Paleontologists have discovered a skull fossil of a Hipparion, a three-toed horse with a long nose that lived approximately 5 million years ago, in the northwestern province of Gansu, researchers said Friday, Feb 17.

According to Xinhua, the fossil, found in Dongxiang autonomous county in the city of Linxia in late January, was the most intact fossil of a Hipparion skull discovered in China to date, said Deng Tao, researcher with the Institute of Vertebrate Paleontology and Paleoanthropology under the Chinese Academy of Sciences.

The discovery provided vital clues for the study of structural features of the species, especially for the research of the "nasal notch," said Deng.

Originating in North America, the Hipparion is believed to have spread to the Old World over the Bering land bridge, which used to connect present-day Alaska and eastern Siberia.

Linxia is located in the northeast edge of the world's highest and largest plateau, the Qinghai-Tibetan Plateau. Many mammal fossils have been found in the city.