Here is a nice specimen of an unusual trilobite. This is Illaenus atavus from the Lower Ordovician of Russia. This species of Illaenus has a very long, almost smooth pygidium and rounded genal areas. This detailed trilobite 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. The butterscotch-colored bug contrasts beautifully with the light-colored matrix. The fossil is well presented on the sculpted plate of limestone. This is a very attractive example of this uncommon species of Illaenus.