A new fossil assemblage found in Southwest China's Tibet Autonomous Region suggests that the ancestors of some giant Ice Age mammals evolved in Tibet before the beginning of the Ice Age.

The fossils from the high-altitude Zanda Basin at the foothills of the Himalayas in Southwest Tibet include the remains of the earliest known species of woolly rhino, one of the Ice Age's most iconic mammals, said a statement from the Chinese Academy of Sciences (CAS).

The research was conducted by a team of Chinese and foreign scientists led by Deng Tao and Wang Xiaoming, researchers of the CAS's Institute of Vertebrate Paleontology and Paleoanthropology.

Ice Age giant mammals have long been associated with their adaptations to cold-weather environments, including their large body size, long hair and snow-sweeping structures, and are best exemplified by woolly mammoths and woolly rhinos, the statement said.

The recently uncovered Tibetan woolly rhino, named Coelodonta thibetana, lived in the middle Pliocene around 3.7 million years ago, before the Ice Age, or Pleistocene, began about 2.8 million years ago.

The woolly rhino is likely not the only case of a Tibetan cold-adapted ancestor to Ice Age megafauna.

Cold winters in high-altitude Tibet served as a habituation ground for the Tibetan woolly rhino and the predecessors of some other Ice Age mammals, which became pre-adapted for the Ice Age, the statement said.

This means that these animals first evolved in Tibet, Deng Tao said.

Some previous hypotheses speculated that the animals originated in Arctic regions.

Previous fossil records have suggested that the woolly rhino evolved in Asia, but its early ancestry remained elusive, and the recently uncovered fossils in Tibet exposed the most primitive representatives of the genus, Deng said.

As the Ice Age began, the Tibetan woolly rhino left the high plateau region and descended to low-altitude, high-latitude regions in northern Eurasia and evolved into one of the Ice Age mammals, he said.

The discovery was published in Science, a scientific journal, on Friday.