Anthropologists report they have found the oldest documented site of a mass killing in what is now Croatia. Findings from the 6,200-year-old massacre were published in PLOS ONE earlier this month.
Previous research has identified ancient massacre sites of men in battle, as well as mass graves containing the remains of a targeted family. To verify the uniqueness of this grave as neither of those options—rather, a “traditional massacre”—the researchers performed a genome-wide analysis on nearly all of the victims.
The mass burial site comprises a small pit, about 2 meters in diameter and 1 in depth, that contained the commingled, still-articulated human skeletal remains of 41 individuals. The research team was able to generate genome-wide data from 38 of the 41 individuals. (The genotypes have been deposited for public access to the Reich lab website for those interested.)
According to the paper, uniparental markers identified 30 different mitochondrial lineages and six different Y-chromosome lineages, suggesting the victims belonged to a large community with a diverse pool of female lineages. Only 11 of the 38 were found to be closely related (3rd degree or closer), with 70% of the analyzed individuals not having a close kin among the deceased. This led researchers to conclude that the violent attack targeted a small subset of individuals in a community composed of many family groups, rather than the targeted killing of a specific family unit.
Additionally, there was no sex bias to the murders, as the number of males and females were almost equal, ruling out a battle scene or the targeting of a single gender. The victims were also found to be a wide range of ages, lending credence to the violent attack theory.
The DNA analysis also revealed the ancestry of the victims was homogeneous, making it unlikely the massacre was linked to the arrival of new genetic ancestry.
"This is the oldest known case of indiscriminate, mass killing that we know of," said James Ahern, an author on the paper and a University of Wyoming anthropology professor. "In some ways, it goes against the conventional wisdom about early agriculturalists—the Neolithic and Eneolithic—who have long been thought to have lived in small villages or herding groups.”
Analysis of the skeletal remains also revealed perimortem cranial injuries in 13 of the 41 individuals—six children, three adult males and four adult females—located mostly on the side or the back of the head.
"Although we do not have evidence on the cause of death for the other individuals, their deaths were almost certainly violent," said Ahern. "Multiple radiocarbon dates, as well as the sedimentology of the burial, all indicate a single burial event. A majority of violent deaths do not leave clear evidence of trauma in the preserved skeletal remains. Individuals could have been strangled, bludgeoned, cut or stabbed in soft-tissue areas or in manners that did not damage underlying bones."
Data in the study reveal how organized violence in this period could be indiscriminate, just as indiscriminate killings have been an important feature of life in historic and modern times. Future research will include the study and analysis of additional massacre sites to determine the prevalence of this pattern of ancient violence.
"Perhaps, because of the long history of human violence and warfare and its contemporary relevance, the public is engaged by the sort of narrative about the deep human past that we've been able to recreate through our scientific research," said Ahern. "Furthermore, DNA, heredity and human ancestry are issues that touch everyone's lives.”
Photo: The upper layers of the Potočani mass burial shows numerous commingled skeletons. Credit: Jacqueline Balen, Archaeological Museum of Zagreb