Mysterious circles of bones made from the remains of dozens of mammoths have helped scientists understand how humans survived the last Ice Age. The bones at one site in Russia were found to be about 25,000 years old, according to a new analysis.
     A total of 51 lower jaws and 64 individual mammoth skulls were used to construct the walls of the 9 by 9m (30ft by 30ft) structure. A small number of reindeer, horse, bear, wolf, red fox and arctic fox bones were also found. Researchers said the bones were most likely sourced from animal graveyards.
     Archaeologists from the University of Exeter found the remains of charred wood and other soft non-woody plant remains within the structure, which is located near the modern village of Kostenki, around 500km south of Moscow.
     Mammoth-bone buildings are well-known to archaeologists. Similar structures have been found across Eastern Europe, albeit on a much smaller scale, a few meters in diameter. These sites, including others found at Kostenki during the 1950s and '60s, date back as far as 22,000 years. Researchers have generally considered them to be dwellings or 'mammoth houses' that helped their builders cope with frigid temperatures near the nadir of the last Ice Age. The new structure (first discovered at Kostenki in 2014) is 3,000 years older.
     The Kostenki 11 site stands out most obviously for its scale. "The size of the structure makes it exceptional among its kind, and building it would have been time-consuming," says Marjolein Bosch, a zooarchaeologist at the University of Cambridge. "This implies that it was meant to last, perhaps as a landmark, a meeting place, a place of ceremonial importance, or a place to return to when the conditions grew so harsh that shelter was needed."
     The astounding assemblage of bones from more than 60 mammoths raises the question: Where did they all come from? Scientists aren't sure if the animals were hunted, scavenged from sites of mass deaths or some combination of the two.
     Dr Alexander Pryor, who led the study, said: "Kostenki 11 represents a rare example of Palaeolithic hunter-gatherers living on in this harsh environment. What might have brought ancient hunter gatherers to this site? One possibility is that the mammoths and humans could have come to the area en masse because it had a natural spring that would have provided unfrozen liquid water throughout the winter - rare in this period of extreme cold."
     Most communities fled the region, likely due to a lack of prety to hunt and scarce plant resources they depeneded upon for survival, the scientists said. The bone circles, of which more than 70 are known to exist in Ukraine and the west Russian planes, were eventually abandoned as the climate grew colder and more inhospitable.
     
Edited from Smithsonian Magazine (16 March 2020), The Independent (17 March 2020)