Genus Tropidoturris Kilburn, 1986

Type species: Pleurotoma (Drillia) scitecostata Sowerby, 1903

Remarks. According to Kilburn (1986), Tropidoturris is an endemic genus represented by five species and one subspecies from the continental shelf and slope of southeastern Africa. The genus is morphologically very distinctive being characterized by its biconical shape, strong shoulder keel, deep anal sinus and paucispiral protoconch. Kilburn (1986: 645) compared Tropidoturris with Corinnaeturris Bouchet & Warén, 1980 and Carinotropis Bernasconi & Robba, 1984. However, members of Corinnaeturris have shouldered but not keeled teleoconch whorls, a granulose surface, and carinate protoconch whorls. The genus Corinnaeturris is currently assigned to the family Clathurellidae H. Adams & A. Adams, 1858. Similarly, Carinotropis, based on Carinotropis nitida Bernasconi & Robba, 1984 from the Pliocene of Italy (considered by Della Bella & Scarponi (2007) a junior synonym of the Miocene Drillia michelottii var. minima Montanaro, 1937) has a carinate protoconch and a much shorter base than Tropidoturris. In Tropidoturris scitecostata (Sowerby, 1903), type species of the genus, the sculpture is predominantly axial while in other members, such as T. fossata notialis Kilburn, 1986, T. simplicicingula simplicicingula (Barnard, 1958), T. simplicicingula pondo Kilburn, 1986 and T. planilirata Kilburn, 1986, it is spiral. In T. fossata (Sowerby, 1903) and T. anaglypta Kilburn, 1986 the axial ribs are weak and “crenellate the shoulder keel” (Kilburn, 1986: 645). Operculum and radula were described by Kilburn (1986: 645).