Perennially frozen Upper Quaternary deposits, particularly in of Northern Yakutia, contain a wealth of various organic remains. Fossils of different groups complement each other in their paleoecological implications. The Late Pleistocene environments have been reconstructed using these finds combined with the integrated sedimentary research. Recent multidisciplinary studies of the perennially frozen deposits have greatly improved our knowledge of the environmental history of the region. They have been carried out in the course of the Russian-German science cooperation « SYSTEM LAPTEV SEA» (1998-2006).

Abundance of fossil mammal bones (more than 4000 samples) has been collected over the coastal lowlands, in the Lena Delta, New Siberian Islands and Anabar-Olenyok Region. Our unique collection is supported by an extensive programme of radiocarbon dating of bone collagen. For the first time paleonthological collections and absolute ages of fossil large mammals are available for all islands of the New Siberian archipelago. The Holocene date on a fossil horse skeleton from Kotelny Island (Cape Anisiy) supports our previous suggestion about widespread distribution of horses in the Arctic during the Holocene.

Based on different paleontological investigations we distinguish several paleoenvironmental stages during the Late Pleistocene and Holocene. The period с 60-50 kyr BP is characterized by low bioproductivity and dry cold summer. Second period с 50-25 kyr BP reflects more favorable living conditions with high bioproductivity. The summers were apparently warmer but drier than today. Based on the density of the mammal population this stage was subdivided into two intervals: с 50 kyr BP to 35-34 kyr BP and 33 kyr BP to 23-22 kyr BP. During the second interval environmental conditions deteriorated as compared to the previous interval. The period of extremely cold and arid environment, most unfavourable for the mammoth, occurred probably between 22 kyr BP and 15 kyr BP. A strong environmental change is noted in all records of the post Last Glacial Maximum period between 15 and 9 kyr BP. It can be interpreted as a climatic amelioration. The reconstructed temperatures and precipitation were higher than today. It probably was a period of the greatest density of the woolly mammoth in this region.

Reference:

Kuznetsova T.V., Schirrmeister L., Sulerzhitsky L.D., Kuzmina S.A., Andreev A.A., Grosse G., Kienast F., Siegert Ch., Kunitsky V.V. Paleontological studies of Upper Quaternary deposits in the Laptev Sea region. Correlation of Pleistocene Events in the Russian North. International Workshop Abstracts. 4-6 December 2006. Saint-Petersburg, 2006, p. 50.