 Fossilization is a unique event. It has to be catastrophic, it has to be quick, and we only see that in a flood dynamic. Fossils don't just form in flood conditions. They form when they're separated from things that are scavenging. Fossils that are buried in things like big dinosaur graveyards. The reason why we know that these are seasonal flooding events rather than a massive global flood is because some of these bones cross strata. The bone at the bottom half is completely pristine. The top half of the bone has nibbling, roots grow into it, all sorts of stuff like that. People have a misconception that when God flooded the earth, it just filled up like a bathtub all of a sudden. That's not the way it occurred.