The Russian Academy of Sciences and the University of Colorado at Boulder, and including Vance T. Holliday, a UA professor of anthropology and geosciences, excavated three and worked on six of the more than two dozen ancient sites along the Don River, about 240 miles south of Moscow, Russia. Their discovery is published in the current (Jan. 12) issue of the journal Science ("Early Upper Paleolithic in Eastern Europe and Implications for the Dispersal of Modern Humans").
The excavations are located in the villages of Kostenki and Borshchevo, on the low terraces just above the Don River, overlooking a broad valley. Holliday says the uplands at Kostenki closely resemble rural Iowa. The area also has a number of natural springs and seeps that would have been an important source of fresh water for both the humans and the animals they hunted.
While there is little human skeletal evidence except for a few teeth, other artifacts found at Kostenki - including stone tools and elegant beadwork and figurines made from shells and ivory - are consistent with Upper Paleolithic humans. Stone used for tools were imported from quarries at least 60 miles away. The animal remains on site indicate that these people were technologically adept at hunting a variety of small and large game - hares, foxes, birds, fish and a number of very large animals, including mammoth.
The notion that modern people lived that long ago in what was then a sub-Arctic region intrigued Holliday, who analyzed the stratigraphy of the sites. Some of the digs are several meters deep in places, covered by silt from centuries of repeated flooding. Bones and artifacts have been exposed there for centuries, and scientific archaeology missions have dug there since 1879.
Getting a precise fix on the age of the sites is a bit complicated. Radiocarbon dating and a technique called OSL, or optically stimulated luminescence - measuring the time an artifact was last exposed to sunlight - offer varying levels of certainty.
But Holliday says the key is a thin layer of volcanic ash overlaying the oldest modern sites. The ash deposit is evidence of a very large volcanic eruption known to have occurred in Italy about 40,000 years ago, guaranteeing that anything underneath is older.
"OSL goes back much farther than C14, but it isn't as reliable as C14, so the ash provide a nice check on the OSL dates from levels beyond the reliability of C14 as well as being a superb marker bed and dating tool in its own right," Holliday says.
There are older deposits of artifacts below the settlements created by humans, likely belonging to Neanderthals, although no skeletal evidence of them remains either. Neanderthals roamed across Ice Age Europe for 200,000 years and largely vanished as modern humans advanced out of Africa through the Middle East and into central Asia and Europe.