- Scientists unearthed 25 skeletons dating back as far as 12,000 years ago
- Eleven of the skulls had artificially elongated brain cases and flattened bones
- Researchers know that five belonged to adults with four men and one woman
- Cranial modification, or skull stretching, was to signify group affiliation or social status, according to the researchers
Excavation of ancient Chinese tombs have revealed the oldest human skulls which were intentionally reshaped as part of a ritual to show status and wealth.
At a site called Houtaomuga, scientists unearthed 25 skeletons dating to between 5,000 and 12,000 years ago and 11 had the egg-shaped craniums.
The practice of skull elongation - to signify group affiliation or social status - originally was thought to date back between 9,000 and 10,000 years.
It was common in various tribal cultures around the world, such as the Mayans, North American natives and Aboriginal people.
The team, from Texas A&M University in Dallas, say five of the skulls belonged to adults, including four men and one woman.
The ages of death for all 11 skulls is estimated to range from three years old right up to 40.
According to the study, skull reshaping was reserved for high-status individuals and certain families.
The three-year-old with the elongated skull was buried with pieces of pottery and other artefacts, suggesting he was from a wealthy family.
The woman had a number of shell ornaments placed on her body, which indicates she was also of high status.
'It is too early to tell whether intentional cranial modification first emerged in East Asia and spread elsewhere or originated independently in different places,' paleoanthropologist Qian Wang.
Cranial modification, or skull stretching, occurred over a long stretch of time at the site than at any other archaeological dig the researchers said.
Skull stretching it isn't a new phenomenon. The head moulding styles fell into three groups: flat, round or conical.
Specific head modifications may have been used as signs of social status.
Oddly shaped, intentionally stretched skulls have been found in many parts of the world.
Permanent reshaping of a skull early in life, when cranial bones are soft, can be achieved by compressing an infant's head with one's hands.
Binding the head with hard, flat surfaces such as boards or tightly wrapping the head in cloth similarly remodels immature cranial bones.
Houtaomuga was excavated from 2011 to 2015 and the skulls found a the site add to a growing body of evidence of cranial reshaping from the site which stretches back 6,000 years, the study said.
A man's skeleton with a modified skull was found in a tomb dating to between 13,000 and 11,000 years ago, based on styles of pottery found in the same sediment layer.
Radiocarbon dating of the skeleton placed it at around 12,000 years old. Two sediment layers dating to between 6,300 and 5,000 years old contained 10 skeletons with reshaped skulls.
The research was published in the Journal of Physical Anthropology.
HOW DID ANCIENT CIVILISATIONS MODIFY SKULLS?
The practice of skull elongation - to signify group affiliation or social status - dates back 9,000 years
Common in various tribal cultures around the world (such as Mayans, North American natives and Australian Aboriginal people), the head moulding styles fell into three groups: flat, round or conical.
To achieve the desired shape, the head was wrapped in tight cloth.
In the case of cranial flattening, the head was placed between two pieces of wood.
The technique would usually be carried out on an infant, when the skull is at its most pliable.
The cloth would be applied from a month after birth and be held in place for about six months.
Sometimes, skulls were modified as a sign of social status.
For example, ancient Collagua people, who lived in the Colca Valley of southeastern Peru, likely modified the heads of babies using bandages or special hats, in order to elongate their heads.
Analyses of skull and bone specimens dating from 1150 to 1450 indicate that those with elongated skulls had broader diets as well as fewer signs of physical attacks perpetrated against them.