Fossil Teeth Bring New Insight into Prehistoric Arctic Mammals
02.06.2009 - Flora & Fauna, Other, Arctic
According to a new study published in the June issue of Geology, prehistoric mammals which once roamed the Arctic lived in a much milder climate than today: from just above freezing to about 21°C (70°F). This discovery has implications for the dispersal of early mammals across polar land bridges into North America but also for modern mammals that should start moving north if Earth's climate continues to warm.
By analyzing carbon and oxygen isotopes extracted from the fossil teeth of three varieties of mammals, scientists from the University of Colorado at Boulder were able to show:
- the types of plant materials consumed by the mammals throughout the seasons (flowering plants, deciduous leaves and aquatic vegetation during the summer; twigs, leaf litter, evergreen needles and fungi during the winter);
- that these animals did not migrate or hibernate (they lived in the high Arctic all year long, munching on some unusual foods);
- that seasonal changes in surface drinking water was tied to precipitation and temperature (warm, humid summers and mild winters).
This evidence pinpoints to the year-round presence of mammals in the high Arctic and to the probability of their eventual dispersal across land bridges linking Asia and Europe to North America, as the climate shifted over millions of years.
The new Geology study also hypothesizes the impacts of pursued warming in the Arctic. As the temperatures warm in the coming centuries and millennia, scientists evoke the possibility of new intercontinental migrations, as lower-latitude mammals start migrating north.
