Ice Age megafauna have long been known to be associated with
global cooling during the Pleistocene, and their adaptations to
cold environments, such as large body size, long hair, and snow-
sweeping structures, are best exemplified by the woolly mammoths
and woolly rhinos. These traits were assumed to have evolved as
a response to the ice sheet expansion. We report a new Pliocene
mammal assemblage from a high-altitude basin in the western
Himalayas, including a primitive woolly rhino. These new Tibetan
fossils suggest that some megaherbivores first evolved in Tibet
before the beginning of the Ice Age. The cold winters in high
Tibet served as a habituation ground for the megaherbivores,
which became preadapted for the Ice Age, successfully expanding
to the Eurasian mammoth steppe. A, Skull and cheek teeth of
Coelodonta thibetana. B, Origin, distribution, and dispersal of
woolly rhinos in Eurasia. (Image by DENG Tao) Skull and lower
jaw of the extinct Tibetan woolly rhino, Coelodonta thibetana.
Credit: DENG Tao