Revision of <i>Monopteria</i> (Monopteriidae), a late Paleozoic pteriomorphian bivalve

Abstract Species of Monopteria are revised to include documentation of substantial change in shell shape during growth, characters of the hinge, and characters present on the anterior surface of the shell. The mature shell grew in an arcuate curve that elongates far to the posterior and has a wide sinus that separates the inflated shell body from a prong-like posterior auricle on the hinge line. An unusual depression of the paired valves (anterior depression) is present on the anterior surface surrounding a large byssal notch. Dentition is lacking, and a clinovincular ligament (new term) is present. Species occur mostly in mollusk-rich biotas of shallow marine environments. Species lived with a combination of byssal attachment and a rounded ventral surface that enabled them to maintain position within fine-grained sediment. Six species are recognized, and five are provided with new or revised descriptions. New species include M. magna and M. heaneyi , neotypes are designated for M. longispina Cox, 1857 and M. alata Beede, 1898, and a lectotype is designated for M. marian White, 1874. Species Gervillia auricula Stevens, 1858, and Anthracoptera polita White, 1880, previously considered to be included in the genus, are excluded from Monopteria and the name Gervillia auricula is judged to be without merit and abandoned. The use of genus name Limopteria as a replacement of Monopteria is shown to be invalid. Limopteria is not a valid name; it has never been proposed as a taxon in publication. http://zoobank.org/bd1064f1-f576-4194-8405-7d0c7771bc82