Perissopyge (Trilobita) from the lower Cambrian (Series 2, Stage 4) of North America and Greenland

The distinctive trilobite Perissopyge phenax was originally described from the Henson Gletscher Formation (Cambrian Series 2, Stage 4) of central North Greenland and reported from the Sekwi Formation of Yukon Territory, Canada. This latter material is illustrated herein for the first time. Perissopyge phenax is also currently described from the Paralleldal Formation of Peary Land, North Greenland, some 100 km east of the type locality, where overlying strata correlate with the middle-upper Toyonian Stage of Siberia (Cambrian Stage 4). Perissopyge triangulata, from the Harkless Formation (Cambrian Stage 4) of Nevada, is also discussed and tectonic deformation of the type suite is recognized. An indeterminate species of Perissopyge is identified in the Ella Island Formation of North-East Greenland. The Ella Island Formation yields Olenellus hanseni, which is possibly synonymous with O. cf. truemani from the Henson Gletscher Formation. Together, these occurrences enhance stratigraphical correlation between central North Greenland and North-East Greenland and suggest some utility for Perissopyge in correlation of the lower half of the Laurentian Cambrian.