In last month’s ‘Science Notes’, we discussed evidence that suggested the Neolithic saw an increase in violence, potentially linked to increasing social and economic stratification (see CA 397). Here we will continue on this theme, highlighting a recent study that aimed to determine whether stone axes and adzes – common tools during the Neolithic – were also used as weapons. The researchers did this by recreating probable injury patterns on the skull and seeing if these matched injuries found in the archaeological record.
In modern forensics, synthetic crania – polyurethane spheres made by SYNBONE, which approximate the properties of a human cranium – are often used to test ballistic wounds. SYNBONE spheres have also been used in archaeological experiments, though, to determine the probable injury patterns that past weapons may have made. For the Neolithic, experiments have been carried out using blunt weapons such as clubs, but, until recently, no one had tested the probable fracture patterns caused by stone axes and adzes which, based on their design, are thought to have produced very specific – and hence recognisable – fracture patterns.
During the research, Miguel Ángel Moreno-Ibáñez – from the Catalan Institute of Human Palaeoecology and Social Evolution (IPHES) and Universitat Rovira i Virgili in Tarragona, Spain – used seven SYNBONE spheres covered in rubber to mimic skin. They were also filled with ballistic gelatin to simulate the brain and other soft tissue of the cranium. The spheres were mounted on a movable ‘neck’ (in fact, a flexible hosepipe) that allowed them to move in a similar way to a real human head. Each sphere was then struck with a recreated Neolithic weapon: three with a stone axe and four with a stone adze, both of which were made using prehistoric methods and materials. The experiment was conducted in collaboration with the School of History, Classics, and Archaeology at the University of Edinburgh.
The results showed that the axe and adze created slightly different fracture patterns. Two of the axe hits produced deep, penetrating fractures that were vaguely teardrop in outline, with the aspect closest to the attacker having a more rounded shape – as this is where the axe penetrated the deepest – but a more pointed aspect on the posterior of the wound, furthest from the attacker. Both hits produced fracture lines that radiated out from the wound, as well as internal ‘bevelling’ where flakes of bone broke away from the impact point on the inside of the cranium. The third hit by the axe was slightly different as it was carried out at almost a 45° angle. This produced the same sub-triangular fracture outline, but it did not fully penetrate the inside of the cranium, instead leaving attached fragments of bone pointing inwards. There were no radiating fracture lines in this case.
As for the adze, in three of the strikes the resulting fracture featured one straight side, which was the point of impact, and one convex side, which was caused by the dispersive force following the direction of the blow. This meant that the area that had the greatest destruction indicated the direction of the strike. Radiating fracture lines were also seen, but were much smaller than those caused by the axe. Additionally, as with the axe wounds, there was internal ‘bevelling’ and adhered, inward-penetrating bone fragments, but, instead of being on both sides of the wound, they were mostly associated with the direction of the blow.
The last adze strike, at first glance, appeared similar to the others, but was actually markedly different as, unlike the other hits, it was carried out from a great height. This meant that the adze struck the bone at a more-than 90° angle, creating a mirror image to the others with the straight side of the fracture in a posterior position and the convex side to the front. This means that, without context, it would seem as if this cranium had been struck from behind, when in fact it was struck from the same position as all the others: face to face. This difference indicates that, although we may be able to identify possible weapons and attack patterns, this can never be definitive, particularly considering the many variables associated with an actual assault.
What this research has shown, however, is that many fracture patterns found at the early Neolithic massacre site of Talheim, in modern-day Germany, may have been caused by adzes, and that an adze could also have caused the injury inflicted on the individual who was buried in the Cova Foradada in Calafell, Spain – all of which exhibit wounds with one clear straight side and one convex one, with internal bevelling on the convex inside edge.
The Journal of Archaeological Science recently published the full results: https://doi.org/10.1016/j.jas.2023.105739.