HR: 08:00h
AN: GC11B-01    [Abstracts]
TI: Fossil Find on Svalbard Highlights the Natural History of the Polar Bear (Ursus maritimus)
AU: * Ingolfsson, O
EM: oi@hi.is
AF: University of Iceland, Department of Earth Sciences Askja, 232, Reykjavik, Is-101, Iceland
AU: Wiig, O
EM: oystein.wiig@nhm.uio.no
AF: Natural History Museum, University of Oslo P.O.Box 1172 Blindern, Oslo, N-0318, Norway
AB: During recent fieldwork on Svalbard a well preserved subfossil left ramus of a polar bear (Ursus maritimus) mandible was discovered. A 14C age determination shows that it is older than 45 ka (kilo-years), and an OSL (Optical Stimulated Luminescence) age determination together with the stratigraphic position of the bone suggests that it is of Eemian-Early Weichselian/Wisconsinan age, 150-80 ka old. This puts the find among the oldest fossil remains of a polar bear ever discovered. Osteological study of the mandible suggests that it comes from a fully grown female. The fossil record suggests that polar bears may have developed from brown bears during the early part of the last glacial cycle, some 100 ka ago. The present interglacial might be the first such that the species has to endure. This underlines the potential status of the polar bears as an endangered species if the current warming trend and diminishing of sea ice cover in the Arctic continues.
DE: 1225 Global change from geodesy (1222, 1622, 1630, 1641, 1645, 4556)
DE: 3344 Paleoclimatology (0473, 4900)
SC: Global Environmental Change [GC]
MN: 2007 Fall Meeting