I have never read why, but when you look at a cowry with expanded mantle,
and considering the animal is going completely (at least in the species I
observed), then one may think the teeth guide the mantle and the animal to
withdraw perfectly in this tiny hole. Probably there are cells in the mantle
that detect the correct teeth, so very quickly it can withdraw in the
correct way, better than if there were no teeth.
Note: Ovulids most often do not have the teeth, but frankly I think Ovulids
do not withdraw the animal often. But also most Trivia and Erato have them.
Other ideas ?

Guido

‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹
Visit Conchology, with over 50000 names with author, 3800 indicated type
species, 5000 conchological images, and fun with shells.

http://www.conchology.uunethost.be/
‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹‹

> From: Nancy Smith <[log in to unmask]>
> Reply-To: Conchologists of America List <[log in to unmask]>
> Date: Wed, 24 May 2000 16:53:34 -0400
> To: [log in to unmask]
> Subject: bones, teeth, humans and molluscs
>
> Okay, with all of this talk about shells with bone names, I'm finally willing
> to show my stupidity and ask a question which has been in my mind for some
> time.
>
> Why do cowries have teeth?  (absolutely NO responses that contain "better to
> eat you with", either!)
>
> Preparing for the barrage of laughter,
> Nancy
>