On The Time And Environment Of Stephanorhinus Kirchbergensis Jager 1839 (Mammalia, Rhinoceratidae) In The Altais And Northeastern Russia

Merck's rhino (Stephanorhinus kirchbergensis (Jager 1839)), one of the extinct members of the Pleistocene megafauna, is scarce in Russia's geological record. According to the previous research paradigm, that large rhinoceros inhabited forest environments during interglacials, consumed mostly branch- and leaf-containing food, and went extinct across most of its range during the Middle Pleistocene, still persisting in southern Si-beria until the Late Pleistocene. No direct evidence of this species associated with Late Pleistocene deposits and based on 14C dating has hitherto been obtained in Russia. Our studies on the mandible of Merck's rhino from the South of western Siberia confirm that the species was present in the Altai region until the second half of the Late Pleistocene (MIS3), but much later than previously thought, until about 40000 years before present. Tooth enamel microwear shows that this rhino ate branches and leaves of various trees and shrubs. Merck's rhino from the Chondon River (North of the Indigirka-Kolyma Lowlands) inhabited open larch forests and grassland landscapes. Considering the habitats, this species had a chance to survive there at least until the beginning of the Late Pleistocene (MIS5e), that is, their time lasted longer than previously thought. A phylogenetic analysis of complete mitochondrial genomes of extinct and extant rhinoceroses confirms the taxonomic morphological identification of the Altai and Chondon rhinos.