Keywords: Ampyx nasutus, Middle Ordovician, Lynna Formation, St. Petersburg region, Russia - Houston Museum of Natural Science - DSC01432.JPG An Ampyx nasutus trilobite Order Asaphida Family Raphiophoridae collected from the Lynna Formation St Petersburg region Russian Republic from the Middle Ordovician Specimen on display at the Houston Museum of Natural Science collection number DSC01432 Photography was permitted in the museum without restriction Daderot 2012-10-22 14 01 24 Daderot cc0 cc0 Trilobites in the Houston Museum of Natural Science Ampyx nasutus |