Balizoma and the new genera Aegrotocatellus and Perirehaedulus: encrinurid trilobites from the Douro Formation (Silurian, Ludlow) of the central Canadian Arctic

Abstract

Species of two genera of Encrinuridae occur in the Ludlow Douro Formation at Goodsir Creek, Cornwallis Island, Garnier Bay, Somerset Island, and Prince Alfred Bay, Devon Island. The encrinurine Aegrotocatellus n. gen. includes four highly autapomorphic species, and is most closely related to Balizoma Holloway, 1980. Perirehaedulus n. gen. is a coronocephaline most closely related to the Chinese upper Llandovery taxon Kailia Chang, 1974. The upper Wenlock-Ludlow range of Balizoma is extended into the Arctic by Balizoma aff. B. variolaris (Brongniart, 1822) from Homerian rocks of the Cape Phillips Formation near Abbot River, Cornwallis Island, and by Balizoma sp., from the late Ludlow Douro Formation at Goodsir Creek. -from Authors