2,300-year-old bones of an extinct gibbon kept as a pet by 'femme fatale' Lady Xia, the grandmother to China’s first emperor, are found in her burial chamber

• Researchers made 3D computer models of a skull to compare it with others
• It was found to be different from all four living branches of the gibbon family 
• The species is believed to have survived until as recently as 300 years ago
• Global decline in ape species may have begun earlier than thought, experts say

Ancient bones belonging to a newly discovered but now extinct species of gibbon have been found alongside remains thought to be those of Chinese royalty.

Experts came across the creature's bones while exploring a tomb believed to belong to 'femme fatale' Lady Xia, the grandmother to China’s first emperor. 

Legends of the woman speak of her devastating beauty, which was the cause of numerous wars and other disputes among states.

Her tomb, dating back 2,300 years, may seem like a strange place for such a discovery, but gibbons have played a key role in Chinese culture for millennia.

They feature heavily in literature and art and were seen as noble, with the gibbon in question likely to have been kept as a high status pet by Lady Xia.

Despite this venerated status, this particular species likely became extinct due to human activities like hunting and deforestation in the relatively recent past.

This may suggest that the current global decline in the number of ape species may have begun earlier than had been assumed, researchers claim.

Ancient bones belonging to a newly discovered but now extinct species of gibbon have been found alongside remains thought to be those of Chinese royalty. This image shows a skull fragment recovered from the tomb 

The discovery was made by scientists led by international conservation charity the Zoological Society of London (ZSL).

The tomb, first excavated in 2004 and located in the old capital of Chang'an, was found to contain 12 burial pits with animal remains, which included gibbon bones.

Sophisticated computer modelling has now revealed that these ancient bones represent an entirely new genus and species of gibbon.

Historical records reveal that Junzi imperialis, named for its royal connection, probably survived until as recently as 300 years ago.

It represents the first documented evidence of an ape extinction since the last ice-age.

Experts made 3D computer models of this skull fragment and from skulls found in museum collections in China, Vietnam and across Europe. They compared these to the gibbon found in the tomb using statistical analysis called morphometrics that measures differences in shape

The gibbon skull from the tomb was found to be different from all four living branches of the gibbon family, on the basis of both cranial and dental morphometrics. This demonstrates that this gibbon is distinct at the genus level from all living gibbons, experts say

All of the world’s apes - chimpanzees, gorillas, orang-utans and gibbons - are threatened with extinction today due to human activities, but no ape species were thought to have become extinct as a result of historic hunting or habitat loss. 

However, the discovery of the recently extinct Junzi changes this, and highlights the vulnerability of gibbons in particular, researchers say.

Speaking to MailOnline, Dr James Hansford from ZSL, who was involved the research, said: 'Until the discovery and description of Junzi imperialis, it was thought that apes and most other primates have been relatively resilient to past human pressures on biodiversity.

'As a result, it was assumed that the worrying global decline of apes was a modern-day phenomenon.

'We're now realising that there may also have been numerous past human-caused extinctions of apes and other primates before the recent historical era.'

Chinese archaeologists uncovered a semi-complete gibbon skull, mandible, and skeleton when exploring the tomb of Lady Xia.

ZSL experts made 3D computer models of this skull fragment and from skulls found in museum collections in China, Vietnam and across Europe.

They compared these to the gibbon found in the tomb using statistical analysis called morphometrics that measures differences in shape.  

The gibbon skull from the tomb was found to be different from all four living branches of the gibbon family, on the basis of both cranial and dental morphometrics.

The Hainan gibbon, scientific name Nomascus hainanus (pictured), a species of gibbon found on Hainan Island in southern China, is now probably the world’s rarest mammal, with only 26 surviving individuals

This demonstrates that this gibbon is distinct at the genus level from all living gibbons, making it only the eighth known ape genus to have survived into the recent historical era, researchers say.

Eastern and Southeast Asia are currently home to some of the world’s most threatened mammals, with 73 per cent of Asian primates being threatened, compared to 60 per cent globally. 

Two species of gibbon have recently disappeared in China, and all surviving Chinese species are currently classified as Critically Endangered by the IUCN’s Red List of Threatened Species. 

The Hainan gibbon, scientific name Nomascus hainanus, a species of gibbon found on Hainan Island in southern China, is now probably the world’s rarest mammal, with only 26 surviving individuals.   

Junzi imperialis was found in a region not populated by gibbons today, making its discovery all the more unlikely.

Speaking to MailOnline, Dr Hansford added: 'Finding this specimen so far away from their known habitat ranges today is extraordinary.

'It is also incredibly rare to find such an intact primate skull in the archaeological and palaenotological record. 

'Add the fact that this was found in an Imperial tomb and this makes for a world-class find.'

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

The discovery was made by scientists led by international conservation charity the Zoological Society of London. The tomb, first excavated in 2004 and located in the old capital of Chang'an, was found to contain 12 burial pits with animal remains