Paralytoceras Frech, 1902

Korn, Dieter & Weyer, Dieter, 2023, The ammonoids from the Gattendorfia Limestone of Oberrödinghausen (Early Carboniferous; Rhenish Mountains, Germany), European Journal of Taxonomy 882, pp. 1-230 : 189

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.