A family of four mammoth skeletons, including a rare infant, are expected to fetch up to £400,000 ($530,000) at an auction in Sussex later this year.
The remains of a small herd of ice age giants, believed to be between 12,000 and 16,000 years old, were uncovered by construction workers in Siberia.
The remarkably preserved infant is only the second complete baby mammoth skeleton to be found in the world.
Scroll down for video
Now collectors and museums are being offered the chance to get their hands on the unique set of remains, in the first time a complete family has gone up for auction.
Experts believe the group were killed in a natural disaster after their skeletons were found to show no signs of hunting scars.
The family consists of a male and female mammoth, an adolescent daughter and a one-year-old infant.
Bidding will start at £250,000 ($330,000) for the ancient beasts at Summers Place Auctions in Billingshurst, West Sussex, on November 21.
Rupert van der Werff, Summers Place Auctions’ Natural History specialist, said: ‘I was really excited to see the mammoths as a group for the first time a few months ago, but it was quite a thrill when they arrived in 16 boxes in our gallery in Billingshurst.
‘Building’ a skeleton comes with a lot of challenges, imagine it to be a bit like doing a rather difficult 3D puzzle.
‘Having sold an individual mammoth in 2014 for £150,000 ($200,000), we hope that this unique family group will find a new home in a museum, a company’s atrium or a private collection somewhere around the world.’
The remains were spotted near a river bed by builders in the Siberian city of Tomsk, in the south-west of the great Siberian Taiga in 2002.
Although the adult female was over 2 metres (6.5 ft) tall and is estimated to have weighed around 2.8 tonnes, she is relatively small for a mammoth.
This leads experts to conclude the family had been living in unfavourable conditions towards the end of the Pleistocene period – some 12,000 to 16,000 years ago.
Tooth wear indicates the female was 45 years old, while the younger female is thought to have been just eight or nine.
The highlight of the group is the incredibly rare one-year-old skeleton.
Experts detected its 3rd and 4th vertebrae were fused and the long leg bones were not yet fully ossified, nor completely fused.
As there is no damage to indicate human hunting and the bones were found in fluvial deposits, the mass grave was likely the result of a natural phenomenon.
Errol Fuller, Summers Place Auctions’ Natural History curator and author of several books on mammoths, said: ‘The mammoth has always been a herd animal, so the discovery of this family is simply the perfect representation of this species.
‘About 20,000 years ago the great herds that had roamed across vast areas of Europe, Asia and North America started to dwindle to localised bands of animals, which also started to reduce in physical size.
‘So this family seems to be a prime example of the extinction of the mammoth through climate change and human intervention.’
The woolly mammoth roamed the icy tundra of Europe and North America for 140,000 years, disappearing at the end of the Pleistocene period, 10,000 years ago.
They are one of the best understood prehistoric animals known to science because their remains are often not fossilised but frozen and preserved.
Males were around 12 feet (3.5m) tall, while the females were slightly smaller.
Curved tusks were up to 16 feet (5m) long and their underbellies boasted a coat of shaggy hair up to 3 feet (1m) long.
Tiny ears and short tails prevented vital body heat being lost.
Their trunks had ‘two fingers’ at the end to help them pluck grass, twigs and other vegetation.
They get their name from the Russian ‘mammut’, or earth mole, as it was believed the animals lived underground and died on contact with light – explaining why they were always found dead and half-buried.
Their bones were once believed to have belonged to extinct races of giants.
Woolly mammoths and modern-day elephants are closely related, sharing 99.4 per cent of their genes.
The two species took separate evolutionary paths six million years ago, at about the same time humans and chimpanzees went their own way.
Woolly mammoths co-existed with early humans, who hunted them for food and used their bones and tusks for making weapons and art.