Remains of fossil bears (Carnivora, Ursidae) from Krasny Yar locality (Krivosheinsky area,Tomsk region)

In the paper the results of bonematerial research on fossil bears from the locality of Krasny Yar (Krivosheinsky area, Tomsk region) are given. The locality is on theOb River in 105 km to the north of Tomsk. Radiocarbon data in the interval from 18505±215 (SBRAS-5555) up to 25650±420(SBRAS-5201) have been received on the remains of the mammoth and the elk from this locality. The first article includes thedescription of cranial remains. For comparison of skulls the skull of a big cave bear Ursus ex gr. spelaeus-ingressus (odessanus),presumably found in the Ural Mountains and stored in the Palaeontological Museum of Tomsk Polytechnic University, is used. As aresult of the study it has been learnt that the remains from Krasny Yar belong to two species of bears - small cave (Ursus savini rossicusBorissiak) and brown (Ursus arctos L.). For each species of bears by the bones with the same name there are a minimum of threeindividuals. Earlier the lower jaw of the bear of Deningeri (Ursus cf. deningeri Reich.) was described by E.V. Alekseeva [1980]. Later,G.F. Baryshnikov [2005] classified it to the small cave bear of the Middle Neopleistocene. The skull of a small cave bear (the sample ofPM TSU № 5/2340) belongs to a very old male individual. The teeth are considerably worn out, which is proved by a complete loss ofenamel on the surface of teeth and imperforation of Р4 alveolus. The size of the skull (the condylobasal length is 358.5 mm) exceeds theknown sizes (343-352 mm, [Baryshnikov, 2007]) for this species. The occipital condyles width in relation to the condylobasal length isless than 19%. According to G.F. Baryshnikov [2007] it is a diagnostic feature for Ursus savini rossicus. Three of the four mandibles arereferred to as belonging to Ursus arctos and one to Ursus savini rossicus. Earlier two more mandibles of a small cave bear from thislocality have been described [Alekseeva, 1980; Baryshnikov, 2007]. The mandibles of the small cave bear have longer dentition P4-M3of 89.9-99mm against 80-83mm of the brown bear. The height of the horizontal branch behind М1 for the small cave bear is 50.8-56mm, for the brown bear it is 40-54mm.

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