I am trying to ID this for my kid

[Curious1]

Hello,

First I would like to say thank you for providing a place for me to attempt to get an answer. I know your time is valuable, so I appreciate anyone who takes a moment to look. 
 

I live in South West, Florida and my daughter and I were at a flea market when she found and purchased this fossil. At first glance I thought it might be an aligator scute, but after looking more closely I know it is not.
 

I doubt that I know enough to even be called a novice, but I spent a few hours online last night trying to find anything that it resembles. Even looking for larger examples that looked like something that this could have been broken off of. I couldn’t find any other type of scute or fossil that it matches. 
 

The person she bought it from said it was found in Florida. (Along with one other that she purchased at the same time that I was able to identify as a deer astragalus.) unfortunately, that is all the information that I have. 

 

Any help at all would be greatly appreciated. 

[Tidgy's Dad]

Very nice marcassite nodule,I think. 

[Curious1]

Wow Tidgy’s Dad! I never would have thought of that. Thank you for giving me a direction to go in on my search

[Al Dente]

It’s a dermal denticle from a large stingray. Here is a link to a similar one-

 

http://www.thefossilforum.com/index.php?/topic/121811-green-mill-run-nc-identity/

[Tidgy's Dad]

Glad to be wrong on this occasion. 

Sorry about that Curious1, it's a nice find. 

[Curious1]

Hi there Al Dente, I do believe you’ve ID’d it. Thank you very much for the help! 

And Tidgy’s Dad, no need to be sorry. I appreciate your input as well. You prompted me to learn about marcasite nodules. :-)