the partially cleaned right maxilla, stabilised with fibreglass cloth strips (teeth labelled for reference: molar (M), premolars (P), canine (C) and incisor (I)); and the final prepared fragments and dentition of the right maxilla; b) the reverse side of the block, where the left maxilla was relatively well preserved; the partially cleaned left maxilla; and the final conserved left maxilla; c) outline of the Shanidar Z cranium in anterior view; shaded areas represent the fragments coming from block 11; the dashed line shows the axis along which the facial skeleton had folded in situ (photographs and illustration by Lucía López-Polín).

Figure 5.

Reconstruction of the Shanidar Z skull: numbers in (a) and (b) correspond to the blocks in Figure 2a; c and d) different views during the reconstruction process, in which fibreglass cloth strips impregnated with Paraloid B72 were used to temporarily reinforce joining pieces (e & f) (photographs by Lucía López-Polín).

The Shanidar Z bones are now clean and stable (Figure 6). Upper-limb elements are well reconstructed, though efforts are continuing for the highly fragmented thoracic bones. Further 3D and physical restoration of the skull will fill gaps between elements and correct minor distortions. The detailed conservation documentation will support future research. Accurate data on the location and initial condition of each fragment will contribute to understanding the morphology, behaviour and complex mortuary practices observed at this site.

Figure 6.

Elements of Shanidar Z after conservation: a) the skull; b) from left to right, the left scapula, metacarpals and manual phalanges, and radius; c) composite image of the ribs and vertebrae (photographs by Jamie Simmonds/BBC Studios (a) and Lucía López-Polín (b & c)).