The surprising artifact could be evidence of fertility rituals—or just one of history’s strangest good luck charms.

While excavating outside London, archaeologists discovered thousands of bones thrown down a quarry shaft in Roman times. But one, in particular, stood out: a dog's baculum (penis bone) that had been painted red on one side.

The pits were used to extract chalk and flint during the Roman era in England during the first century A.D. and were later backfilled. One of the pits was filled with both human and animal bones — and now,

A bio-archaeologist with the University of Reading, in the U.K., has found an ancient dog's red-painted penis bone along with a trove of other bones, in an ancient Roman era quarry shaft. In her paper published in the Oxford Journal of Archaeology,