Looks like a really nice, intact maybe, Otodus angustidens. Older than megalodon. Almost as big. 33 to 22 million years ago. The rock it is in, is dried mud/clay/organics, and soaking it forever in a bucket of water, rubbing off what you can each day, will eventually free it from the mud. Don't use detergents. After the tooth is out of it's bath, and you show it off, wrap it loosely in several layers of newspaper, or paper towel, and lay it on top of your dresser for a few months. It should come out intact. The enamel sometimes separates from the tooth, if dried to quickly, or cleaned too vigorously. Especially on larger teeth like yours. An exciting tooth. Nice!