Archaeologists have uncovered what may be the world’s first murder - dating back 430,000 years.

Researchers say lethal wounds identified on a human skull in Spain are likely to be evidence of the first case of homicide in human history.

And they concluded that the primitive man was killed by two blows to the head just above his left eye using the same object.

The nearly complete skull (pictured top left) was found at Sima de los Huesos in Spain. It shows two penetrating lesions on the frontal bone, above the left eye (T1 and T2). Using modern forensic techniques the authors believe both fractures were likely produced by two separate impacts by the same object

The archaeological site, Sima de los Huesos in northern Spain, is located deep within an underground cave system and contains the skeletal remains of at least 28 people.

An almost complete skull of 52 fragments was recovered during excavations over the past 20 years and it has been pieced together with remarkable results.

In particular, the scientists found that two clear fractures at the front of the skull were likely to have been deliberately caused by another primitive human.

Study leader Dr Nohemi Sala said: ‘This skull shows two penetrating lesions on the frontal bone, above the left eye.’

Relying on modern forensic techniques, the researchers showed that both fractures were most likely produced by two separate blows by the same object.

The archaeological site is located deep within an underground cave system (illustrated left) and contains the skeletal remains of at least 28 people. The almost complete skull was made up of 52 fragments that had been recovered during excavations over the past 20 years and pieced together (fragments pictured right)

The only access to the site is through a 43ft (13 metre) shaft and how the bodies arrived there remains a mystery. But the researchers said the injuries (marked in red and green) are unlikely to be the result of an accidental fall and are instead evidence of an act of aggression - the earliest case of murder in human history

The only access to the site is through a 43ft (13 metre) deep vertical shaft, and how the human bodies arrived there remains a mystery.

But the researchers, whose findings are published in the journal Plos One, said the injuries are unlikely to be the result of an accidental fall down this shaft.

The Atapuerca Mountains, where the skulls were unearthed, is in the Spanish province of Burgos and near Atapuerca and Ibeas de Juarros

Instead, they interpreted them as evidence of an act of lethal aggression - or what may constitute the earliest case of murder in human history.

Dr Sala said if the person was already dead, they would have been carried to the top of the vertical shaft by other humans.

And the authors suggest fellow humans were likely responsible for the accumulation of bodies in the Sima de los Huesos.

The cave, known as the ‘Pit of Bones’, is one of the richest sources of prehistoric fossils in Europe.

In 2013, scientists extracted the oldest ever human DNA from the fossilised leg bone of an early human laid to rest at the same site.

The primitive human died approximately 400,000 years ago.

Its DNA sequences proves it was more closely related to an even earlier human species living in Siberia about 700,000 years ago than to the European Neanderthals who thrived until 30,000 years ago.

An analysis of remains discovered at the site last year additionally found that early Neanderthal man used his mouth as a ‘third hand’.

The cave, known as the ‘Pit of Bones’, is one of the richest sources of prehistoric fossils in Europe. This GIF shows shows the reconstructed skull from various angles

The discovery of the skull (pictured) at the Sima de los Huesos site in Spain's Atapuerca Mountains also allows scientists to better understand pre-human evolution during the Middle Pleistocene period - a time in which the path of hominin evolution has been controversial and fiercely debated

This study bolsters theories that Neanderthals evolved their characteristic looks slowly and intermittently, over hundreds of thousands of years.

For example, analysis of a collection of skulls in the Spanish cave suggested the predecessors of Neanderthals used their teeth as a vice for tearing meat and carrying objects.

NEANDERTHALS 'GENES' MAY BE TO BLAME FOR MODERN DISEASES Neanderthals and modern humans are thought to have co-existed for thousands of years and interbred. These 'legacy' genes have been linked to an increased risk from cancer and diabetes by new studies looking at our evolutionary history. However, it is not all bad news, as other genes we inherited from our species' early life could have improved our immunity to diseases which were common at the time, helping humans to survive. Speaking to MailOnline, professor Chris Stringer, research leader in human origins at the Natural History Museum in London, said: 'We got a quick fix to our own immune system by breeding with Neanderthals which helped us to survive. 'Studies have also already been published which show that humans outside of Africa are more vulnerable to Type 2 diabetes, and that is because we bred with Neanderthals, while those who stayed inside Africa didn't.' Last year researchers from Oxford and Plymouth universities announced that genes thought to be risk factors in cancer had been discovered in the Neanderthal genome, and in January Nature magazine published a paper from Harvard Medical School suggesting that a gene which can cause diabetes in Latin Americans came from Neanderthals. Advertisement

The ancient skulls show Neanderthal-like features in the face and teeth, while other parts of the skulls, including the brain case, resembled those of more primitive human ancestors.

This suggests the earliest Neanderthals used their jaws in a particular way for chewing as well as for holding objects.

The discovery at the Sima de los Huesos site in Spain's Atapuerca Mountains has allowed scientists to better understand pre-human evolution during the Middle Pleistocene period - a time in which the path of hominin evolution has been controversial and fiercely debated.

Juan-Luis Arsuaga, a paleontologist at the Complutense University of Madrid was involved in both the 2014 study and the most recent research.

He claims the findings are consistent with a 'Game of Thrones' evolutionary saga.

In this scenario, communities of humans, equivalent to 'houses' in the fantasy series, competed for habitable areas more than 400,000 years ago.

'The Middle Pleistocene was a long period, of about half a million years, during which hominin evolution didn’t proceed through a slow process of change with just one kind of hominin quietly evolving towards the classic Neanderthal,’ he said.

Co-author of the study Ignacio Martinez, Professor of Paleontology at the University of Alcalá, added: ‘With the skulls we found it was possible to characterise the cranial morphology of a human population of the European Middle Pleistocene for the first time.’

Around 400,000 to 500,000 years ago, archaic humans split off from other groups of that period living in Africa and East Asia, ultimately settling in Eurasia.

Once settled, they evolved characteristics that would come to define the Neanderthal lineage.

Several hundred thousand years later, modern humans - who had evolved in Africa - settled in Eurasia.

Pictured is the discovery of the skull, known as cranium 17, in the 'Pit of Bones'. Ignacio Martinez, Professor of Paleontology at the University of Alcalá, said: 'With the skulls we found it was possible to characterise the cranial morphology of a human population of the European Middle Pleistocene for the first time' The ancient skulls (a specimen pictured) show a mix of Neanderthal and more primitive traits, suggesting Neanderthals evolved their defining characteristics in stages. This so-called 'mosaic pattern' of development supports a theory of Neanderthal evolution that suggests they developed their features separately

They interbred with the Neanderthals, but showed signs of reproductive incompatibility. Because of this, modern humans eventually replaced Neanderthals.

The degree of divergence between Neanderthals and modern humans over such a short period of time has long puzzled scientists.

It has, until now, been difficult to fill in the gaps because the European fossil record is isolated and dispersed. However, samples at the Sima de los Huesos site are different.

Professor Arsuaga added: ‘What makes the Sima de los Huesos site unique is the extraordinary and unprecedented accumulation of hominin fossils there; nothing quite so big has ever been discovered for any extinct hominin species-including Neanderthals.

‘After 30 years, we have recovered nearly 7,000 human fossils corresponding to all skeletal regions of at least 28 individuals.

'This extraordinary collection includes 17 fragmentary skulls, many of which are very complete.’

The 17 skulls belong to a single population of a fossil hominin species. Some of have been studied before, but seven are presented anew here, and six are more complete than ever before.