This is just a guess, but my thinking is that after the meat was dried, it would have been chopped up with a small chopper like the one shown. Then, the chopped up meat was ground down finer with the mano/metate, and mixed together with dried local fruits to make pemican.
Because it's not a specific tool or "style". It could have been a piece in the midst of thinning, things weren't going right so they discarded it. It could have been a rudimentary expedient tool needed for a quickie task. It's not a readily recognized form - it's a biface.
Its a Oval Scraper. They date late Paleo and Early Archaic. Your has the patina of the older style. It is very nice and can I have it? I love scrapers.
Ah Duval. They don't all have that bulbous base that fools people over type, but almost all have the diamond cross section, a diagnostic trait boom! LOL
Your piece I would call a small scraper, like a thumbnail only bifacial, looks ground on top no doubt used in hand, even the "base" could have been used and looks ground/worn. Sweet tool. Yes, patina looks old to me, too. Nice color don't think it was heat treated> I've seen similar colored chert in Hillsborough Co.
FL Greenbriar, rice-grain chert, filthy ground base and notches, reported to the IFP I have a paper says I own it.
I think the secondary work on the edge is the clue to the tool. As far as dating it unless it is found in context they were made by every culture. Because another type is beside it on the ground means nothing. But if it was dug out of the ground it means everything. I am not a scientist and can not date by patina alone. And being oval does not make it paleo or archaic. The title here was what would you call it? Biface tool with secondary edge work. Nice tool at that
GB, that IS a schweeeeet example of Bulbous Base Duval. Classic all the way So many of that type are funky. I have only one, maybe two out of a bunch that are as well done and classic boom.