Methodological aspects of studying small mammals from Chagyrskaya cave (Northwestern Altai) using the evidence from the field season of 2019 complex

The article analyzes the methods for studying fossil small mammals - a group which is traditionally used in landscape and climate reconstructions of the past. Evidence from Chagyrskaya cave (Northwestern Altai) excavated during the last field season was studied. Stratigraphic analysis of cave deposits has shown that layer 6A was relatively undisturbed in the excavation area. Complex of small mammals was analyzed using different approaches: mathematical calculations of preservation indices and conditional amount of material evidence, as well as morphological analysis of non-cranial fragments. The results obtained by different methods have been compared. Over a half of bones were unidentifiable. It has been shown that the maximum share among bone remains, taking into account the unidentifiable fragments, consisted of unidentified remains and cheek teeth of voles. The distribution of remains became more obvious without them. The distribution of dominant groups, taking into account the minimum number of individual animals, differed insignificantly from the distribution without taking into account this indicator due to specific taphonomic features. When calculating the preservation degree of vole cheek teeth, this indicator came close to zero, since only isolated teeth have been found in the layer. Identifiable postcranial fragments of small mammals expanded the list of taxa. This study has proven that the method of percentage ratio of remains belonging to small mammals without fragments, defined with the accuracy of families and tribes, is the most useful for paleo-reconstructions. The notion of “probable number of individuals” is preferable when describing the total composition of the fauna. Calculation of preservation degree of the complex is possible with well-preserved upper and lower jaws. Definition of postcranial elements is always desirable for medium-sized rodents and lagomorphs.