AsianScientist (Sep. 2, 2011) – The discovery of a primitive woolly rhino fossil in Tibet suggests that some giant mammals first evolved there before the beginning of the Ice Age.
The extinction of Ice Age giants such as woolly mammoths, woolly rhinos, giant sloths, and saber-toothed cats has been widely studied, but much less is known about where these giants came from, and how they acquired their adaptations for life in a cold environment.
A team of geologists and paleontologists, led by Xiaoming Wang from the Natural History Museum of Los Angeles County (NHM) and Qiang Li of Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, uncovered a complete skull and lower jaw of a new species of woolly rhino (Coelodonta thibetana) in the foothills of the Himalayas in the southwestern Tibetan Plateau.
The finding is published in this week’s issue of the journal Science.
“Cold places, such as Tibet and the Arctic and Antarctic, are where the most unexpected discoveries will be made in the future – these are the remaining frontiers that are still largely unexplored,” said Wang.
The new rhino is 3.6 million years old (middle Pliocene), much older and more primitive than its Ice Age (Pleistocene) descendants in the mammoth steppes across much of Europe and Asia.
The extinct animal had special adaptations for sweeping snow, using its flattened horn to reveal vegetation, a useful behavior for survival in the harsh Tibetan climate.
The rhinos lived at a time when global climate was much warmer and the northern continents were free of the massive ice sheets seen in the later Ice Age. The rhino grew accustomed to cold conditions in high elevations, and became “pre-adapted” for the future Ice Age climate.
When the Ice Age eventually arrived, the cold-loving rhinos simply descended from the high mountains and began to expand throughout northern Asia and Europe.
In addition to the new woolly rhino, the paleontologists uncovered extinct species of three-toed horse (Hipparion), Tibetan bharal (Pseudois, also known as blue sheep), chiru (Pantholops, also known as Tibetan antelope), snow leopard (Uncia), badger (Meles), as well as 23 other kinds of mammals.
The article can be found at: Deng T et al. (2011) Out of Tibet: Pliocene Woolly Rhino Suggests High-Plateau Origin of Ice Age Megaherbivores.
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Source: National Science Foundation.
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