Ancient humans dined out by eating the massive heads of now extinct elephants.

According to new research, people living in Palaeolithic times, commonly known as the Stone Age, hunted elephants as a valuable source of food.

Carnivory has been a human trait from our earliest stage to today

As well as eating their bodies, they made the most of the animals’ huge heads.

They scooped out and ate the elephants’ brains, but also their trunks, tongues, glands, and even their skulls and lower jaw bones.

That helps explain why early humans transported elephant heads with them as they travelled between sites.

The extent to which Palaeolithic humans ate elephants has been hotly debated.

It has long been accepted that early humans hunted and ate animals, as vital sources of proteins and fat.

“Carnivory has been a human trait from our earliest stage to today,” say researchers in a paper published in the journal Quaternary International.

But scientists have questioned whether elephants were too big to kill. Instead of actively hunting them, early humans might instead have scavenged the remains of dead elephants killed by age or other predators.

The head of a modern elephant may exceed 400kg

Now a new study not only concludes that elephants were hunted, but that their heads were a vital source of calories for early humans. So much so, that early humans even went to the trouble of transporting the heads around.

Aviad Agam and Ran Barkai of Tel Aviv University, Israel, reviewed a number of archaeological sites at which elephant heads have been discovered.

They included sites inhabited by early humans across the Old World, such as a 1.6 milion to 1.3 million-year-old site in what is now the Republic of Djibouti in Africa, 800,000-year-old and 500,000-year-old sites in Israel, and 150,000 to 13,000-year-old sites across modern Russia and Europe.

For example, at Gesher Benot Ya'aqov, an open-air Lower-Middle Pleistocene site located in the Dead Sea Rift valley, archaeologists have found crabs, fish, fallow deer and turtle remains, alongside those of 154 elephants, including a complete skull, a few fragments of teeth, tusks, cranium, and two pieces of the internal surface of the braincase.

Another almost complete elephant's skull was recovered from the site. Part of it had been intentionally removed and crushed by the people once living there.

These remains belonged to a now-extinct elephant species, Palaeoloxodon antiquus, known as the straight-tusked elephant.

Elephant remains, head parts included, were found inside the cave

Closely related to today’s Asian elephant, the straight-tusked elephant species was even bigger than today’s species.

They were also, by far, the largest meal that ancient humans could hunt and eat; the straight-tusked elephant that roamed Europe and Asia was five times bigger than the next largest animal alive in the area at the time; the hippopotamus.

The skull and jaw of a modern African elephant (Loxodonta africana) can weigh 180kg. The trunk another 110kg, the ears 44kg, and the tongue 14kg. The brain can reach 6.5kg. In total, the head of a modern elephant may exceed 400kg.

“These figures should be greatly enlarged, if not almost doubled, for Pleistocene extinct elephants,” say the scientists.

Containing ideal proportions of meat and fat, for ancient humans, “elephants represent an ideal food package,” they say.

Further evidence that early humans actively sought the heads of elephants comes from Bolomor cave, located in the Valldigna valley, near Valencia in modern Spain.

Inside have been found a number of ancient elephant bones, including skull and leg bones.

“It takes rigorous climbing to get to the cave,” say the researchers. “Nevertheless, elephant remains, head parts included, were found inside the cave.”

Elephants' heads were favoured by early humans as exceptionally nutritious

That suggests the nutritional value of the elephant heads was worth the great effort needed to transport them there.

The scientists also investigated how much nutrition each part of an elephant’s head may provide.

They researched accounts of how people in Africa have in recent centuries hunted and eaten elephants.

These suggest that people used to crush the skulls and jawbones of elephants to remove fat lying within its honeycomb bone structure. Fat could also be extracted from around a dead elephant’s eyes and from an organ only elephants possess, called the temporal gland, from which male elephants secrete when in musth.

The scientists cite other evidence that early humans may have similarly transported mammoth heads.

“Elephants' heads were favoured by early humans as exceptionally nutritious,” they conclude.

Early humans’ taste for elephant heads might also be evidence that these peoples cooperated when hunting, as it would have taken many individuals to move such huge objects into caves.

“The repeated evidence of transportation of elephants' head parts to residential sites indicates it was chosen to be transported back to the camp site,” say the researchers.

“It seems unlikely that the skull was acquired and brought to camp sites solely for the extraction and consumption of the brain.”

“Other head parts, such as the tongue, the temporal gland, the trunk, the mandible and the skull, were also used as a significant part of early hominins' diet.”

Matt Walker is BBC Earth's editor. He is @byMJWalker on Twitter.

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