A Neanderthal from the Central Western Zagros, Iran. Structural reassessment of the Wezmeh 1 maxillary premolar.

Wezmeh Cave, in the Kermanshah region of Central Western Zagros, Iran, produced a Late Pleistocene faunal assemblage rich in carnivorans along with a human right maxillary premolar, Wezmeh 1, an unerupted tooth from an 8 ± 2 year-old individual. Uranium-series analyses of the fauna by alpha spectrometry provided age estimates between 70 and 11 ka. Crown dimensions place the tooth specimen at the upper limits of Late Pleistocene human ranges of variation. Wezmeh 1 metameric position (most likely a P3) remains uncertain and only its surficial morphology has been described so far. Accordingly, we used microfocus X-ray tomography (12.5 µm isotropic voxel size) to reassess the metameric position and taxonomic attribution of this specimen. We investigated its endostructural features and quantified crown tissue proportions. Topographic maps of enamel thickness (ET) distribution were also generated, and semilandmark-based geometric morphometric analyses of the enamel-dentine junction (EDJ) were performed. We compared Wezmeh 1 with unworn/slightly-moderately worn P3 and P4 of European Neanderthals, Middle Paleolithic modern humans from Qafzeh, an Upper Paleolithic premolar, and Holocene humans. The results confirm that Wezmeh 1 represents a P3. Based on its internal conformation and especially EDJ shape, Wezmeh 1 aligns closely with Neanderthals and is distinct from the fossil and extant modern human pattern of our comparative samples. Wezmeh 1 is thus the first direct evidence of Neanderthal presence on the western margin of the Iranian Plateau.

Early Neolithic genomes from the eastern Fertile Crescent.

We sequenced Early Neolithic genomes from the Zagros region of Iran (eastern Fertile Crescent), where some of the earliest evidence for farming is found, and identify a previously uncharacterized population that is neither ancestral to the first European farmers nor has contributed substantially to the ancestry of modern Europeans. These people are estimated to have separated from Early Neolithic farmers in Anatolia some 46,000 to 77,000 years ago and show affinities to modern-day Pakistani and Afghan populations, but particularly to Iranian Zoroastrians. We conclude that multiple, genetically differentiated hunter-gatherer populations adopted farming in southwestern Asia, that components of pre-Neolithic population structure were preserved as farming spread into neighboring regions, and that the Zagros region was the cradle of eastward expansion.

Late Pleistocene human remains from Wezmeh Cave, western Iran.

Paleontological analysis of remains from Wezmeh Cave in western Iran have yielded a Holocene Chalcolithic archeological assemblage, a rich Late Pleistocene carnivore faunal assemblage, and an isolated unerupted human maxillary premolar (P(3) or possibly P(4)). Species representation and U-series dating of faunal teeth place the carnivore assemblage during oxygen isotope stages (OIS) 3 and 2, and noninvasive gamma spectrometry dating of the human premolar places it at least as old as early OIS 2. The human premolar crown morphology is not diagnostic of late archaic versus early modern human affinities, but its buccolingual diameter places it at the upper limits of Late Pleistocene human P(3) and P(4) dimensions and separate from a terminal Pleistocene regional sample. Wezmeh Cave therefore provides additional Paleolithic human remains from the Zagros Mountains and further documents Late Pleistocene human association with otherwise carnivore-dominated cave assemblages.