This is a very large trilobite. It is an adult Trimerus delphinocephalus from Middleport, New York. This is one of the more uncommon types of trilobites from the Rochester Shale. This specimen is complete and is a full seven inches long - very few types of trilobites found in the United States are this large. The specimen has nice coloration and good detail. The thick shell exoskeleton is well-preserved. The bug is nicely centered on the matrix block, not on the edge of the plate. It is also very inflated and 3-D for this type. This is a fine, large example of this species.