Good question;-
I believe the name (Conch) pronounced: Konk) dates back to the very
early Pliestocene. It eas used as a club of war and held loosely in the
right hand which enclosed the siphonal canal. Th name comes from the
sound it made while coming in contact with the head of an enemy. One can
well imagine a cave person saying, "I gone konk Thang on he punkin
haid."
Happy to be of help.
Anon