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.
You'll reciever a high quality specimen but not the exact ones pictured here.