This is a very large 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 part of the hypostoma (mouthplate) is displayed in the center of the head. The trilobite is quite inflated and 3-D for this locality. The bug has very nice color and contrasts very well with the lighter-colored matrix. The trilobite is almost perfectly centered on the rectangular block of limestone. This is a collectible example of a very large Isotelus mafritzi from Ontario, found well over a decade ago.