Usually I don’t go deep regarding a turtle shell fragment but this is different than most I have found.
Found in the Peace River Formation, Bone Valley Member.
Reading The Fossil Vertebrates of Florida (Hulbert, Jr., 2001) the author mentions that “there are only two genera of thick shelled tortoises in the US (Oligocene to Pleistocene) which are Hesperotestudo and Caudochelys”.
The shell fragment bellow is robust, and weirdly thick compared to the other many fragments I have found in the Peace. Help?
I honestly do not know how to ID these, so you might want to disregard my response, but it kind of resembles Cheloniidae to me. Of course, it could also just be a very thick piece of Hesperotestudo plastron…