Giant rhino, Paraceratherium, were mainly found in Asia, according to a press release from the Chinese Academy of Sciences, published Friday.
The new species, Paraceratherium linxiaense, or Linxia Giant Rhino, was named by a Chinese and US team led by Deng Tao from the Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) at the academy, which analyzed fossils found in 2015.
"Usually fossils come in pieces, but this one is complete, with a very complete skull and a very complete jaw, which is rare," Deng told CNN.
"The skull was more than a meter (three feet) long, and it was very rare for a skull of that size to be preserved. We also found the cervical spine," he said.
The fossils were found in the Linxia basin in Gansu Province, northwestern China, and genetic analysis showed that they belonged to a new species of giant rhino.
The huge animal would have weighed 24 tons and was the same size as six elephants, Deng told CNN. Its shoulders were more than 16 feet off the ground, the head at 23 feet, and its body was 26 feet long, he added.
By way of comparison, adult male giraffes may exceed 18 feet in height, with females reaching around 14 feet.
"This is the largest mammal ever to have lived on land," Deng said.
It mainly lived in China, Mongolia, Kazakhstan and Pakistan, with a few in Eastern Europe, he added.
Giant rhino lived in the northern part of the Tibetan plateau around 31 million years ago, before migrating southwest to Kazakhstan and then Pakistan.
The Linxia Giant Rhino is descended from those that lived in Pakistan. They would have had to cross the Tibetan plateau on their way north to Linxia, which means the plateau was lower than it is now, Deng said.
"In addition, animal migration is linked to climate change. So 31 million years ago, when the Mongolian plateau dried up, they moved south," he added.