Woolly rhinoceros fossil in Tibet believed to be 3.7 million years old
LOS ANGELES — Searching across the Tibetan plateau, paleontologists have discovered a species of woolly rhinoceros that may be an ancestor of the great Ice Age beasts that roamed the icy plains of North America, Europe and Asia.
The Coelodonta thibetana fossil dates to about 3.7 million years ago, about a million years before other known woolly rhinos. The findings, published in Friday’s edition of the journal Science, lead researchers to believe that before the Ice Age began, the chilly Tibetan highlands may have served as an evolutionary cradle for cold-hardy mammals whose descendants thrived in the glacial times that followed.
Paleontologists have yet to fully trace the origins of many of the giant, hairy beasts that lived during the most recent Ice Age, which lasted from about 2.6 million to 10,000 years ago. Many of these animals, whose massive bodies conserved heat effectively, were thought to have evolved in Eurasia from animals that managed to survive and adapt to an increasingly cold environment.
The new fossil from the Zanda Basin in Tibet may provide an alternative evolutionary explanation for some of those animals, said study co-author Xiaoming Wang, a vertebrate paleontologist with the Natural History Museum of Los Angeles County.
The fossil is a new species of rhinoceros that had developed cold-hardy attributes at least a million years before the Ice Age got under way. The rhino, about 10 percent lighter than its Ice-Age descendant, had a hairy body and a flattened horn useful for sweeping away snow to get at the vegetation underneath.
The team also found other creatures — blue sheep, snow leopards and Tibetan antelope — that had acquired similarly snow-ready qualities. Perhaps this part of Tibet had been a specialized breeding ground for cold-tolerant animals that were able to thrive and spread once the big freeze hit. It will take more digging to find out.
