New fossil marmot materials from Minusinsk depression and its distribution in the region (Southern Siberia)

The high variety of the landscapes on the territory of the Minusinsk depression in the Late Pleistocene contributed to the high mammals biodiversity. The change of the Pleistocene fauna to recent fauna occurred due to the extinction of a significant part species in region. A Groundhog became one of these animals. The fossil remains of Marmota Blumenbach, 1779 are regularly found in many locations in the region. The Groundhogs remains at the localities of region are identify is Marmota sp., Marmota baibacina Kastschenko, 1899 or Marmota sibirica Radde, 1862. There was no consensus among researchers regarding what kind of marmots species lived in the Minusinsk depression during the Pleistocene and Holocene. The reliable species identification of fossils is only possible from the cranial remains. Fragments of two individuals skeletons, as well as some other materials on fossil marmots from the territory of Minusinsk depression are described in this work. Three skulls, two lower jaws and numerous postcranial remains are present in the collection. Mor-photype "b" of the position of the lacrimal bone structure characteristic of the all skulls. The study of Marmota fossil remains of enabled, be sure to identify them as belonging to the same species Marmota baibacina. Available materials showed homogeneity in the structure and size of the marmot skeleton during the Late Pleistocene and Holocene. The Holocene marmot remains are somewhat larger than the Late Pleistocene marmot. Probably the larger size of the Holocene marmots may be associated with sexual variability. Numerous of the marmots remnants are excavated in many localities of Karga, Sartan and Holocene. The youngest of Marmota remains was come from caves in the western part of the region. These caves have an age of about 1500-2000 years BP. Thus, one can confidently assert that the population of the Altai marmot Marmota baibacina is continuously lived within the Minusinsk depression from the second half of the Late Pleistocene to the Late Holocene. We are not able to compare our material with previously published by other researchers. Therefore, we do not exclude that in addition to the gray marmot, other representatives of the Marmota genus could inhabit in the region. Revision of existing materials, as well as new finds remnants of marmot from different parts of the region are needed for a definitive answer to the question of how many marmots species are lived in Minusinsk depression and for whatever reason they are extinct in region.

Keywords

Authors

References