Trilobite fossils have been found on all of today's continents. Trilobites existed in a very large variety of species that lived around 540 to 290 million years ago (Cambrian-Perm). The entire trilobite group died out at the end of Perm at a very large mass extinction. Trilobites had exoskellet, as well as current arthropods (surface mounted skeleton). The name trilobite translates as three parts / lobes that the body is divided into three segments.