Cocks and Rong (1989) subdivided the species of the Ordovician brachiopod genus Bimuria into two groups, those with a simple, or not undercut, cardinal process and those with an undercut cardinal process. They placed the second group in a new genus, Cooperea, and grouped Cooperea with Craspedelia in the new subfamily Craspedeliinae of the family Sowerbyellidae. However, the cardinal process of Bimuria ranges from not undercut to undercut within at least two species. Cooperea is therefore placed in synonymy with Bimuria, and Craspedelia is returned to the Bimuriidae.Cocks and Rong (1989) inferred that, with rare exceptions, the cardinal process of the Plectambonitacea evolved from simple to trifid to undercut. The evidence from Bimuria indicates, however, that the undercut process developed more than once and, in Bimuria, directly from the simple type.As an adjunct to the above discussion three new species are described: Bimuria gilbertella, Craspedelia intonsa, and Craspedelia sp. 1. Craspedelia is a rarely reported genus documented here for the first time in western North America (northern California). Additional evidence is introduced that the ratio Lmusbv/Lebv decreased from middle to late Ordovician species of Bimuria.
Three new species of Glossobalanus (Hemichordata: Enteropneusta: Ptychoderidae) from western North America
