If you haven’t found yourself wondering how a Paleolithic man would decorate his penis, well, neither have I. But a group of French and Spanish urologists were apparently curious about that very question.

In a Journal of Urology paper called “Phallic Decoration in Paleolithic Art: Genital Scarification, Piercing and Tattoos,” they review art objects from the Paleolithic period, finding dozens of what they call “phallic pieces.”

Archaeological evidence that has survived to our day includes 42 phallic pieces, of which 30 (71.4%) show intentional marks to a different extent with a probable decorative purpose. Of these ornamental elements 18 (60%) were recovered from the upper Magdalenian period (11,000 to 12,700 years ago) in France and Spain, and 23 (76.7%) belong to the category of perforated batons. Decorations show lines (70% of objects), plaques (26.7%), dots/holes (23.3%) or even human/animal forms (13.3%). These designs most probably represent skin scarification, cutting, piercing and tattooing. Notably there are some technical similarities between the motifs represented and some designs present in symbolic cave wall art. This evidence may show the anthropological origin of current male genital piercing and tattooing.

They conclude:

It is obvious then that deep incisions, concentric lines, protruding surfaces, holes and series of dots in the pieces that we studied faithfully represent precise cutting, scarring, piercing and tattooing on the penile skin and mucosa. These practices could imply group recognition. Similar procedures are known to have been performed by primitive modern humans. Briefly, ritual and/or decorative penile ornamentation is represented in the Paleolithic graphic registry. It could be the anthropological origin of a peculiar habit that has at times reached our days.

I understand that the paper was originally submitted to Prick, a “tattoo, piercing, and lifestyle magazine,” but rejected because the authors didn’t provide enough pictures.