Dwarf elephants lived on the Mediterranean islands 800,000 years ago when their relatives became giants

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

Scientists have long debated whether these fossils of elephants of different sizes found in Europe and Asia were all the same or belonged to two or more species.

In addition to their large variations in size, prehistoric elephants, known as Palaeoloxodon, had distinctive skull ridges, bone ridges protruding around their foreheads.

An international team of researchers has studied variations on these bulging crest of the skull to classify the evolutionary history of animals with straight fangs.

While the first fossils found in India had clearly thick cranial ridges compared to those found in Europe, suggesting that they were actually separate species, the later discovery of Palaeoloxodon skulls with thick crests in Europe clouded the waters.

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

“Even in European skulls with fairly pronounced ridges, the skull roof never becomes as thick as in Indian specimens,” said article author and independent researcher Asier Larramendi of EoFauna Scientific Research in Spain.

“This tells us that we once had two separate species of these huge elephants in Europe and India.”

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Prehistoric 'dwarf' elephants the size of small donkeys once toured islands in the Mediterranean while their relative became giants with 'grotesque' bulging heads. In the picture, an artist's impression of two ancient Palaeoloxodon individuals based on fossils from Germany

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

An international team of researchers used variations on these protruding skull ridges to classify the evolutionary history of the animal with straight fangs.

An international team of researchers used variations on these protruding skull ridges to classify the evolutionary history of the animal with straight fangs.

An international team of researchers used variations on these protruding skull ridges to classify the evolutionary history of the animal with straight fangs.

When examining fossil specimens of Palaeoloxodon, Larramendi and his colleagues found that the crest of the skull was more voluminous in elephants with larger heads than smaller varieties.

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

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

“ In addition to the crest of the funky skull roof, the head of the straight fang elephant is also notable for being huge, the largest of all elephants, about 4.5 feet from the top of the skull roof to the base of the Fang pods. ” Larramendi added.

“Therefore, the crest of the skull probably evolved to provide additional fixation areas for additional neck muscles, so the animal did not fall head first.”

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

It is known that he commented that the creature’s head seemed “ so grotesquely constructed that it looks like the cartoon of the head of an elephant in a periwig, ” a reference to the helmet that was once in fashion and that some judges still wear in the present.

Paleontologists had long thought that Palaeoloxodon antiquus, the European species, had a thin crest in the skull, while Palaeoloxodon namadicus, its Indian counterpart, had an ‘extremely robust’.

But after the discovery of Palaeoloxodon skulls in Germany and Italy that presented the same exaggerated skull crests as seen in the supposed Indian form, experts began to wonder if Asian and European variants could be of a species.

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

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

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

“When we look at a series of skulls from Italy, Germany and India, we find a consistent pattern,” said Zhang

The team made a breakthrough by comparing the fossil skull scabs of the Indian and European variants of prehistoric elephants.

The team made a breakthrough by comparing the fossil skull scabs of the Indian and European variants of prehistoric elephants.

The team made a breakthrough by comparing the fossil skull scabs of the Indian and European variants of prehistoric elephants.

“When we look at a series of skulls from Italy, Germany and India, we find a consistent pattern,” said the author of the article and Earth scientist at the University of Bristol, Hanwen Zhang.

“ The crest of the skull developed from being very small, without protruding beyond the forehead in juveniles, to being larger and excelling in young adults, and eventually becoming very robust in older adults.

“Like modern elephants, Palaeoloxodon went through six sets of teeth in their lives,” he explained.

“This means that we can determine the age of any individual, with confidence, by observing their fossilized teeth.”

Scientists had long debated whether elephant fossils of different sizes represented individuals of one species or two or more. In the image, the skull of an elephant with a straight fang and a model reconstruction of what it would look like during life

Scientists had long debated whether elephant fossils of different sizes represented individuals of one species or two or more. In the image, the skull of an elephant with a straight fang and a model reconstruction of what it would look like during life

Scientists had long debated whether elephant fossils of different sizes represented individuals of one species or two or more. In the image, the skull of an elephant with a straight fang and a model reconstruction of what it would look like during life

“Even in European skulls with fairly pronounced ridges, the skull roof never becomes as thick as in Indian specimens,” said article author and independent researcher Asier Larramendi of EoFauna Scientific Research in Spain.

The researchers were able to go further with their findings than confirm two different species, Zhang added.

“Having reached the bottom of the antiquarian / namadicus problem, it became clear that other fossil materials of the skull found in Asia and East Africa represent distinct, possibly more evolutionary, conservative species of Palaeoloxodon,” he said.

“It was divided into many species, with different types in Japan, Central Asia and Europe, including some dwarf shapes as large as a small donkey in some Mediterranean islands.”

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

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