The signs painted in caves have been preserved to this day but at the time I guess that they were also used outside, on rocks and on trees, and that they were l

The signs painted in caves have been preserved to this day but at the time I guess that they were also used outside, on rocks and on trees, and that they were lost to time... With perhaps the exception of dance, the classic arts really are prehistoric mnemonic/communication devices which were made obsolete when writing was invented. They were so useful though that craving them has been carved in our genes, and we still like a good story/song to this day.