Arctic mammals wintered in darkness 53 million years ago.Byline: ANI Washington, June 2 (ANI): A new study has suggested that ancestors of tapirs and ancient cousins of rhinos living above the Arctic Circle Arctic Circle, imaginary circle on the surface of the earth at 66 1-2°N latitude, i.e., 23 1-2° south of the North Pole. It marks the northernmost point at which the sun can be seen at the winter solstice (about Dec. 53 million years ago endured six months of darkness each year in a far milder climate than today that featured lush, swampy forests. According to according to prep. 1. As stated or indicated by; on the authority of: according to historians. 2. In keeping with: according to instructions. 3. University of Colorado University of Colorado may refer to:
Order Monotremata Middle Cretaceous–Recent
de·cid·u·ous adj. 1. leaves and aquatic vegetation. "But, in winter's twilight they apparently switched over to foods like twigs, leaf litter, evergreen needles and fungi," said Eberle. The team used an analysis of carbon and oxygen isotopes extracted from the fossil teeth of three varieties of mammals from Ellesmere Island - a hippo-like, semi-aquatic creature known as Coryphodon, a second, smaller ancestor of today's tapirs and a third rhino-like mammal known as brontothere. "Animal teeth are among the most valuable fossils in the high Arctic because they are extremely hard and better able to survive the harsh freeze-thaw cycles that occur each year," Eberle said. Telltale isotopic signatures of carbon from enamel layers that form sequentially during tooth eruption allowed the team to pinpoint the types of plant materials consumed by the mammals as they ate their way across the landscape through the seasons, according to Eberle. "We were able to use carbon signatures preserved in the tooth enamel to show that these mammals did not migrate or hibernate See hibernation mode. ," she said. "Instead, they lived in the high Arctic all year long, munching on some unusual things during the dark winter months," she added. "An analysis of oxygen isotopes from the fossil teeth helped determine seasonal changes in surface drinking water drinking water supply of water available to animals for drinking supplied via nipples, in troughs, dams, ponds and larger natural water sources; an insufficient supply leads to dehydration; it can be the source of infection, e.g. leptospirosis, salmonellosis, or of poisoning, e.g. tied to precipitation and temperature, providing additional climate information," said Eberle. The results point to warm, humid summers and mild winters in the high Arctic 53 million years ago, where temperatures probably ranged from just above freezing to near 70 degrees Fahrenheit. The study has implications for the dispersal of early mammals across polar land bridges into North America and for modern mammals that likely will begin moving north if Earth's climate continues to warm. (ANI) Copyright 2009 Asian News International The Asian News International (ANI) agency provides multimedia news to China and 50 bureaus in India. It covers virtually all of South Asia since its foundation and presently claims, on its official website, to be the leading South Asia-wide news agency. (ANI) - All Rights Reserved. Provided by Syndigate.info an Albawaba.com company |
|
||||||||||||||
Printer friendly
Cite/link
Email
Feedback
Reader Opinion