Systematics and distribution of sheep of the genus Ovis (Artiodactyla, Bovidae) in Eastern Siberia and the Far East in the Pleistocene and Holocene [Russian]

摘要

The fossil and subfossil Siberian snow sheep, Ovis nivicola and giant (argali) sheep O. ammon found, are analyzed. Snow sheep were wide spread in the late Pleistocene and early Holocene: their range covered most of eastern Siberia and the Far East and the southern part of western Siberia. The argali area in Siberia was also larger in that time than nowdays: they inhabited the southern part of western and eastern Siberia up to the northern Transbaikal territory and southwestern Yakutia. The most ancient form among the sheep inhabiting southern parts of eastern Siberia from the Eopleistocene was argali-like. The Siberian snow sheep appears to originate from argali-like sheep at the end of the early Pleistocene or the beginning of the Middle Pleistocene in the mountains of southern Siberia. In the Middle Pleistocene, O. nivicola started settling to the north and northeast and reached Alaska by the Bering land bridge. A comparison of fossil remains of O. nivicola from Yakutia and Transbaikal region with the present subspecies O. n. lydekkeri and O. n. nivicola testifies that the former are similar to the latter. The fossil snow sheep from the southern part of western Siberia is worth considering as an independent subspecies (O. nivicola tomensis Gromova 1947). The validity of O. ammon fossilis Pavlova 1911, a fossil argali from Transbaikal and Cisbaikal regions, is confirmed. An additional description of this species is given.