Smithsonian.com

Woolly rhinos may have used their flattened horns to sweep away snow and expose edible vegetation underneath.(image by Julie Naylor)

While some scientists investigate just what caused the extinction of large mammals such as mammoths and giant ground sloths at the end of the last ice age, others are looking at the other side of things—how and where these creatures evolved. And now scientists from the Chinese Academy of Sciences and elsewhere have come up with a good possibility for the woolly rhino: Tibet. (Their study appears in this week’s issue of Science.)

A team of geologists and paleontologists found a complete skull and lower jaw of a new species of woolly rhinoceros, which they named Coelodonta thibetana, in the high-altitude Zanda Basin at the foothills of the Himalayas in southwestern Tibet. The fossil dates to about 3.7 million years ago, the middle Pliocene. The scientists posit that the woolly rhino evolved there in the cold, high-elevation conditions of Tibet and when the Ice Age began, 2.6 million years ago, it descended from its mountainous home and spread throughout northern Asia and Europe.

“The harsh winters of the rising Tibetan Plateau could well have provided the initial step toward cold adaptation for several subsequently successful members” of the group of large mammals we associate with the Ice Age, the scientists write.