I only skimmed the article, but I just wanted to point out that the provided HN title differs significantly from the actual paper title, in a way that is potent

I only skimmed the article, but I just wanted to point out that the provided HN title differs significantly from the actual paper title, in a way that is potentially misleading. The stone tools use in question is not the flintknapping that we usually think of. It is, in essence, just picking up a rock and using it as a hammer to bash things. Nor is this paper purported to reset the timeline on early human anthropology. The archaeological sites in question are a specific set of sites in Brazil where evidence of that kind of tool use had been interpreted by some to be evidence of early human presence in the Americas. As the article itself points out, though, that has been a subject of debate for decades. The earliest citation for the monkey hypothesis for the origin of these sites that I noticed the article mentioning is from 25 years ago.