Rare snow leopard fossils trace evolutionary history of species

BEIJING -- An international research team has revealed the snow leopard's unique evolutionary path by studying rare snow leopard fossils discovered across the Eurasian continent.

The study, published Thursday in the journal Science Advances, was conducted by researchers from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), and the Institute of Zoology, both under the Chinese Academy of Sciences, along with collaborators from Italy, Portugal and France.

The snow leopard, a large feline native to the Qinghai-Xizang Plateau and its surrounding regions, is renowned for its adaptations to extreme high-altitude environments. Due to the scarcity of fossil evidence from the plateau region, it's unclear how snow leopards evolved their specialized adaptations to this environment.

The researchers analyzed five snow leopard fossil records from various locations outside the Qinghai-Xizang Plateau, including Beijing, Northwest China's Gansu province, France and Portugal. By combining DNA sequences with morphological data, they determined that the fossil snow leopards were not an independent lineage but small offshoots of the main snow leopard branch.

"It is likely that these offshoots represent multiple dispersals of snow leopards out of the Qinghai-Xizang Plateau at different times," said Deng Tao, a researcher from the IVPP.

By comparing key morphological features of fossil snow leopards with modern specimens, the team found evidence that the species underwent significant changes during the Middle Pleistocene period.

"This timeframe coincides with the emergence of large ice sheets on the Qinghai-Xizang Plateau," said Wang Shiqi, a researcher from the IVPP.

Since the Middle Pleistocene, increased global climate variability has led to more severe and prolonged glacial periods. These conditions likely enabled snow leopards to expand their range beyond the Qinghai-Xizang Plateau, Wang explained.

Notably, the Middle Pleistocene also marks the period when many members of the Caprinae sub-family began to migrate from the Qinghai-Xizang Plateau into North China and Europe, paralleling the movement of snow leopards from the plateau, he added.

The study also revealed that while the fossil sites are generally located at relatively low elevations, they were situated in mountainous environments.

"It suggests that mountainous terrain and the availability of related prey may have been more critical for snow leopards than the high-altitude, low-oxygen conditions," Deng said.

"These insights are important to the ongoing conservation efforts of the flagship species on the Qinghai-Xizang Plateau and also prove the usefulness of preservation paleontology," he added.