Identification help - shell found in Greece

[bitwise]

I found this shell in about 10 feet of water. Does anyone know what this thing is?

 

[bitwise]

One more photo

 

[C.Eymann]

Urchin shell maybe?

 

[bitwise]

Urchin shell maybe?

It does look like one but the shape is quite different than a typical urchin.

 

[C.Eymann]

Urchins can vary in form, urchins can even be flat (sand dollars) again I'm not 100% sure, but urchin would be my guess, might be a barnacle, but the rough texture makes me doubt it,

 

[C.Eymann]

Did some searching online, it definitely an urchin. Found pics of some that had a somewhat similar pattern and texture. Common name was "sea potato"

 

[bitwise]

Thanks for the help. I think it is a Brissus unicolor.

 

[C.Eymann]

Thanks for the help. I think it is a Brissus unicolor.

No problem

I would agree with you on that ID. looks identical.