Well now, I was going through some of my Dad's indian artifact notes from seventy years back . He had found a big Caddoan blade with serrated edges and he had shown to an Archeological Anthropologist from the University of Texas. The expert had told him that it was a Ceremonial Caddo Culture spearhead.
Dad always said he thought it was a fish scaler since the Caddos probably spent more time fishing that they did praying.

Hi Red Man, I always wanted to visit a Caddo site, but never made it to one. In thinking about what your Dad said, I think he was probably right, as back then what better tool would there have been for de-scaling fish but a big uniformly serrated knife? And, most of these knives were very high quality, and finely worked. They are highly sought after and very valuable. Like Corner Tangs, they are highly reproduced by modern flint knappers down to the serrated edgework.