Holes in the Head. Double cranial surgery on an individual from the Chalcolithic burial site of Camino del Molino (SE Spain).

OBJECTIVE: This article analyses new prehistoric evidence of trepanation from a collective burial site in the south-eastern Iberian Peninsula. MATERIALS: The trepanned individual was documented in the Chalcolithic burial site of Camino del Molino, where 1348 individuals (30.7 % non-adults and 69.3 % adults) were deposited in two contiguous funerary phases, making it a reference site for the knowledge of Recent Prehistoric populations. METHODS: The individual has been sexed using traditional anthropological methods and ancient DNA. C14 dating has also been obtained. The lesion has been analysed macroscopically and microscopically using SEM. RESULTS: The skull under study belonged to an adult female deposited in the second burial phase (2566-2239 years cal BCE). It exhibits in the anterior region of the right temporal fossa two contiguous and partially overlapping holes that correspond to two trepanations performed using the scraping technique. CONCLUSIONS: It is a double cranial trepanation with signs of bone remodelling suggesting survival from surgery. No pathological signs were identified potentially associated with the intervention. SIGNIFICANCE: This is the second case of surgical interventions in the geographical area of study and one of the few evidences of this practice in women during prehistoric times. LIMITATIONS: So far only the articulated skeletons from this burial have been thoroughly analysed. SUGGESTIONS FOR FURTHER RESEARCH: Further intensive review of skull collection is advised to learn more about these surgical interventions in Copper Age and to go deeper into the causes that motivated their execution.

Understanding the microbial biogeography of ancient human dentitions to guide study design and interpretation.

The oral cavity is a heterogeneous environment, varying in factors such as pH, oxygen levels, and salivary flow. These factors affect the microbial community composition and distribution of species in dental plaque, but it is not known how well these patterns are reflected in archaeological dental calculus. In most archaeological studies, a single sample of dental calculus is studied per individual and is assumed to represent the entire oral cavity. However, it is not known if this sampling strategy introduces biases into studies of the ancient oral microbiome. Here, we present the results of a shotgun metagenomic study of a dense sampling of dental calculus from four Chalcolithic individuals from the southeast Iberian peninsula (ca. 4500-5000 BP). Interindividual differences in microbial composition are found to be much larger than intraindividual differences, indicating that a single sample can indeed represent an individual in most cases. However, there are minor spatial patterns in species distribution within the oral cavity that should be taken into account when designing a study or interpreting results. Finally, we show that plant DNA identified in the samples is likely of postmortem origin, demonstrating the importance of including environmental controls or additional lines of biomolecular evidence in dietary interpretations.

Hyaenas and early humans in the latest Early Pleistocene of South-Western Europe.

Throughout the Pleistocene, early humans and carnivores frequented caves and large rock-shelters, usually generating bone accumulations. The well-preserved late Early Pleistocene sedimentary sequence at Cueva Negra del Estrecho del Río Quípar (CNERQ) has provided substantial evidence concerning the behavioural and adaptive skills of early humans in Western Europe, such as butchery practices, lithic technology or tending fire, whilst also bearing witness to the bone-altering activities of carnivores. Recent fieldwork has allowed the re-examination of the spatial and taphonomical nature of the macrofaunal assemblage from the upper layers of Complex 2. These layers are somewhat different from most of the underlying sequence, in showing quite a high representation of cranial and post-cranial bones of large mammals, including several Megaloceros carthaginiensis antlers. The presence of Crocuta sp. at Cueva Negra represents one of the earliest instances of this genus in Western Eurasia. Identification of several juvenile Crocuta sp. remains alongside coprolites and bones with carnivore damage, indicates sporadical hyaenid denning activity. Furthermore, the presence of bones with percussion and cut-marks near to several hammerstones suggests a clear albeit limited anthropogenic input. We interpret the available taphonomical and spatial evidence from these layers as reflecting a multi-patterned palimpsest, likely representing the non-simultaneous and short-lived co-existence of hyaenas, humans, and other small carnivores in the Cueva Negra palaeolandscape during the final phase of sedimentation preserved at the site.

Genomic transformation and social organization during the Copper Age-Bronze Age transition in southern Iberia.

The emerging Bronze Age (BA) of southeastern Iberia saw marked social changes. Late Copper Age (CA) settlements were abandoned in favor of hilltop sites, and collective graves were largely replaced by single or double burials with often distinctive grave goods indirectly reflecting a hierarchical social organization, as exemplified by the BA El Argar group. We explored this transition from a genomic viewpoint by tripling the amount of data available for this period. Concomitant with the rise of El Argar starting ~2200 cal BCE, we observe a complete turnover of Y-chromosome lineages along with the arrival of steppe-related ancestry. This pattern is consistent with a founder effect in male lineages, supported by our finding that males shared more relatives at sites than females. However, simple two-source models do not find support in some El Argar groups, suggesting additional genetic contributions from the Mediterranean that could predate the BA.