Paralytoceras Frech 1902

Genus Paralytoceras Frech, 1902 Type species Clymenia crispa Tietze, 1870: 135, by monotypy. Genus diagnosis Genus of the subfamily Pseudarietitinae with a circular or compressed whorl profile with raised ventral keel that is sometimes paralleled by two longitudinal grooves. Sculpture with collar-like ribs and spiral ornament. Genus composition Central Europe (Tietze 1870): Clymenia crispa Tietze, 1870. South China (Ruan 1981): Pseudarietites lenticulus Ruan, 1981; Pseudarietites tricarinatus Ruan, 1981. Remarks Paralytoceras can clearly be separated from the other genera of the Pseudarietitinae by its sculpture, consisting in the middle ontogenetic stage of a succession of collar-like riblets that are often crenulated and cause a conspicuous spiral ornament. The genus could be related to Pseudarietites, as some of the Paralytoceras species show a very similar ventral shape with longitudinal grooves paralleling a raised ventral keel. Specimens of Paralytoceras belong to the rarest Early Tournaisian ammonoids and are known from only few places worldwide (Lower Silesia, Rhenish Mountains, Guizhou). In all regions they occur in extremely low numbers; only two specimens of the type species are known from the type locality at Dzikowiec in Lower Silesia.Only a few fragmentary specimens are preserved from the Oberrödinghausen railway cutting.Published as part of Korn, Dieter & Weyer, Dieter, 2023, The ammonoids from the Gattendorfia Limestone of Oberrödinghausen (Early Carboniferous; Rhenish Mountains, Germany), pp. 1-230 in European Journal of Taxonomy 882 on page 189, DOI: 10.5852/ejt.2023.882.2177, http://zenodo.org/record/817758