Paraceraurus exsul
Paraceraurus exsul is a species of trilobite that lived in St. Petersburg Region and Tver Region of Russia, Estonia, Finland, Sweden, North Germany, Lithuania and Belarus during the Upper Llanvirnian Stage of the Middle Ordovician. These trilobites can reach a length of about. They show a square front edge, large genal spines on the cheeks and characteristic long pygidial spines. Genal spines are curved usually inward and upward.