Diversity of Triplicatella and Related Hyoliths in Cambrian Series 2 of Greenland (Laurentia)

Isolated opercula from the lower Cambrian (Series 2) of present-day high arctic Greenland represent a group of triplicatellid orthothecids (Class Hyolitha) that originally inhabited equatorial seas offshore from eastern Laurentia. With five species from the Aftenstjernes & oslash; Formation and one from the underlying Buen Formation, they comprise the most diverse known assemblage of Triplicatella, a genus originally established in South Australia but recognized subsequently from China, Laurentia and Siberia. A seventh species also from the Aftenstjernes & oslash; Formation is assigned to a new triplicatellid genus, Biplicatella, with type species Linevitus opimus from the Chengjiang biota of China. New species: Triplicatella paluaq, Biplicatella skovstedi from the Aftenstjernes & oslash; Formation of North Greenland. http://zoobank.org/urn:lsid:zoobank.org:pub:3280A2C8-5481-4106-8B39-78CDE3E0BC36John S. Peel* [john.peel@pal.uu.se], Department of Earth Sciences (Palaeobiology), Uppsala University, Villav & auml;gen 16, Uppsala SE-75236, Sweden.