A skull that's more than three and a half millennia old has revealed signs of an early form of brain surgery.

The perforated skull belongs to a mummified woman found in the Xiaohe tomb in China's Xinjiang Uygur Autonomous Region.

Experts said that the hole, which measures around 2 inches (50mm) in diameter, was most likely an early form of craniotomy.

The perforated skull (pictured) was discovered as part of a mummified body of a woman in the 'Little River' Xiaohe tomb complex. Experts said that the hole, measuring around 2 inches (50mm) in diameter, was most likely an early form of craniotomy - a procedure that involves removing bone to get access to the brain

A craniotomy involves temporarily removing a 'flap' of bone from the skull to give surgeons access to the brain.

The amount of skull removed depends on the type of surgery being performed, and the flap is later replaced using screws.

It may have also been a form of trepanation, which involves the removal of a piece of bone from the skull.

This procedure has been performed since prehistoric times, and cave paintings indicate that ancient people believed the practice would cure epileptic seizures, headaches and mental disorders.

The wound suggests that the female (pictured), who died in her 40s, must have lived for at least a month, or even longer, after receiving the surgery

Lead archaeologist Zhu Hong who made the discovery said: '[The wound] suggests the female, who died in her 40s, must have lived for at least a month, or even longer, after receiving the surgery.'

He added there were also signs of healing tissues around the wound.

The mummy dates back to 1,615 BC and is one of hundreds discovered in the Xiaohe 'Little River' Tomb complex.

Lying 108 miles (175 km) west of the ancient city of Loulan, the site was first explored in 1934 by Swedish archaeologist Folke Bergman, but not fully excavated until 2005.

Dating of the area has shown it goes back to approximately 2,000 BC, although tests have revealed the bodies contain DNA from the east and west.

In particular, males were found to have chromosomes typically found in Northern and Eastern Europe, alongside DNA found in Siberia.

The massive burial site has more than 330 graves and contains the largest number of mummies ever found in the world.

These tombs include adults and children as well as 15 intact mummies, although approximately half of the tombs were said to have been looted by grave robbers.

The majority of the coffins found on the site were made of wood, and were shaped like boats, buried upside down.

The mummy dates back to 1,615 BC and is one of hundreds discovered in the Xiaohe 'Little River' Tomb complex in China's Xinjiang Uygur Autonomous Region (pictured left). Lying 108 miles (175 km) west of the ancient city of Loulan, the site was first explored in 1934 by Swedish archaeologist Folke Bergman

The massive burial site has more than 330 graves and contains the largest number of mummies ever found in the world. These tombs include adults and children as well as 15 intact mummies. The majority of the coffins found on the site were made of wood, and were shaped like boats (pictured) buried upside down

WHAT IS TREPANATION? Trepanation involves the removal of a piece of bone from the skull, and it has been performed since prehistoric times. Cave paintings indicate that people believed the practice would cure epileptic seizures, headaches and mental disorders. The oldest samples of skulls with bore holes drilled into them were found in a burial site in France dating back to 6500 BC. But it was also used by the Ancient Egyptians, Chinese, Indians, Romans, Greeks and the early Mesoamerican civilizations. Even the 'father of medicine' Hippocrates advocated the process in his 400 BC tome 'On Injuries of the Head'. Modern exponents say it increases blood flow in the brain, increasing lucidity and heightening brain function. Advertisement

This practice is similar to how the Egyptians believed boats would take Pharaohs to the land of the ‘Gods’

Clothes and jewellery found in the tomb were also buried alongside the mummies, in small baskets, and the bodies were wrapped in cowhide and wool.

This prevented sand from getting inside the corpses.

In addition to the wood coffins, four clay-covered rectangular coffins were also found, surrounded by stakes.

And six of the coffins were found to contain wooden 'bodies', rather than corpses.

Each of these wooden sculptures were the same shape and were designed to look like males.

Sexual iconography was everywhere at the site, with posts representing phalluses and vulvas placed in front of each grave.

Last week, scientists recreated ancient brain surgery to understand medical techniques that existed almost 2,500 years ago.

A team of experts in Russia spent the past year examining skulls found with intricate surgical holes in a bid to fathom out how early nomadic doctors carried out their work.

This practice is similar to how the Egyptians believed boats would take Pharaohs to the land of the ‘Gods’. Clothes and jewellery found in the tomb were also buried alongside the mummies, in small baskets, and the bodies (pictured) were wrapped in cowhide and wool. This prevented sand from getting inside the corpses

Last week, scientists recreated ancient brain surgery on a modern skull (shown) to understand medical techniques that existed almost 2,500 years ago. A team of experts in Russia spent the past year examining skulls found with intricate surgical holes in a bid to fathom out how early nomadic doctors worked

Evidence from ancient skulls (pictured) suggest they are among the earliest ever examples of trepanation - an ancient form of neurosurgery

Evidence suggested they were among the earliest ever examples of trepanation - the oldest form of known neurosurgery - with the procedures skilfully carried out.

The oldest samples of skulls with bore holes drilled into them were found in a burial site in France dating back to 6500 BC.

But it was also used by the Ancient Egyptians, Chinese, Indians, Romans, Greeks and the early Mesoamerican civilisations.

Even the 'father of medicine' Hippocrates advocated the process in his 400 BC tome 'On Injuries of the Head'.

The procedure was carried out by Aleksei Krivoshapkin according to ancient methods used in the Altai Mountains on the skull of a woman who had died of natural causes shortly before.