What is this? Notched and flat, found in the shallow waves in Satellite Beach, FL

[lisac29]

Hi, I'm new here, looking those with expertise to help identify this, appreciate any help.  I found this in the water, about 2 or 3 feet from shore.  I think it might be a part of a turtle shell, but it also looks like a sacrum.  Any ideas?  It's rather heavy for it's appearance. 

[Crusty_Crab]

Piece of sand dollar perhaps.

[Sjfriend]

I'm not sure but I know turtle/tortoise shells have notches like that on rear

[Lone Hunter]

Yes they do, got my turtle to pose.  But that looks too thick I think.

[Rockwood]

We really need a closer look at the texture, but I'm leaning turtle on this one. I think it's more like bone.

[Rockwood]

3 minutes ago, Lone Hunter said:

got my turtle to pose. 

This turtle isn't leaning. It's flipped ! 

[jpc]

I agree wth turtle... from the back end of the carapace, not the plastron.   I don't know enough about FL modern and fossil turtles, but the notch may be distinctive to a certain type of turtle.  

[lisac29]

Here's two more pics, trying to get more texture.  There's an indented line down the top center.  

[Lone Hunter]

Didn't have to flip this one, forgot to add that tortoises and some turtles have the notch on front of plastron where it's thicker, notch can be on front of carapace also(last pic).  I can't recall seeing a notch on the rear of a turtle carapace.

[Lone Hunter]

And wouldn't the line be more consistent with the plastron?

[Sjfriend]

With new photos,, definitely turtle/tortoise shell. With how narrow the notch is I'd surmise rear plastron. Can't help.more then that.

[Rockwood]

Yep, turtle of some type.

[Rockwood]

47 minutes ago, Lone Hunter said:

And wouldn't the line be more consistent with the plastron?

I'm afraid you are oversimplifying the situation. The external sheath of one species is insufficient as a sample.  

[Al Dente]

Most likely a pygal plate from a sea turtle.

 

 

[Rockwood]

I see.