Fossil bears (Carnivora, Ursidae) from Krasny Yar locality (Krivosheinsky Area, Tomsk Region).2. Postcranium remains and palaeoecology issues

This paper presents the second part of bone material researchon fossil bears from the locality of Krasny Yar (Krivosheinsky area, Tomsk region), including postcranial remains. The bones ofpostcranial skeleton are described and measured in assemblage, without reference to this or that species, because of the difficulties indefinition of a specific belonging. The comparison of tubular bones with materials was made on a brown bear from Pamyatnaya cave(Kuznetsky Alatau) [Vasiliev, Grebnev, 2009] and Ursus savini rossicus from Ural [Kuzmina, 2002]. Besides the morphologicalanalysis of bone material, the paper includes brief research history of the fossil bears on the territory of the West Siberian Plain. It ismarked that the oldest cave and brown bear remains are from Tobolsk horizon, Middle Neopleistocene. By the end of Karginian time(Late Neopleistocene) the small cave bear disappears all over the territory of Western Siberia (the latest date is 31870±190 years) and inlocalities of Sartanian age its remains are already absent [Kosintsev, Vasiliev, 2009]. It is quite possible, that Ursus savini rossicusremains from Krasny Yar are one of the latest - the age of the middle bone bed stratum with remains of mammuthus faunarepresentatives lies in the interval of 18505-25650 years [Shpansky, Chernous, 2012], covering the end of Karginian - the beginning ofSartanian time. The joint finding of the remains of two species of bears in the same locality means their joint habitation in closeconditions or periodic visiting of the same landscape sites (for example, watering places). The structure of teeth and limb bones of smallcave bear means its habitation mainly in open landscapes, and brown bear - in lowland sites. The assumption of possible feeding ofbrown and cave bears not only by vegetative food, but also by easily accessible corpses of the lost animals in the conditions of a longtermfrozen ground is made. Besides, grassy food and food of animal origin was available all-year-round and could satisfy constantrequirement for meal and reduce or even exclude hibernation of bears. In present time brown bear hibernation is connected with strategyof food searching and is a compulsory measure for overcoming the adverse (without food) period. In modern forest conditions(representing landscape refuges) with the thick snow cover carrying out thermal protection function, winter hibernation is goodbehavioural and physiological adaptation. The landscape-climate situation of Late Neopleistocene was absolutely the opposite: openlandscapes with the poorest snow cover [Shpansky, 2003] were extremely improper for the arrangement of the dens.

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