Here is a fabulous specimen of an unusual trilobite. This is a HUGE Illaenus atavus from the Lower Ordovician of Russia. This species of Illaenus has a very long, almost smooth pygidium and rounded genal areas. This extremely large trilobite (a full four inches long!) is extremely inflated and very well preserved in an outstretched position. The small, wide-set eyes are easily seen, and the individual thoracic segments are quite distinct. There is also a complete Asaphus and a partial trilobite on the plate. The butterscotch-colored bugs contrast beautifully with the light-colored matrix. The fossils are well showcased on the large, sculpted plate of limestone. This is the largest, best example of Illaenus atavus that we have ever seen.