The find was made in the country's northwest Gansu province, China's state-run news agency Xinhua reported.
The fossil was the most intact fossil of a Hipparion skull discovered in China to date, said Deng Tao of the Institute of Vertebrate Paleontology and Paleoanthropology at the Chinese Academy of Sciences.
The discovery has yielded vital clues for the study of structural features of the species, especially for the research into the so-called "nasal notch," Deng said.
The Hipparion originated in North America and is thought to have spread to the Old World over the Bering land bridge that once connected present-day Alaska and eastern Siberia, researchers said.
The fossil find was made on the edge of the world's highest and largest plateau, the Qinghai-Tibetan Plateau, site of many mammal fossil discoveries, they said.
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