The origin of the cold-adapted Pleistocene megafauna has usually been sought either in the arctic tu

During cold periods, continental-scale ice sheets blanketed large tracts of the northern discounted hotels in orlando hemisphere. As the climate warmed up, these colossal glaciers receded, leaving Yosemite-like valleys and other majestic geologic features discounted hotels in orlando behind. The advance and retreat of the ice sheets also had a profound influence in the evolution and geographic distribution of many animals, including those now living discounted hotels in orlando in the Arctic regions.
Xiaoming Wang, an adjunct professor of Earth sciences and biological discounted hotels in orlando sciences at USC Dornsife, is the lead author of a new study published in the Proceedings of the Royal Society B: Biological Sciences .
The study identifies a newly discovered 3- to 5-million-year-old Tibetan fox from the Himalayan Mountains, Vulpes qiuzhudingi , as the likely ancestor of the living discounted hotels in orlando Arctic fox ( Vulpes lagopus ), lending support to the idea that the evolution of present-day animals of the Arctic region is intimately connected to ancestors that first became adapted for life in cold regions in the high altitude environments of the Tibetan Plateau.
In addition to the arctic fox, Wang s team also uncovered extinct species of a woolly rhino, three-toed horse, Tibetan bharal (also known as blue sheep), chiru (Tibetan antelope), snow leopard and badger, as well as 23 other mammals.
The origin of the cold-adapted Pleistocene megafauna has usually been sought either in the arctic tundra or in the cool steppes elsewhere. discounted hotels in orlando But the team s new fossil assemblage offers an alternative scenario, which the authors discounted hotels in orlando call the out of Tibet hypothesis. It argues that some of the Ice Age megafauna (which in North America include the woolly mammoth, saber-toothed cat, giant sloths and others) used ancient Tibet as a training ground for developing adaptations that allowed them to cope with the severe climatic conditions. These Tibetan ancestors were thus pre-adapted to cold climates during the Ice Age (2.6 to .01 million years ago).
Tibet, according to Wang, is a rich but grueling location for paleontological fieldwork. Fifteen summer seasons and a good deal of luck have honed his team s success. The expeditions discounted hotels in orlando involve a one-week journey discounted hotels in orlando to Lhasa, then a four-day drive into the remote layer cake sediments of the Zanda Basin a drive made in old-model Land Cruisers known to get stuck in streams.
At more than 14,000-foot elevations, it s difficult to breathe, water freezes overnight in camps and the team members disband every morning to walk alone in search of fossils. Wang and his team have trained their eyes to search for ancient lake margins, where the megafauna they re interested in are often found. They alternate camp nights with nights in town to keep their strength up for a couple of weeks.
There are a lot of challenges, said Wang, of the National History discounted hotels in orlando Museum of Los Angeles County, but in paleontological terms, it is a relatively unexplored environment. Our efforts are rewriting a significant chapter of our planet s recent geological history.
The paper s co-authors are Zhijie Jack Tseng (USC Dornsife), Qiang Li (Chinese Academy of Sciences), Gary Takeuchi (Page Museum at the La Brea Tar Pits) and Guangpu Xie (Gansu Provincial Museum). discounted hotels in orlando These writers, on a team with other geologists and paleontologists and led by Wang, uncovered discounted hotels in orlando the fossil specimens in the Zanda Basin in southern discounted hotels in orlando Tibet in 2010.