Article: Wenlock trilobites and brachiopods from the Mackenzie Mountains, north-western Canada
D. G. Perry and B. D. E. Chatterton
Silicified Wenlock trilobites representing at least fifteen genera are reported from argillaceous carbonates within the upper beds of the Whittaker Formation and lower beds of the Delorme Formation, Delorme Range, south-western District of Mackenzie, Canada. The associated brachiopod fauna is of low diversity (six genera), small physical size, and is dominated by neanic stages of development. Elements of this brachiopod fauna are poorly known elsewhere in north-western Canada. The trilobites were derived from five collections spanning 125 m (410 ft) of strata; the most diverse faunas are from the lower 15m (50 ft) of the trilobite bearing interval. The trilobite collections are bounded by conodont faunas representative of the Pterospathodus amorphognathoides Zone below and the Pedavis latialata Zone 116m (380 ft) above the youngest trilobite collection. The fauna is generically dominated by cheirurids and odontopleurids. Scutelluids, phacopids, dalmanitids, and harpids are absent from our collections. New taxa described are: Otarion brauni, Scharyia redunzoi, Deiphon braybrooki, Youngia copelandi, Encrinurus (Fragiscutum) dimitrovi, Acidaspis jessi, and Diacanthaspis (Acanthalomina) thorsteinssoni.