Or could they have been blown ashore in that condition?  Maybe an
offshore community that gets deposited when dead on a
reef/sandbar/whatever.  There to get beat up, dissolved, chipped, etc.
until the big storm carries them the rest of the way ashore.  Who knows?

Tom Eichhorst in New Mexico, USA

[log in to unmask] wrote:
>
> Recently, we discussed the fact that some shells dissolve more readily than
> others. Here is an example of a shell that looks robust, but is actually
> rather brittle. The Eocene Gosport Sand of Alabama (USA) includes shell
> beds deposited in storms. Gastropods typically have chipped or broken lips,
> and are commonly filled with shells that look as though they were jammed
> into the aperture. An unidentified species of Busycon is fairly common in
> the Gosport Sand at Little Stave Creek, but is only rarely found complete.
> Most specimens consist only of columellas or of equant chunks that may
> include one of the distinctive low spines. The species is one of the
> largest in the formation, and the shell looks robust. Other large, common
> gastropods are relatively well preserved. My question to you is: Are modern
> Busycon shells more brittle than those of other large gastropods?
>
> Andrew K. Rindsberg
> Geological Survey of Alabama