Three different people have posted what I think is a very similar if not the same fossil. In my original post I said it was Mississippian. However, I did purchase it from a dealer that described where he found it. I was not there. He was elderly at the time so there could have been confusion. I think he has passed now, so no way to know
Let's assume age is unknown.
Here are the other postings.
https://photos.app.goo.gl/BCMTpriMfuSoaCi79