What is "hexaplex"

Hexaplex is a genus of medium-sized to large sea snails, marine gastropod mollusks in the family Muricidae, the murex shells or rock snails.

This genus is known in the fossil record from the Paleocene to the Quaternary period (age range: from 61.7 to 0.012 million years ago.). Fossil shells within this genus have been found all over the world.