Isotopic evidence for ceremonial provisioning of Late Bronze age khirigsuurs with horses from diverse geographic locales

Khirigsuurs are communal ritual and mortuary monuments that featured prominently on Late Bronze Age pastoralist landscapes of the Mongolian steppe through the mid-late second millennium to early first millennium cal BC. Khirigsuurs sustained ceremonies that legitimized the relationship between the deceased and the participants, facilitated the formation of new alliances, and emphasized integration and cohesion between mobile pastoralist communities through monument building, ritual horse slaughter, and feasting. Horses played a prominent role in ceremonial activities conducted at khirigsuurs, their heads and hooves regularly deposited in small stone satellite mounds as part of publically visible ceremonies associated with mortuary celebrations that simultaneously integrated mobile pastoralist communities. Here, strontium and oxygen isotopic analyses of sequentially sampled teeth of horses from khirigsuurs located in the Khanuy Valley, a major center of monumental activity situated north of the Khangai mountains in Mongolia, indicate horses from distant locales were ceremonially placed in khirigsuur satellite mounds, while patterned seasonal variation in carbon isotopes suggests horses were fodder provisioned during the winter months. These isotopic data suggest horses were well cared for, reflecting their status as a prestige animal, and were key to facilitating regionally integrative ceremonial activities conducted at khirigsuurs that brought together people from geographically distant mobile communities.