Hexaplex trunculus (also known as Murex trunculus, Phyllonotus trunculus, or the banded dye-murex) is a medium-sized species of sea snail, a marine gastropod mollusk in the family Muricidae, the murex shells or rock snails. This species is known in the fossil record from the Pliocene to the Quaternary period (age range: from 3.6 to 0.012 million years ago). Fossil shells within this genus have been found in Morocco, Italy, and Spain.