Kurt Auffenberg wrote concerning Bynes' disease,
"...And watch your cowries, some muricids, small cones, and micros in
general.

Now, that is interesting. In the Cretaceous and Tertiary shell deposits of
Alabama, some groups of aragonitic shells weather more rapidly than others,
even right next to one another in the sand or silt. Almost all gastropods
weather more quickly than almost all bivalves, regardless of shell
thickness. Some gastropods weather especially quickly, notably the cones
and epitoniids. I surmised that this was due to shell structure--the size,
orientation, and packing of aragonite crystals in layers within the shell.
Organic matter may also be part of the shell, and some may remain after
tens of millions of years; bivalve ligament is commonly preserved in the
Eocene beds. But it's interesting that some of the same families of
gastropods deteriorate relatively quickly whether they are modern or
fossil. I would like to hear more about this.

Thanks for all the comments on Bynes, people! This has been an informative
conversation.

Andrew K. Rindsberg
Geological Survey of Alabama