Weird "shell"

[KureckiPL]

Hello!
I've got a problem, would you mind helping me to indentify what animal did this shell (or sth. like shell, I'm not sure ) belong to?

[biohazard]

To me that looks like a spider crab of some sort. However, the biggest species are usually the size of a large plate or something, so maybe that's a baby one. Or one of the smaller species.

http://chestofbooks.com/animals/Manual- ... uinado.jpg

The big ones look like real monsters:

http://www.animalpicturesarchive.com/Ar ... 251110.jpg

(see the kid in the background for size comparision)

[KureckiPL]

Thank you for your help, It's definitely Maja squinado

[ColouredStuff]

There has been a spider crab exhibit in Liverpool Museum for as long as I can remember. Seeing that monster for the first time as a child was a life changing experience. It was the first time I realised that the natural world extended almost infinitely beyond my comprehension, and made me hungry to learn more about it. I think I even mentioned it in my personal statement when applying to uni.