Not sure where you are in Mississippi, but there's a place near Tuscaloosa on the Pickens Co. Green Co. line, which has become a commercial enterprise because of the fossils in a creek bed on the land. The owner might be able to help you identify some of those -- most of what is on his property are shark teeth, but there are some other examples on display there. I don't know how to post a link but here is the address of the site
http://sharktoothcreek.com/