The biggest mammal to have ever lived is the giant rhino or Paraceratherium, which lived 34-23 million years ago in China and spread all across Asia. However, how this mammal spread across Asia has been a mystery for scientists for a long, given the diverse topography of the area - mountains, plateau, sea beaches, deserts - which would obstruct the movement of such giant mammals. Moreover, scientists did not know how one species of giant rhinos - Paraceratherium bugtiense - evolved in Pakistan.
Now, scientists have found a new species of the mammal group, which unveils many important clues to how this spread became possible. The new species of the giant rhinos, named Paraceratherium linxiaense, was discovered from the fossil found in the Gansu Province of China, north of Tibet.
When paleontologists analysed the data from the preserved fossil, they found that the skull and bones belonged to a new species on the giant rhinos’ tree of life. The scientists studied the evolution of these bones to determine their position in the family tree. When they mapped all the six species of giant rhinos on the map, they found that Tibet played a central role acting as crossroads in their expansion across Asia.
However, to the doubt of how an area with a vast amount of elevated terrain played a central role, which would certainly be difficult for long movements of mammals this large, scientists found an answer that at that time, before 23 million years ago, the Tibetan region was not so much of tough terrain for them.
At that time, the “tropical conditions allowed the giant rhino to return northward to Central Asia, implying that the Tibetan region was still not uplifted as a high-elevation plateau," says Deng Tao, the lead author of the research, in a news release by the Chinese Academy of Sciences Headquarters. Tao works at the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP), CAS. The research was published in Nature Communications Biology on June 17.