A Jiangshanian (Cambrian; Furongian) trilobite fauna from the Cow Head Group, western Newfoundland

Abstract

Three shelf-derived boulders in debris flow conglomerates of the Downes Point Member of the Shallow Bay Formation of western Newfoundland yielded the first record of an Upper Cambrian shelf-margin trilobite fauna from the Elvinia Zone (Steptoean; Jiangshanian) in eastern North America. The fauna is dominated by the “catillicephalid” Buttsia Wilson, 1951, and resembles trilobite biofacies from microbial buildups in the Gatesburg Formation of Pennsylvania. It is correlative with the Cliffia latagenae Subzone, which is the youngest Steptoean biostratigraphic unit in the Gatesburg. New taxa are Triorygma burkhalteri gen. et sp. nov. and Buttsia trema sp. nov.