Thursday, May 28, 2015
Lethal Interpersonal Violence in the Middle Pleistocene
Evidence of interpersonal violence has been documented previously in Pleistocene members of the genus Homo, but only very rarely has this been posited as the possible manner of death. Here we report the earliest evidence of lethal interpersonal violence in the hominin fossil record. Cranium 17 recovered from the Sima de los Huesos Middle Pleistocene site shows two clear perimortem depression fractures on the frontal bone, interpreted as being produced by two episodes of localized blunt force trauma. The type of injuries, their location, the strong similarity of the fractures in shape and size, and the different orientations and implied trajectories of the two fractures suggest they were produced with the same object in face-to-face interpersonal conflict. Given that either of the two traumatic events was likely lethal, the presence of multiple blows implies an intention to kill. This finding shows that the lethal interpersonal violence is an ancient human behavior and has important implications for the accumulation of bodies at the site, supporting an anthropic origin. PLOS
Fig 1. Stratigraphy of the Sima de los Huesos site (modified from Arsuaga et al. ).
The hominin bones were recovered in Lithostratigraphic Unit 6 (LU-6) dated to c. 430ka . This unit is composed of pure red clays, filtering into the conduit system from overlying soils with little or no lateral transport, and very low velocity of sedimentation (decantation by dripping water) . The figure also shows a detailed image of Cr-17 during its excavation at the site. Note the pure red clay that covers the cranial bones (partially cleaned in situ to enhance visualization) and the typical in situ postmortem (fossil diagenetic) fractures of the cranial vault. Photo credit: Javier Trueba (Madrid Scientific Films).
The skull in question was found at a site in Spain called Sima de los Huesos, or the Pit of the Bones, and it contained remains of 28 individuals. Quam said their presence there was intentional. "The only explanation that we have that can not be rejected is the idea that the human bodies arrived at this place by other humans," Quam told NPR. npr