Beautiful Russian trilobites

Paraceraurus exsull

Coming from the nearly half billion year old Middle Ordovician Asery Level deposits of the Wolchow River region near Saint Petersburg, Russia, this is an example of a member of the Order Phacopida, Family Cheiruridae called Paraceraurus (formerly Cheirurus) exsull. These are very dramatic trilobites, with expansive genal and pygidial spines.

Found at Fossil Mall, via Minerals and Fossils.