Insights into molar-incisor hypomineralisation in past populations: A call to anthropologists.

OBJECTIVE: Molar incisor hypomineralisation (MIH) is a developmental defect of enamel affecting the first permanent molars and often the incisors and affecting approximately 13% of the current population worldwide. Here, we aim to highlight potential differential diagnoses of MIH in archaeological collections (taphonomic discoloration, amelogenesis imperfecta, fluorosis, rachitic teeth, etc.). METHODS: Causative factors of dental discolourations are identified through a literature review. RESULTS: In an archaeological context, the sediments contained in the burial soil can lead to tooth discoloration. Taphonomic staining of the dentition may have a similar appearance to enamel hypomineralisation, and thus is a confounding factor that has the potential to cause miscalculation of the true prevalence of MIH within archaeological collections. Some rare medieval cases are reported in the modern literature but without microanalysis, misdiagnosis is possible. The aetiological factors of MIH are unknown but probably follow the multifactorial model involving systemic medical and genetic factors. CONCLUSIONS: Systematic detection and diagnosis of MIH during anthropological studies is therefore of great interest. SIGNIFICANCE: The hypotheses that only contemporary agents are causative factors of MIH could be refuted by the discovery of individuals living before medication or pollutants. The identification of MIH in a group of individuals also provides information regarding the health status of a population and reflects stress occurring during the period of mineralisation of the first permanent molars after secretion of the enamel matrix. LIMITATIONS: Taphonomic alterations of archaeological remains prevent MIH diagnosis. SUGGESTIONS FOR FUTURE RESEARCH: MIH diagnosis can be difficult in archaeological series and further non-destructive methods (microtomography, elemental analyses, etc.) are required.

Was it an axe or an adze? A cranial trauma case study from the Late Neolithic - Chalcolithic site of Cova Foradada (Calafell, Spain).

OBJECTIVE: To reconstruct the etiology of a perimortem injury observed on a Neolithic - Chalcolithic cranium (5060 - 4400 yrs cal. BP). MATERIALS: A cranium of an old adult male individual belonging to a collective burial from Cova Foradada site (Calafell, Tarragona, Spain). METHODS: The cranium was analyzed macroscopically and microscopically using micro-CT scan. RESULTS: The fracture on the right parietal bone presents characteristics of perimortem trauma. The morphology of the point of impact allows for the interpretation of this fracture as a result of impact by an object with a straight and sharp edge. In addition, the same cranium presents two healed antemortem injuries. CONCLUSIONS: The object that most likely caused the cranial fracture was a stone adze. The blow occurred from behind the individual, possibly by a right-handed attacker. SIGNIFICANCE: The potential to link cranial fractures with specific tools increases our understanding of interpersonal violence during the Neolithic. LIMITATIONS: It is not possible to infer if this cranial injury was related to a large-scale intergroup confrontation or an intragroup violent event. SUGGESTIONS FOR FURTHER RESEARCH: To investigate additional similar sites in the northeastern Iberian Peninsula to better characterize the fracture pattern caused by stone axes and adzes as well as other objects used as weapons during the Neolithic - Chalcolithic ages.

The Middle-to-Upper Paleolithic transition occupations from Cova Foradada (Calafell, NE Iberia).

The Middle-to-Upper Paleolithic transition in Europe covers the last millennia of Neanderthal life together with the appearance and expansion of Modern Human populations. Culturally, it is defined by the Late Middle Paleolithic succession, and by Early Upper Paleolithic complexes like the Châtelperronian (southwestern Europe), the Protoaurignacian, and the Early Aurignacian. Up to now, the southern boundary for the transition has been established as being situated between France and Iberia, in the Cantabrian façade and Pyrenees. According to this, the central and southern territories of Iberia are claimed to have been the refuge of the last Neanderthals for some additional millennia after they were replaced by anatomically Modern Humans on the rest of the continent. In this paper, we present the Middle-to-Upper Paleolithic transition sequence from Cova Foradada (Tarragona), a cave on the Catalan Mediterranean coastline. Archaeological research has documented a stratigraphic sequence containing a succession of very short-term occupations pertaining to the Châtelperronian, Early Aurignacian, and Gravettian. Cova Foradada therefore represents the southernmost Châtelperronian-Early Aurignacian sequence ever documented in Europe, significantly enlarging the territorial distribution of both cultures and providing an important geographical and chronological reference for understanding Neanderthal disappearance and the complete expansion of anatomically Modern Humans.

The genomic history of the Iberian Peninsula over the past 8000 years.

We assembled genome-wide data from 271 ancient Iberians, of whom 176 are from the largely unsampled period after 2000 BCE, thereby providing a high-resolution time transect of the Iberian Peninsula. We document high genetic substructure between northwestern and southeastern hunter-gatherers before the spread of farming. We reveal sporadic contacts between Iberia and North Africa by ~2500 BCE and, by ~2000 BCE, the replacement of 40% of Iberia's ancestry and nearly 100% of its Y-chromosomes by people with Steppe ancestry. We show that, in the Iron Age, Steppe ancestry had spread not only into Indo-European-speaking regions but also into non-Indo-European-speaking ones, and we reveal that present-day Basques are best described as a typical Iron Age population without the admixture events that later affected the rest of Iberia. Additionally, we document how, beginning at least in the Roman period, the ancestry of the peninsula was transformed by gene flow from North Africa and the eastern Mediterranean.