Thank you everyone for playing our National Fossil Day game! The fossil is in fact a hyperostosis from a fish (sometimes called a tilly bone as @william-howat aptly suggested). @jnance suggested it’s from a spadefish (Ephippidae).
@aaron-wood you fell into the trap. When I first found this I thought I had found a dugong tooth and was very excited, but under greater inspection realized it was a tilly bone. It has a texture very characteristic of fish bone. However, don’t feel bad because I showed this to a lot of people here are UF and about half thought it was either Metataxytherium or a peccary tooth at first.