Trilobites were prehistoric bottom dwelling marine creatures. They are related to the modern day horse shoe crab. They had a hard exoskeleton body which was conspicuously segmented which enabled them to roll up just as a modern roly- poly. Crotalocephalus is a genus of trilobite that lived from the Late Silurian to the Early Devonian. Its remains have been found in Asia, Australia, Africa, and Europe.This is a unique, one of a kind, fossil. Once this item is sold, we will not be about to acquire an exact replacement. All Paxton Gate specimens are guaranteed to be of the highest quality; sourced from ethical vendors and private collectors around the world.