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Determining if the petrogliph was human made or not

Posted by WalterNeves on 23 Mar 2012 at 15:53 GMT

A question has been raised on some blogs and forums of how we determined that the petroglyph described in our paper was human-created. This is easy to answer: 1) it was pecked on the rock surface, and pecking only occurs if someone pounds a rock, not by sediment attrition or any other means; 2) the pecking was regular, following straight lines; 3) the figure is consistent with intentionality: it has a head, a body and limbs. We believe that this question was raised mostly by people that did not read the original paper and, most important, did not see the supplementary material, where "stick man" figures witgh C-shaped heads found in other settings are presented. Therefore, the figure we found is not an isolated find.
A good example of a (serious) blogger that "dismissed" the paper and later found that he was wrong:

Competing interests declared: I am one of the authors