An article by Sarah Wells on inverse.com - Old Drugs Found in California Cave Rewrite Native History - reports on research into the connection between drug use and human creativity which has not been revealed in the archaeological record.

Scientists now believe that the pinwheel rock drawing (left) represents the flower itself instead of the shaman's trance experience. Image: Devlin Gandy. Like the rock painting, the Datura flower (centre) spirals out in a pinwheel-like shape. Image: Melissa Debulamanzi. An on site size comparison (right) of the quid fibers to the pinwheel painting. Image: David Robinson

Researchers had evidence early native Californians used certain wild flora to enter trance states, but exactly how and why these early Californians got high has been subject to fierce debate in the archeological community for decades. Now, a team of scientists may have found an answer in rock art sites.

For decades, archaeologists believed early Californians' rock paintings depicted three unique visual phases of a hallucinogenic trance — in this case, the personal trance experience of a community shaman — to the exclusion of the rest of the community. But until now, researchers had no clear evidence of hallucinogen remains at these supposed trance sites.

Using sophisticated technology to study the fibrous remains of these hallucinogenic flowers on a microscopic level, the researchers discovered an unusual connection between the flowers and the paintings they were found near. The finding could overturn the prevailing consensus on how and why these hallucinogens were used.

Study co-author David W. Robinson, a lecturer in archaeology at the University of Central Lancashire, explains that " tells us a lot about how integrated rock art and ritual into their daily lives." Published recently in the journal Proceedings of the National Academy of Sciences, the researchers analyzed clumps of plant fiber they found wedged in the ceiling of a rock painting site called the Pinwheel Cave, in California's San Emigdio Mountains.

On the cave's ceiling is a painting which depicts a rotating spiral unraveling from a circular point at its center. It was thought the spiral represented a shaman's individual experience, but the new analysis suggests it is actually a drawing of a hallucinogenic flower native to the area — Datura — whose image it closely mirrors. This area has historically been, and is still considered to be, part of Chumash territory and is now represented by the Tejon Indian Tribe.

The team first used 3D digital microscopy to evaluate the fibers. In particular, they looked for evidence of bite marks — tell-tale hints these fiber bundles, called quids, were once chewed and then stuck into the ceiling afterward. As suspected, the researchers did find tell-tale bite marks in most of the quid bundles. Some of the bundles dated to the year 1523 — pre-colonization.

The researchers then did a chemical analysis to look for hallucinogenic components known to be found in Datura, including scopolamine and atropine. Finally, to complete the emerging puzzle, the team used a scanning electron microscope to zoom in and create a micrometer image of the plant fibers found in the cave to make the final determination that they were indeed from the Datura plant. The authors speculate that each individual quid was likely a single dose of the hallucinogen.

The discovery is the first example of hallucinogens being discovered at the site of a rock painting. But according to Robinson it also changes the story archaeologists had been telling about these native peoples. " tells us a lot about how integrated rock art and ritual into their daily lives. People were doing this literally right under the paintings. Even if the actual consumption of the Datura took place at different times than when people were using the cave ordinarily, the art was a constant reminder of the importance of the plant and its central role in society."

Robinson and his colleagues also found remnants which suggest the cave was used widely — there's evidence of hunting, gathering, cooking, eating, and potentially storage taking place in the Pinwheel Cave. " evidence at Pinwheel Cave shows that the hallucinogens were taken in a group context, and that the art communicated the ecology of the plant behind the trance rather than the images seen during the trance. Rather than being private retreats of male shamans to the exclusion of everyone else, the rock art site as a deeply meaningful place of inclusivity for the entire community.

Click here to visit the American Rock Art Archive