Trilobites were in the extinct class Trilobita. Trilobites are probably the first fossils collected by man. In one case a trilobite with a hole drilled into it was found in the remains of a 15,000 year old settlement.

Next to dinosaurs, trilobites are the most well known fossil group and are the largest group that is entirely extinct.

There were 10 orders of trilobites , over 180 families, about 5000 genera and 15,000+ described species!


Though extinct since the permian, Trilobites were hardly a "flash in the pan", in fact, they were around nearly 300 million years, much longer than the dinosaurs.

This particular specimen, Calymene tristani, is from the order Phacopida, family Calymenidae.

The seller, Stones & Bones, lists it as being from the Silurian, but most authorities say this species is from the mid ordovician. This specimen is quite a bit larger than the Elrathia kingii found in the growth series, and comes from Morocco rather than Utah.

It is typical in Morocco to split a promissing rock open to see what's inside. This often splits the specimen so that a lot of repair is needed.

Sometimes, however, it is left in this state and sold as is. The result could hardly be described as expertly prepared but, as clearly shown by the pictures on this page, it has a lot of potential for stereoscopic imaging!