Middle to Upper Cambrian linguliformean brachiopods from the Deadwood Formation of subsurface Alberta and Saskatchewan, Canada

Abstract

Limestone beds intercalated within a succession of sandstones, siltstones, and shales of the subsurface Deadwood Formation, cored in two wells in Alberta and Saskatchewan, yielded twelve species assigned to eight genera of organophosphatic brachiopods (Subphylum Linguliformea). The nine species recovered from the Alberta well are Marjuman (late Middle to early Late Cambrian) in age. Three of these species,Neotreta davidiPopov, Berg-Madsen, and Holmer, 1994;Picnotreta debilisHenderson and MacKinnon, 1981; andStilpnotreta magnaHenderson and MacKinnon, 1981, are associated with the Mindyallan (early Late Cambrian) of Queensland, and are previously unknown from Laurentia. This brachiopod fauna occurs with a diverse fauna of paraconodont species. The Saskatchewan well yielded three species ofLinnarssonella, belonging to the upper Steptoean to the lower Sunwaptan (middle Late Cambrian). One new subfamily, Neotretinae, is erected, and two new species,Rhondellina albertensis, andLinnarssonella tubiculaare described.Linnarssonella elongataBell, 1941, is reinstated as a valid species. This fauna occurs with a diverse fauna of paraconodont species and is overlain, 226 feet higher, by conodonts of the Early SunwaptanProconodontusZone.