This is a very aesthetic specimen of Isotelus mafritzi from the Ordovician of Canada. This outstretched trilobite is wonderfully articulated and exhibits fine detail. The small, crescent-shaped eyes are easily seen, and the short genal spines are quite evident. The trilobite is nicely inflated, and the thick-shelled exoskeleton is beautifully preserved. The bug has outstanding color and contrasts well with the lighter-colored matrix. The fossil is almost perfectly centered on the rectangular plate of limestone. This is a very attractive example of Isotelus mafritzi from Ontario.