Dwarf elephants lived on Mediterranean islands 800,000 years ago

Prehistoric ‘dwarf’ elephants the size of small donkeys roamed the Mediterranean islands 800,000 years ago while their relatives became giants with ‘grotesque’ bulging heads

  • The history of these ancient elephants has long been a puzzle for scientists
  • Those from India first seemed to have big skull crests unlike those from Europe 
  • Subsequent discoveries of big crested specimens in Europe muddied the waters
  • Comparing fossils, experts determined that the variants were different species

Prehistoric ‘dwarf’ elephants the size of small donkeys once roamed islands in the Mediterranean, while their relatives became giants with ‘grotesque’ bulging heads.

Scientists have long debated whether these different-sized elephant fossils found throughout Europe and Asia were all the same or belonged to two or more species. 

Apart from their stark size variations, the prehistoric elephants, known as Palaeoloxodon, had distinctive skull crests — ridges of bone that protruded around their foreheads.

An international team of researchers has now studied variations in these bulging skull crests to sort out the evolutionary history of the straight-tusked animals.

While the first fossils found in India had distinctively thick skull crests compared to those found in Europe, suggesting that they were indeed separate species, the later discovery of Palaeoloxodon skulls with thick skull crests in Europe muddied the waters.

However, experts have now determined that the larger Indian elephants were indeed of a different species from those with smaller skull crests.

‘Even in European skulls with quite pronounced crests, the skull roof never becomes as thickened as in the Indian specimens,’ said paper author and independent researcher Asier Larramendi, of Spain’s EoFauna Scientific Research.

‘This tells us we once had two separate species of these enormous elephants in Europe and India.’

Scroll down for video

Prehistoric ‘dwarf’ elephants the size of small donkeys once roamed islands in the Mediterranean while their relative became giants with ‘grotesque’ bulging heads. Pictured, an artist’s impression of two Palaeoloxodon antiquus individuals based on fossils from Germany

An international team of researchers used variations in these bulging skull crests to sort out the straight-tusked animal’s evolutionary history

Examining fossil Palaeoloxodon specimens, Mr Larramendi and colleagues found that the skull crest was bulkier on the larger-headed elephants than the smaller varieties. 

The team suspects that the skull crest became so huge to provide additional attachment areas for the extra neck muscles that would have been required to support the beast’s enormous head.

These could reach up to 4.5 feet (1.4 metres) in height, making them the largest elephant heads ever found.

‘Besides the funky skull roof crest, the head of the straight-tusked elephant is also remarkable for being huge, the largest of any elephant ever — some 4.5 feet from the top of the skull roof to the base of the tusk sheaths,’ Mr Larramendi added.

‘Therefore, the skull crest probably evolved to provide additional attachment areas for extra neck muscles, so the animal did not fall on its head.’

The first fossil Palaeoloxodon skull to be found was unearthed in India, and studied by the Victorian Scottish geologist Hugh Falconer in the 1840s.

He is known to have remarked that the creature’s head seemed ‘so grotesquely constructed that it looks the caricature of an elephant’s head in a periwig’ — a reference to the once-fashionable headgear still worn by some judges today.

Palaeontologists had long thought that Palaeoloxodon antiquus — the European species — had a slender skull crest, while Palaeoloxodon namadicus — it’s Indian counterpart — had an ‘extremely robust’ one.

But after the discovery of Palaeoloxodon skulls in Germany and Italy that featured the same exaggerated skull crests as seen in the supposed Indian form, experts began to question if the Asian and European variants might in fact be of one species.

The first fossil Palaeoloxodon skull to be found was unearthed in India, and studied by the Victorian Scottish geologist Hugh Falconer, pictured, in the 1840s

‘When we looked at a series of skulls from Italy, Germany and India, we found a consistent pattern,’ Mr Zhang said

The team made a breakthrough when comparing the skull crusts of fossils of the Indian and European variants of the prehistoric elephants

‘When we looked at a series of skulls from Italy, Germany and India, we found a consistent pattern,’ said paper author and University of Bristol earth scientist Hanwen Zhang.

‘The skull crest developed from being very small — not protruding beyond the forehead in juveniles — to being larger and more protruding in young adults, eventually becoming very stout in aged adults.

‘Just like modern elephants, Palaeoloxodon went through six sets of teeth in their lifetimes,’ he explained.

‘This means we can tell the age of any individual, with confidence, by looking at its fossilised teeth.’ 

Scientists had long debated whether the different-sized elephant fossils represented individuals from within one species or two or more separate ones. Pictured, the skull of a straight-tusked elephant and a model reconstruction of how it would have looked during life

‘Even in European skulls with quite pronounced crests, the skull roof never becomes as thickened as in the Indian specimens,’ said paper author and independent researcher Asier Larramendi, of Spain’s EoFauna Scientific Research. 

The researchers were able to go further with their findings than confirming two distinct species, Mr Zhang added. 

‘Having gotten to the bottom of the antiquus/namadicus problem, it then became apparent that other fossil skull materials found in Asia and East Africa represent distinct, possibly more evolutionary conservative species of Palaeoloxodon,’ he said.

‘It divided into many species, with distinct types in Japan, Central Asia and Europe — even some dwarf forms as large as a small donkey on some Mediterranean islands.’

The full findings of the study were published in the journal Quaternary Science Reviews. 

Source: Read Full Article