Ok to make stone cut engravings like we see above you would require a diamond chisel and hammer stone, we can see no reason to suppose widely disparate "Paleolithic" peoples, would each have the same tools and possess the same artistic acumen and patience to get it done.
Only leaves space travellers, maybe they left self portraits as in the "spaceman" type figures that appear on the carving tableaux, like the ones above from Sego Canyon Utah.
We have a problem with the "cave art" as well, and say the sweeping lines on the bison and leonine depictions from Chauvet Cave more particularly show a schooled hand.
boekanier 0 points 2.2 years ago
some researchers do have a very vivid imagination.