12,000-year-old rock art hints at the Arabian Desert’s lush past

The camels at Jebel Misma have been frozen in a march for 12,000 years. “They are really spectacular,” says paleoanthropologist Michael Petraglia. “They’re beautiful, monumental.”  

A herd of the animals are cut into a cliff towering above the mostly flat desert landscape of Saudi Arabia’s Nefud. The engravings are life-size, inscribed with about 150 other newly documented petroglyphs that all date to between 12,800 and 11,400 years ago, Petraglia and colleagues report September 30 in Nature Communications.

Rock art has been found in Saudi Arabia before, but those petroglyphs date from the Neolithic period around 8,000 years ago. The engravings found at Jebel Misma, Jebel Arnaan and Jebel Mleiha — all rock outcrops in a remote part of the Nefud, near its southern edge — are much older. The engravings can be seen for miles and were probably intended to mark territory or indicate nearby sources of water, says Petraglia, the director of the Australian Research Center for Human Evolution at Griffith University in Brisbane.

The newly discovered rock art was found during research for one of Petraglia’s projects, called Green Arabia. The team recently published evidence that the region was lush and verdant at times over the last 8 million years, indicating that the Sahara and eastern desert regions were also wet.

Petraglia and his colleagues think the earliest rock engravings at Jebel Misma and the two other outcrops nearby were made by the first nomadic people to enter the region after the Last Glacial Maximum, which made the region arid but ended about 19,000 years ago. As the region became wetter, with more rain accumulating in temporary desert lakes or “playas,” wild animals such as camels, gazelles, aurochs and ibex arrived — followed by nomadic human hunters who relied on them for food.

The hunters’ engravings were cut into the natural dark “varnish” that forms on desert rocks, to expose the sandstone beneath. Analysis shows they were made in four phases: The earliest, carved more than 12,000 years ago, depicted small, stylized women, often with accentuated curves, and were later covered by other engravings. A second phase of petroglyphs depicted larger stylized human figures.

The stunning animal engravings — naturalistic in style and up to 3 meters long — date from a longer third phase that ended about 11,000 years ago. Each animal is depicted with distinctive individual features. A fourth phase consists of “cartoonish” animal depictions that are more stylized and represent the evolution of the tradition, the study authors write. They note that the last lush era ended in Arabia about 6,000 years ago, once again turning the Nefud into one of the driest places on Earth.

Excavations of trenches beside the engravings unearthed stone tools and other objects that reveal the artists had close links to other prehistoric peoples in the Eastern Mediterranean. But the size and style of the engravings set them apart and show the origins of a new tradition. The nomads were “creating this monumental rock art, which we never saw before,” Petraglia says. “This is a brand new phenomenon.”

Paleoclimatologist Paul Wilson of the University of Southampton in England says the research by Petraglia and his colleagues shows how prehistoric humans adapted to changes in climate. “Just like its African counterpart [the Sahara], the Arabian desert is graced by countless prehistoric engravings and paintings that provide … incontrovertible evidence of occupation by our ancient ancestors,” he says.

Archaeologist Anna Belfer-Cohen, a professor emerita at the Hebrew University of Jerusalem who studies the prehistory of the region, says it might be expected that prehistoric people in Arabia were experimenting with new ways of living. The work by Petraglia and his colleagues opens a new window into a past time. “It tells the story of a region that was for years terra incognita, so much so that people did not even consider exploring it,” she says. “These findings are eye-openers.”