Full reference: H. B. Whittington. 1963. Middle Ordovician trilobites from Lower Head, western Newfoundland. Bulletin of the Museum of Comparative Zoology 129(1):1-118
Sister taxon: Glaphurus pustulatus
Type specimen: GSC 16183, a cephalon/head. Its type locality is Alpha Boulder, Table Head, which is in a Whiterockian reef, buildup or bioherm limestone in Canada.