Revelations of ancient head shape: Cranial modification in the Cuzco region of Peru, Early Horizon to Inca Imperial Period.

Objectives: Cranial vault modification (CVM), the intentional reshaping of the head, indicated group affiliation in prehistoric Andean South America. This study aims to analyze CVM data from the Cuzco region of Peru to illuminate patterns of early migration and settlement along with the later impact of the Inca Empire (AD 1438-1532) on the ethnic landscape.

Materials And Methods: 419 individuals from 10 archaeological sites spanning over 2300 years were assessed for CVM using morphological analysis.

Results: CVM patterns show distinct temporal attributes: the tabular type of modification appeared first and dominated the early sample (900 BC-AD 600), followed by an influx of unmodified crania during the Middle Horizon (AD 600-1000). The annular type appeared later during the Late Intermediate Period (AD 1000-1438). In the subsequent period of Inca imperialism, modification rates were higher at sites in the Cuzco countryside than in Cuzco city sites.

Discussion: The study results, combined with archaeological and ethnohistoric data, reveal the sociopolitical transformations that occurred prior to and during the rise of the Inca Empire. The influx of unmodified crania during the Middle Horizon resulted at least partly from Wari occupation, while the appearance of the annular type during the LIP points to migration into the area, possibly from the Lake Titicaca region. In the Inca Imperial Period, Inca individuals at Cuzco city sites refrained from modification as a sign of their ethnic identity, while modification patterns in the Cuzco countryside likely reflect state-coerced resettlement of different ethnic groups.