Aulacopleurine trilobites from the Llandovery of northwestern Canada

Abstract

Aulacopleurine trilobites from Llandovery strata of the Whittaker Formation in the central Mackenzie Mountains, Northwest Territories, Canada, include Aulacopleura andersoni n.sp., Aulacopleura? ranfordi n.sp., and Songkania smithi n.sp. The subfamily Aulacopleurinae consists of only the genera Aulacopleura Hawle and Corda, 1847, and Songkania Chang, 1974, characterized by smooth, broad early growth stages and holaspides having expanded frontal and genal areas, covered with dense caecal pits, but usually very subdued tuberculate sculpture. The relationship of Aulacopleura? ranfordi and A.? reedi Pribyl, 1947, to the remainder of species assigned to the genus is ambiguous. -Authors