Vertebrate fossils excavated from the Bol'shoj Naryn site, East Siberia

Located at approximately 53°N, 103°E, the Bol'shoj Naryn site lies on the hills facing Osa Bay, in the Bratsk Reservoir. The authors started excavating this site in 2003. By 2005, we had found 337 stone tools and flakes, and more than 600 animal fossils, from the paleosol layers (¹⁴C dating: from 25,000 to 32,000 yr BP) deposited in the second half of the Karginian Interstadial. Large specimens of the fossils collected by visual observation were mostly the bones and teeth of Equus sp. and Bovinae, and small specimens obtained through wet sieving included many fossils of Lagurus lagurus, Microtus sp., and Spermophilus undulatus. This suggests that the steppe had spread around this site by the last half of the Karginian Interstadial. However, some of the animal fossils collected from the Bol'shoj Naryn site were characteristic of tundra or forest, as well as steppe. To understand why, remains characteristic of three different habitats were excavated from the same paleosol of the Karginian Interstadial, detailed discussions centered on the radiocarbon age of each material are needed. As part of our investigation of the fossils of large vertebrates, we measured various parts of the fossils of Eanus sp. in excavated specimens and in specimens collected from the reservoir's shore, in accordance with the procedure described by von den Driesch [1976. A Guide to the Measurement of Animal Bones from Archaeological Sites. Peabody Museum of Archaeology and Ethnology Bulletin 1, Peabody Museum, Harvard University, Cambridge, MA]. We inserted the measured values into the formula of Nishinakagawa et al. [1991. A study on the time and the route of the introduction of cattle and horses into Japan, as examined from skeletal remains of archaeological sites. Report of the Grant-in-Aid from the Ministry of Education, Culture, Sports, Science and Technology, Scientific Research (B) 1990 (Japanese, English abstract)] and found that the collected fossils were mostly of individuals with withers heights between 125 and 135 cm. To clarify the time transition, a future project will use measurements to examine the trait characteristics of the fossils of other large mammals. In future, we intend to clarify the histories of nature and humankind in the Pleistocene in the Fore-Baikal region and to add animal fossils excavated from other sites to the scope of our research.