Terence McKenna, thou shouldst be living at this hour:
It has long been suspected that humans have an ancient history of drug use, but there has been a lack of proof to support the theory.
Now, however, researchers have found equipment used to prepare hallucinogenic drugs for sniffing, and dated them back to prehistoric South American tribes….
Scientists believe that the drug being used was cohoba, a hallucinogen made from the beans of a mimosa species.
Caveat: The researchers' abstract dates the paraphernalia to between 400 and 189 BC, which may well be prehistoric as far as those tribes are concerned but isn't exactly paleolithic.