Taxonomic composition of small vertebrates from the pleistocene deposits in the south chamber of Denisova cave

The article presents the results of the study of small vertebrate bone remains from the Pleistocene deposits in the South Chamber of Denisova Cave. The taxonomic structure of fossil communities was established by 10,842 bones from lithological layers 16-11. According to preliminary data, this part of the profile formed in the interval from the end of MIS 7 to the first half of MIS 3. The general paleogeographic assessment of the natural complexes of the Anui River valley indicates mosaic landscapes during the accumulation of layers 16-11. Taiga massifs alternated with areas of steppe and meadow biotopes. The river flow regime did not change fundamentally. Covering glaciers did not affect this region. Climatic fluctuations were reflected in the changing ratios of the dispersal areas of the forest, steppe, rocky and meadow biotopes. The general trend of climate and natural association changes was expressed in the gradual reduction of forest and expansion of steppe and meadow biotopes. The study of bone samples from the South Chamber showed that the preservation of paleontological material in the sediments in this part of the cave is somewhat better than in the taphocenoses of the Main and East Chambers. Better preservation of bones throughout the section makes it possible to refine the identification and supplement the taxonomic composition of small mammals. Analysis of the ground squirrel cheek teeth morphology from the deposits of layers 16, 15, 13, and 12 showed that they belong to the fossil red-cheeked ground squirrel Spermophillus erythrogenis palaeosibiricus. In the fossil record of layer 11, a form that predates the present-day field vole Microtus agrestis has been preserved, which indirectly indicates the time of the emergence of this taxon.