Large Mammals of the Early, Middle and Late Pleistocene in the Novosibirsk Ob Region
The author analyzes the Pleistocene megafauna from two large localities in the Novosibirsk Ob region - Krasny Yar and Bibikha. 5768 bone remains from 28 large mammals were collected from Krasniy Yar layers 4 and 6. The fossils have been dated to the Early, Middle and Late Pleistocene - Kazantsevian (R-W) and Karginian (W-2) periods. 5708 bones from 19 species were found at Bibikha. Most of the finds from Bibikha are dated by the biostratigraphic method to the Middle Pleistocene, fewer bones belong to the Early Pleistocene. All the bone remains from Bibikha were collected in a redeposited position on the beach. The taphonomic features of both localities are analyzed. The study of the bones of large mammals showed that the body sizes of the bison, red and giant deer, elk and cave lion were the same during the period from the Middle to the initial Late Pleistocene. On the contrary, the average height at the withers of horses during the early - second half of the Late Pleistocene decreased. The Early Pleistocene fossil group from Krasny Yar and Bibikha includes remains of Panthera leo fossilis, Mammuthus sp., Coelodonta antiquitatis, Equus ferus (ex. gr. mosbachensis), Megaloceros giganteus, Cervus elaphus, Cervalces latifrons, Bison priscus, Praeovibos sp., Soergelia cf. elisabethae. In the Middle and Late Pleistocene, two species absolutely dominated - the bison and the horse. Their bones add up to 68 - 79 % of all megafauna remains. During the periods of interglacials and interstadials, the bison population was greater in the predominating forest landscapes (48-52 %); the horse remains made up 20-26 %. During periods of glaciation, the horse dominated (up to 63 %) under the conditions of cooling and development of arid steppe landscapes, while the number of bison fossils decreased by three or more times.