This fossil Ceraurus pleurexanthemus is a RARE trilobite species that was collected a very long time ago from the world famous Ordovician type site of the Trenton Formation in Trenton, New York from which the formation was named after. Specimens like this are very difficult to obtain now and must come from old collections as this one did. Trilobite is in nice preservation with a portion of the left pygidial and genal spines missing but otherwise complete. This was the ONLY specimen of this type from a large and very old estate collection. For a diverse North American trilobite collection, we highly recommend this piece as it is a scarce opportunity for such an acquisition.