I have many relatives who live in Florida and I know for a fact that Florida has very few if any true rocks throughout most of Florida, with the exception of maybe the panhandle....BUT what the state does have is lots of ancient coral and agatized coral, the state rock/stone is agatized coral, in most states if you dig deep enough you will eventaully hit bedrock, not so in Florida..but if you dig deep enough you will hit coral most everywhere, the majority of the state sit on this ancient coral and it is used or once was as building materials just as rock and stone is many other places.
I think this is what you have, a BIG chunk of coral, as far as the "bones", I guess that when the coral was alive and growing it could have grown over and or on a dead animal skeleton of some type.
No it was not exposed! My stepdad dug it up out of the ground just in front of where it is placed now! That is only half of it! The other half broke off and he said it was just beat back down into the ground probably 100 ft north of where it is! I stated previously that it was dug up in 2002, but I was wrong! It was actually 1998 when we purchased the property!! & Thank you for your insight!!! 😁
Myke Steighler found the strewn field and probably owns most of the mass, he's on CSR but I don't know if he is here. I've been out there once, the hunting is very difficult and finds are few and far between.