(CNN) -- Archaeologists in Russia have discovered an "extraordinary" group of Stone Age artworks which appear to have been carefully buried in pits and covered with mammoth bones, researchers announced this week in a paper published in the academic journal, Antiquity.

Archaeologists uncovered this Stone Age figure -- seen here from four angles -- buried in pits in Russia.

At least some of the 21,000-22,000-year-old objects appear to have been regarded as magical, the scientists surmise.

The collection includes the only example of engravings of images found to date at the site -- what appear to be three overlapping mammoths only a few centimeters long and carved onto the rib of a mammoth.

"The main lines of the image are clear, not ragged; they were made by confident, unbroken movements," Hizri Amirkhanov and Sergey Lev write.

The carving may have been part of a hunting ritual, Amirkhanov and Lev told CNN.

The objects they describe in their new paper "show an extraordinary repertoire of incised carving on mammoth ivory plaques and carving in the round, including representations of women and large mammals, and geometric decoration on bone utensils," they write.

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They also uncovered two female figures, including one 16.6 centimeters tall with a head they call particularly accurate in shape. The figures, which Amirkhanov and Lev called Venus statuettes, had been carefully placed in pits and surrounded with colored sand, Amirkhanov and Lev said.

The archaeologists uncovered the objects in 2005 at a site called Zaraysk, which was discovered in 1980. The site is about 100 miles southeast of Moscow.

Researchers have been excavating the site since 1995, and have found a necklace made of teeth of the arctic fox and a carving of a bison made from mammoth ivory.

Zaraysk is the northernmost known location for a style of Stone Age artwork called Kostenski-Avdeevo after two other Russian locations where art of that type has been found.

Amirkhanov and Lev said the Zaraysk site was on a par with Kostenski and Avdeevo "in terms of the splendor and variety of its art."

The site dates from the Upper Paleolithic period, which began about 40,000 years ago and lasted until roughly 10,000 years ago.

Amirkhanov and Lev's article, "New Finds of Art Objects from the Upper Palaeolithic Site of Zaraysk, Russia," is to be published in the December issue of the magazine Antiquities, a York, England-based journal that describes itself as a quarterly review of world archaeology. A version of their article appeared on the journal's website on Monday; the print version is due out soon, reviews editor Madeleine Hummler said.

The researchers are associated with the Institute of Archeology of the Russian Academy of Sciences.

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