June 11, 2009 -- The creatures that roamed the balmy swamps and forests of the prehistoric Canadian high Arctic survived the long dark season by switching diets dramatically, according to a new study. Instead of migrating south or hibernating for the winter like most animals today, they endured, foraging in dormant forests through the long polar gloaming. Today Canada's Ellesmere Island is a frigid tundra. But 53 million years ago it resembled a Louisiana bayou, teeming with plants and crowded with alligators, turtles, and tapirs. Even lemur-like creatures swung from the trees. Scientists have long wondered how the animals survived the long winter. Though temperatures didn't often get below freezing, plants must have gone into hibernation during the six months of darkness. New evidence extracted from the teeth of the hippopotamus-like Coryphodon suggests they subsisted on leaf litter, decaying fruits and twigs through the winter. Jaelyn Eberle of the University of Colorado in Boulder and a team of researchers sampled carbon isotopes from the teeth of nine Coryphodons, three tapirs and two rhinoceros-like brontotheres, all of which lived on ancient Ellesmere. Related Content:
The results show the plant-eaters lived off of abundant flowering plants, leaves, and greenery in the spring and summer months. But in the winter they switched to eating dead and dying plant matter and fungi. "People first discovered alligators in the high Arctic in 1975, and I've been going up there since the 1990's," Eberle said. "But we never thought to stop and ask 'why?' or 'how?' How were these animals able to survive up there -- what made them special?" |
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