Giant rhino that once roamed China may be ‘largest land mammal’ that ever lived
A giant rhino dug up in China could be ‘the largest land mammal’ that ever lived, say scientists.
The colossal creature was more than 26 feet long, over 16 foot tall and weighed 24 tonnes.
It was four times the size of an African elephant – the biggest animal that walks the Earth today.
The hornless herbivore roamed Asia 26.5 million years ago – browsing the forests for leaves, soft plants and shrubs.
It resembled an overgrown tapir – and has been named Paraceratherium linxiaense. The bizarre animal had a slender skull, short trunk and an unusually long and muscular neck.
The discovery sheds fresh light on how the friendly giants migrated across continents.
On the way they faced prehistoric hyenas and giant crocodiles – and endured the frigid wilderness of the Ice Age.
Lead author Professor Tao Deng, of the Chinese Academy of Sciences, Beijing, said: ‘It had a body weight of 24 tonnes, similar to the total weight of four African elephant or eight white rhinos.
‘It was five metres (16.4ft) high at the shoulders and 8 metres (26.25ft) long). The giant rhino’s long legs were good for running. Its head can reach a height of 7 metres (23ft) to browse leaves of tree tops.
‘Its prehensile nose trunk was extremely useful to wrap around branches – allowing the sharp front teeth to strip off the leaves.
‘Its tusk-like incisors are primarily used to break twigs and strip bark, as well as to bend higher branches.’
The skull and legs are longer than all reported land mammals. The animal was suited to open woodlands under humid or arid conditions.
Paraceratherium was identified from a perfectly preserved skull, jaw and atlas – the first cervical vertebra of the spine that supports the head.
The fossilised remains were dug up at a prehistoric animal graveyard in Gansu, north western China.
Giant rhino specimens are scarce – and most are fragments. These are among the best found – and help fill an important branch in the beast’s family tree.
Prof Deng said: ‘It is one of the largest land mammals that ever lived. The giant rhino has primarily been found in Asia. But its evolutionary relationships remain unclear.
‘This animal has distinct characters – a slender skull with a short nose trunk and long neck, and a deeper nasal cavity than other giant rhino species.’
Paraceratherium, described in the journal Communications Biology, is closely related to the giant rhinos of Pakistan.
Prof Deng said: ‘It raises the possibility the giant rhino could have passed through the Tibetan region before it became the elevated plateau it is today.
‘From there, it may have reached the Indian-Pakistani subcontinent in the Oligocene epoch between 34 and 23 millions years ago where other giant rhino specimens have been found.’
The giant rhino is one of the most iconic Ice Age beasts – wiped out by climate change, disease and human hunting. But its origins are a mystery.
Prof Deng said: ‘The Tibetan region likely hosted some areas with low elevation, possibly under 6,500ft during Oligocene.
‘The lineage of giant rhinos could have dispersed freely along the eastern coast of the Tethys Ocean and perhaps through some lowlands of this region.’
The rock that forms the Himalayas was once submerged by the ancient sea.
Giant rhino remains found have been found in Eastern Europe. But they mainly lived in China, Mongolia, Kazakhstan, and Pakistan.
Prof Deng said: ‘During the Oligocene, dispersal for the giant rhino from the Mongolian Plateau to South Asia could have been along theeastern coast of the Tethys like other mammals, such as anthracotheres and ruminants.’
It adds to evidence the Tibetan region was not yet the elevated plateau it is today, without height great enough to deter the giant rhino and other great mammals.
The possibility is supported by other evidence. Fish and plant fossils dating back to the same period from central Tibet display tropical characteristics – indicating low elevation.
Prof Deng added: ‘Through to the late Oligocene, the evolution and dispersal of the giant rhino demonstrate Tibet, as a plateau, did not exist and was not yet a barrier to the largest land mammals.’
Paraceratherium would have been majestic – even compared to the amazing mammal faunas of Eurasia between 35 and 20 million years ago.
Its vertical reach enables it to eat food at the top of the canopy – uunlike the modern elephant’s method of extending a flexible trunk.
The arrival of a different kind of herbivore might have triggered ecological changes that helped drive the rhinos to extinction.
At the time tropical forests were shrinking and grassy savannahs were spreading. The lush grasslands suited giant rhinos down to the ground.
Rhinos belong to a group of animals called perissodactyls. They have hooves – and an odd number of toes on their rear feet. It is believed they first appeared 55 million years ago in India – which at the time was not attached to Asia.
Perissodactyls were the ancestors of today’s rhinos – as well as all modern horses, zebras and tapirs.