Somewhere in the frozen plains of southwestern Russia, a 40-foot circle of mammoth bones and tusks has stood for over 24,000 years. This is the remnant of an ancient structure made by Ice Age hunters using animal bones. Whether it served as a dwelling, a ritualistic hotspot, or some other purpose is yet unclear.

But now, a new DNA study of 39 bone samples from 30 mammoths from the Kostenki 11 site is offering new clues about how these ancient humans lived — and how they used the mammoths they hunted.

Circles of bones

The Kostenki 11 site, located near the Don River, just 300 kilometers from Moscow, is one of the most significant Upper Paleolithic sites in Europe. It contains several circular structures made from the bones of woolly mammoths, some of which are over 40 feet (12 meters) in diameter.

The site is not alone. These types of structures — more than 70 of which have been found thus far across Ukraine and western Russia — have been the subject of speculation for decades. Were they built from freshly hunted mammoths, or were the bones scavenged from long-dead carcasses?

To answer this question, an international team of researchers turned to the bones themselves. Using radiocarbon dating, ancient DNA analysis, and stable isotope studies, they pieced together the story of the mammoths — and the humans who used their remains.

A mammoth legacy

Scientists found the bones came from mammoths that died over a span of centuries. Some of the bones were from animals that had been dead for over a thousand years before they were used in the construction of the circular structures. This means that humans were not just hunting mammoths, they were also scavenging bones from older carcasses.

All mammoth bone circles are flanked by a series of large pits, which may have been used to store food or dump waste. Kostenki 11 was first discovered in 2013. For three years the researchers had been excavating the site, employing flotation — a technique that involves water and sieves to separate ancient remains and artifacts from the soil.

A total of 51 lower jaws and 64 individual mammoth skulls were used to construct the walls, according to the investigation carried out by the team of researchers led by Dr. Alexander Pryor from the University of Exeter, UK.

Just imagine how surreal it must have been living inside this dwelling made entirely of mammoth bones and skulls.

In addition to the mammoth bones, the researchers were able to find evidence of charcoal and burnt bones, stone tool fragments, and soft plant tissue that hint at the diet consumed during those times. The charcoal suggests that fires were started inside the circular structure, providing comfort in the harsh ice age nights. Climate modeling indicates that around the time the structure was erected, conditions may have been at their worst, with average temperatures around -20 degrees Celsius or lower.

The bones themselves don’t show signs of butchery. However, in the case of game of this size, the hunters probably removed the bulk of the meat, leaving small chunks to rot on the bone.

A bias for mammoth females

The study also uncovered surprising details about the mammoths themselves. By analyzing the DNA of 30 individuals, the researchers found that the majority were female. This stands in stark contrast to other mammoth sites, where males tend to dominate the fossil record. The researchers suggest that the Kostenki mammoths may have come from herds, which are typically led by matriarchs.

The researchers also identified seven distinct mitochondrial lineages among the mammoths, indicating that they were not all from the same family group. This further supports the idea that the bones were collected over a long period of time, rather than coming from a single hunting event.

By analyzing stable isotopes in the bones, the researchers were able to determine what the animals ate. Surprisingly, they found no significant differences between the diets of males and females. In modern elephants, males and females often have different foraging habits, with males tending to roam farther and eat a wider variety of plants. The lack of such differences in mammoths suggests that their social structure and behavior may have been quite different from that of their modern relatives.

A Window into the Ice Age

The fact that the bones were collected over centuries suggests that the circular structures were not built in a single event but were instead the result of long-term, repeated use. This means the area was constantly habitable, although not maybe year-round. The conventional picture of hunter-gatherer groups in constant motion, looking for new opportunities to forage and hunt in new territories is becoming increasingly outdated. While these people were surely on the move, they likely operated around important landmarks that served as bases or ceremonial gathering places, especially during astronomical events like equinoxes and solstices.

As the frozen plains of Russia continue to yield their secrets, the mammoth bones of Kostenki 11 stand as a testament to the ingenuity and resilience of our ancient ancestors. In a world of ice and snow, they found a way to survive—and to leave their mark on the landscape for millennia to come.

The new findings appeared in the journal Quaternary Environments and Humans.