As a part of the late Pleistocene megafaunal extinctions, the woolly mammoth (Mammuthus primigenius) disappeared from Eurasia ca. 12-10000 years ago.  The species survived, however, for thousands of years after the mainland extinction on Wrangel Island, situated off the coast of Eastern Siberia.  The last known occurrence of the woolly mammoth is radiocarbon dated to 4000 years ago. The life and times of the woolly mammoth are investigated in a collaboration between researchers at the Laboratory of Chronology, the Department of Geosciences and Geography at the University of Helsinki, and the University of Tübingen. The study material consists of subfossil bones and teeth (pictured below) of the woolly mammoth, which bear chemical signatures of their living conditions.

The isotopic composition of oxygen in the tooth enamel of mammoth teeth is linked to the climatic conditions via the drinking water of the animal, and describes the rainout patterns and ancient air temperatures of ice age Europe (Arppe & Karhu, 2010). The carbon isotope composition reflect regional differences in the diet and living environment of European mammoths (Arppe et al., 2011). The strontium isotope values of the Wrangel Island mammoths describe the movement patterns of the animals and record the isolation process of the island from the mainland (Arppe et al., 2009). According to current scientific literature the climate and vegetation of Wrangel Island did not chage significantly after the beginning of the Holocene period (ca. 10000 years ago), and studies of ancient-DNA reveal no loss of genetic diversity nearing the extinction. Thus the reason for their seemingly abrupt disappearance remains unresolved. In the ongoing collaborative investigation, the oxygen isotopic composition of the Wrangel Island mammoth teeth are used to draw a picture of climate, while carbon and nitrogen isotopes are analysed on collagen extracted from the skeletal materials to study the diet of the animals.

References:

Arppe, L., Karhu, J.A., 2010. Oxygen isotope values of precipitation and the thermal climate in Europe during the middle to late Weichselian ice age. Quaternary Science Reviews 29, 1263–1275.

Arppe, L., Aaris-Sørensen, K., Daugnora, L., Lõugas, L., Wojtal, P., Zupins, I., 2011. The palaeoenvironmental d13C record in European woolly mammoth tooth enamel. Quaternary International 245, 285–290.

Arppe, L., Karhu, J. A. & Vartanyan, S. L., 2009. Bioapatite Sr-87/Sr-86 of the last woolly mammoths-Implications for the isolation of Wrangel Island. Geology  37, 347–350.