Help with identification please

[thrubwell]

I found this "shell" on  a beach in northern Sardinia.

<a href="http://www.badongo.com/pic/6995896" target="_blank"><!-- m --><a class="postlink" href="http://www.badongo.com/pic/6995896">http://www.badongo.com/pic/6995896</a><!-- m --></a>

It's not like a normal shell. It's very light and brittle.

Thanks in advance for any help.

Al

[paul monfils]

Hello Al,

You are right.  It is not like a normal shell, in fact technically it is not a shell but an egg case.  This is from an argonaut, scientific name Argonauta argo.  The animal that made it is not a snail, but a cephalopod, a close relative of squid and octopus.  The female constructs this structure to lay her eggs in, and once the eggs have hatched, she just releases it and it floats away until it gets deposited on a beach somewhere.  As you might imagine, these are not commonly found in good condition because they are so fragile.  

<a href="http://en.wikipedia.org/wiki/Greater_argonaut" target="_blank"><!-- m --><a class="postlink" href="http://en.wikipedia.org/wiki/Greater_argonaut">http://en.wikipedia.org/wiki/Greater_argonaut</a><!-- m --></a>

.  <span class="petit">--Last edited by Paul Monfils on 2009-08-28 03:15:21 --</span>

[thrubwell]

Many thanks, Paul, for your reply; now I can do some research.

Al