New findings of Stephanorhinus kirchbergensis in Siberia

Abstract

New findings of Stephanorhinus kirchbergensis (Jäger, 1839) remains, obtained from the Asian part of Russia, are described. The material includes 39 specimens from 13 localities in West Siberia and East Siberia. It considerably expands the geographic distribution of this species of rhinoceros. A series of 11 mandibles from Siberia, including one juvenile individual with deciduous teeth, is described for the first time. We also present a large set of data on well-preserved postcranial remains. The morphology and sizes of mandibles, teeth, and postcranial remains of adult individuals of S. kirchbergensis from Siberia are similar to individuals of this species described from European localities. A series of upper teeth was subjected to mesowear analysis to assess the diet of S. kirchbergensis from West Siberia. The chemical composition (including stable isotopes) of the Siberian Stephanorhinus teeth is analyzed for the first time. Comparisons of Siberian S. kirchbergensis with European S. kirchbergensis and West Siberian Coelodonta antiquitatis broaden our understanding of the ecology, variability, and evolution of S. kirchbergensis under climatic changes in continental settings from the Middle to the Late Pleistocene. Despite small samples, we can suppose that S. kirchbergensis was widely distributed in Siberia.