Found in the Peace River, FL. I find a lot of dugong rib bone fragments in the river, most of which are small pieces and have been river polished. I find very few that are of this length. 8+". This one is different enough to me to post for identification. What stands out to me are the rings. There is also very little porous material showing at one end only, and partially down one side. The entire piece, including the marrow looking end, is smooth to the touch from its life in the shifting r