Genus Rineceras Hyatt, 1893

Type species

Gyroceras propinquum de Koninck, 1880; subsequent designation by Foord (1900).

Diagnosis

Genus of the family Trigonoceratidae with evolute conch; whorls detached or slightly in contact; whorl profile elliptical or rounded triangular with broad venter. Ornament with coarse growth lines and coarse spiral ridges; coarse granulation at the crossing points of growth lines and spiral ridges. Suture line with shallow external and lateral lobes. Siphuncle small with subcentral position (after Kummel 1964; emended).

Included Early Carboniferous species

Rhineceras alapaevskensis Kruglov, 1934, Urals; Pararineceras balladoolense Turner, 1954, Isle of Man; Nautilus canaliculatus von Eichwald, 1857, south Urals; Rineceras carinatiforme Shimansky, 1967, Kazakhstan; Nautilus carinatus von Eichwald, 1857, western Russia; Nautilus (Discus) digonus Meek & Worthen, 1860, Indiana; Nautilus Luidii Fleming, 1828, Derbyshire; Nautilus (Trematodiscus) Meekianus Winchell, 1862, Michigan; Gyroceras Meyerianum de Koninck, 1844, Belgium; Rineceras multituberculatum sp. nov., Algeria; Rineceras ohioense Miller & Garner, 1953, Ohio; Triboloceras patteiskyi Schmidt, 1951, Rhenish Mountains; Gyroceras propinquum de Koninck, 1880, Belgium; Rineceras rectangulatum sp. nov., Algeria; Nautilus rhenanus Holzapfel, 1889, Rhenish Mountains; Nautilus (Trematodiscus) strigatus Winchell, 1862, Michigan.

Remarks

Turner (1954) introduced the genus Pararineceras on the basis of the species originally described by Martin (1793, 1809) as “Conchyliolithus N. Ammonites (Luidii)”, but as Martin did not follow the Linnaean binomial procedure, Fleming (1828) is regarded as the author of the species (Turner 1953). This species differs from most of the species assigned to the genus Rineceras only by the more densely coiled conch, a character that might be gradual and not useful for a separation of genera. While Kummel (1964) accepted both of the two genera, Shimansky (1967) and Dzik (1984) regarded Pararineceras as a synonym of Rineceras . In the following, we treat Pararineceras a junior synonym of Rineceras until a clear separation can be demonstrated.

Stratigraphic range

Middle Tournaisian to Serpukhovian.