Isotopic evidence for the dietary evolution and shifting habitat of Equus ovodovi: a now-extinct equid from Late Holocene north China

Abstract

At some point in the past 3000 years, the equine species Equus ovodovi went extinct on the Eurasian steppe. Archaeological remains of the extinct species have been found and dated as late as 3500 B.P., suggesting interaction between E. ovodovi and human populations took place as recently as the Early Bronze Age. Yet the nature and degree of this interaction has gone largely unexplored. New evidence from north China helps cast light on this dynamic, illuminating the mystery of E. ovodovi extinction. Here we apply tools from archaeological science (stable carbon and nitrogen isotope analysis and AMS-14C dating) on ten bone samples of E. ovodovi recovered from two late Neolithic sites (Miaoliang and Muzhuzhuliang) on the Loess Plateau in northern Shaanxi, together with E. ovodovi data from the nearby large site of Shimao. Having combined our new stable isotopes with existing isotopic data from comparable sites in China and Russia, we employ a robust database of stable isotope values (n = 184) from human, animal and crop samples to piece together a plausible story of the long-term dietary transition of E. ovodovi in East Asia dating from approximately 45,000 to 3600 B.P. Uniquely 13C-enriched E. ovodovi dietary patterns at the three above-mentioned sites indicate the species likely occupied the periphery of the agricultural environment and operated in competition with domestic grazing animals. From roughly 4400 to 3600 B.P., E. ovodovi likely developed a degree of commensal behavior in this part of the north Shaanxi loess highland. Around 4000 B.P., with the consolidation of agropastoralism and subsequent widespread use of cattle and sheep / goat, the liminal nature of E. ovodovi, combined with the rise of elites at Shimao, may have inspired cultic-based hunting activities focused around this rare creature. Ritual activities and the emergence of a complex agro-pastoral economy, therefore, may have combined to drive E. ovodovi to regional extinction.