Marcus, I have found fossils with calcareous opercula still in place. Allen Aigen [log in to unmask] -- Marcus Coltro <[log in to unmask]> wrote: Have you ever found a long time dead, incrusted shell with operculum on its place? I was snorkeling years ago in Samoa and found this ugly Turbo buried under a rock http://www.wonderphotos.com/shellphotos/turbo.jpg The aperture is completely sealed so I imagine it took a lot of time to bacteria consume the animal! Marcus -- No virus found in this outgoing message. Checked by AVG Free Edition. Version: 7.1.409 / Virus Database: 268.14.10/541 - Release Date: 20/11/2006 ---------------------------------------------------------------------- [log in to unmask] - a forum for informal discussions on molluscs To leave this list, click on the following web link: http://listserv.uga.edu/cgi-bin/wa?SUBED1=conch-l&A=1 Type your email address and name in the appropriate box and click leave the list. ----------------------------------------------------------------------