Again, the stones were PAINTED around 1960 they are an art project at best, but people in the ancient aliens circles have been passing them around as artifacts, so they are in that context a hoax.
Yes, some are real, the real ones depict fish and flowers, someone received one of those ancient stone, that did not depict a dinosaur, thought it was cool and replicated them with dinosaurs, planes and other designs basically for a tourist gift shop trinket.
Then someone from the ancient aliens circle, picked it up, held it up as evidence that Inca's had planes, UFO's and rode dinosaurs (which the dinosaur thing is what the young earth creationists picked out from what some of the above writers included).
If the bible includes descriptions of UFOs, people riding dinosaurs, feel free to include that evidence too, although you quickly get into the problem of whether aliens are chosen by God as well or just the Jews.