Iron Age nomads of southern Siberia in craniofacial perspective

Abstract

This study quantifies the population history of Iron Age nomads of southern Siberia by analyzing craniofacial diversity among contemporaneous Bronze and Iron Age (7th–2nd centuries BC) groups and compares them to a larger geographic sample of modern Siberian and Central Asian populations. In our analyses, we focus on peoples of the Tagar and Pazyryk cultures, and Iron Age peoples of the Tuva region. Twenty-six cranial landmarks of the vault and facial skeleton were analyzed on a total of 461 ancient and modern individuals using geometric morphometric techniques. Male and female crania were separated to assess potential sex-biased migration patterns. We explore southern Siberian population history by including Turkic-speaking peoples, a Xiongnu Iron Age sample from Mongolia, and a Bronze Age sample from Xinjiang. Results show that male Pazyryk cluster closer to Iron Age Tuvans, while Pazyryk females are more isolated. Conversely, Tagar males seem more isolated, while Tagar females cluster amongst an Early Iron Age southern Siberian sample. When additional modern Siberian samples are included, Tagar and Pazyryk males cluster more closely with each other than females, suggesting possible sex-biased migration amongst different Siberian groups. This is evident in modern female Tuva, who cluster with modern female Kalmyk, while modern Tuvan males do not. Male and female Iron Age Tuvans are not closely related to modern Tuvan peoples living in the region today, resulting from the influx of the Xiongnu beginning in the Late Iron Age. Both male and female Pazyryk and Tagar crania appear more similar to Central Asia groups, especially the Kazakh and Uzbek samples. However, there is evidence that Tagar females have a common origin with the Yakut, a modern nomadic population that resides in northeastern Siberia. These results would suggest variable genetic contributions for both sexes from Central and East Asia.