A skull from one of the largest mammals to have ever lived has been found in northwest China.
The “completely preserved” 26.5 million-year-old fossil comes from an extinct species of giant rhino measuring 16 feet at the shoulder, taller than a giraffe, and weighing 20 tonnes – as much as four African elephants.
Researchers have named the newly discovered species Paraceratherium linxiaense.
They say it lived in the late part of the Oligocene, a period that lasted 11 million years until about 23 million years ago and when mammals including prehistoric elephants, horses and deer roamed.
As well as the “slender” skull, the mammal’s jawbone and atlas were found in the Linxia Basin in Gansu province, which sits on the northeastern border of the Tibetan Plateau.
The study, published in the Communications Biology journal on Thursday, said the newly discovered species has a larger body size than other extinct hornless giant rhino, but didn’t give any indications as to its size.
Previous giant rhino fossils suggest that they once stood on four skinny legs at a shoulder height of about 4.8 metres (15.7 feet) – roughly the size of today’s largest giraffes, according to science news website ScienceAlert. Rhinos today are around 2 metres tall.
But estimates of the ancient giant rhino’s mass make it clear that if it was still around it would win any duel with a modern rhino.
Today’s rhinos weigh up to 2,400 kilograms, or 2.4 tonnes. The extinct giant rhino could have had a mass from anywhere between 11 to 20 tonnes, or roughly the same as three to five African elephants, according to ScienceAlert.
The giant rhino lived mainly in Asia, particularly in China, Mongolia, Kazakhstan and Pakistan. It is considered to be one of the largest land mammals that ever roamed on Earth, and its skull and legs are longer than those of other reported land mammals.