The systematics of postibullinid edrioasteroids

An examination of Devonian through Pennsylvanian postibullinid edrioasteroi ds indicates the presence of two clades in the monophyletic subfamily Posti bullinae, new subfamily. Postibulla is characterized by the presence of a p osterior oral protuberance and a cover plate pattern with three primary pla tes and includes Postibulla legrandensis, P. lukei, P. keslingi, P. neglect a, and P. alabamaensis new species. Parapostibulla new genus is characteriz ed by double biserial cover plates, the lack of the posterior oral protuber ance, and an unusual hydro-gonopore, and includes Parapostibulla hybolopus (Fraunfelter and Utgaard, 1970), P. murphyi new species and Parapostibulla species A. Additional poorly-preserved edrioasteroids are illustrated from the Missourian and Virgilian of Kansas and Iowa that are the youngest known from North America.