I conclude that one must look at all evidence with an open mind. Myths may indeed be myths. On the other hand, myths may be based upon actual events. Pictographs may be works of imaginative art. On the other hand, they may be representations of living creatures, actually seen and hunted by the artist.
“There are more things in heaven and earth, Horatio,
Than are dreamt of in your philosophy.”
Open mind.
Or they may be something in between - an imaginative artists rendering based on observed fossil remains.
We can find the fossilized remains of Stegosaurus. If they lived with, and were hunted by men, where are the fossilized remains of those men?