Spotting

It's a part of a Squilla Mantis, it's commonly eaten in that region. It's known as "Canocchia".

Thanks for this Information!!!!!!!

That's a caudal plate from a mantis shrimp...it covers the tail

Yes, my wife found it and we have no idea what it can be. I´m a diver, but i never seen something like this before. It´s not a part of a fish, it was really hard, like a part af a crab.

Wow interesante