Kinda reminds me of OOPAS (out of place artifacts) like this:
Serbian archaeologists discovered a series of iron nails in a layer of sand during excavations in a coal quarry, and also found mammoth bones in the same quarry. Both discoveries were made at a depth of 23ft. After a quick study, experts concluded that the boats date back to the Roman period, and the bones are estimated to be millions of years old.
