This is a HUGE specimen of Isotelus mafritzi from the Ordovician of Canada. This outstretched trilobite is wonderfully articulated and exhibits fine detail. The large tail is easily seen, and the short genal spines are quite evident. The extremely large (almost five inches long!) trilobite is nicely inflated, and the thick-shelled exoskeleton is well preserved. The bug has nice natural color and contrasts well with the lighter-colored matrix. The fossil is well presented on the large plate of limestone that contains many other fossils. This is a massive example of Isotelus mafritzi from Ontario.