Serometacoceras Korn & Ghaderi 2025

Genus Serometacoceras Korn & Ghaderi, 2025 Type species Pleuronautilus Verae von Arthaber, 1900: 216; original designation. Diagnosis Genus of the family Metacoceratidae with a subinvolute or subevolute conch; whorl profile equidimensional or more or less strongly depressed, usually trapezoidal with weakly divergent flanks. Venter usually weakly convex or flattened; ventrolateral shoulder narrowly or broadly rounded. Umbilical margin pronounced and subangular in the intermediate growth stage, rounded in the adult stage. Sculpture with conical nodes on the ventrolateral shoulder or on the umbilical margin or both, sometimes connected by low ribs on the flank. Suture line with a shallow external lobe or a very low external saddle and a broadly rounded lateral lobe; without annular process. Siphuncle small with subcentral position ventrad of septum centre (from Korn & Ghaderi 2025). Included species Transcaucasia and NW Iran (Abich 1878; von Arthaber 1900; Shimansky 1965; Kotlyar et al. 1989; Korn & Ghaderi 2025): Nautilus dorso armatus Abich, 1878, Wuchiapingian, Azerbaijan; Nautilus tubercularis Abich, 1878, Wuchiapingian, Azerbaijan; Nautilus incertus Abich, 1878, Wuchiapingian, Azerbaijan; Pleuronautilus Verae von Arthaber, 1900, Wuchiapingian, Azerbaijan; Metacoceras dorashamense Shimansky, 1965, Wuchiapingian, Azerbaijan; Pleuronautilus dzhulfensis Shimansky, 1965, Wuchiapingian, Azerbaijan [synonym of Serometacoceras verae]; Pleuronautilus costalis Shimansky, 1965, Wuchiapingian, Armenia; Pleuronautilus dzhagadzurensis Zakharov in Kotlyar et al., 1989, Capitanian, Azerbaijan; Serometacoceras inflatum Korn & Ghaderi, 2025, Wuchiapingian, NW Iran; Serometacoceras cingulum Korn & Ghaderi, 2025, Wuchiapingian, NW Iran; Serometacoceras parvituberculatum Korn & Ghaderi, 2025, Wuchiapingian, NW Iran; Serometacoceras arasense Korn & Ghaderi, 2025, Changhsingian, NW Iran. Central Iran (this paper): Serometacoceras pentagonum sp. nov., Wuchiapingian. Pakistan (Waagen 1879; Reed 1931, 1944): Nautilus latissimus Waagen, 1879, Wuchiapingian, Salt Range; Gyroceras Medlicottianum Waagen, 1879, Wuchiapingian, Salt Range; Metacoceras warchense Reed, 1931, Wuchiapingian, Salt Range; Metacoceras chittidilense Reed, 1944, Wuchiapingian, Salt Range; Parametacoceras venustum Reed, 1944, Wuchiapingian, Salt Range. South China (Xu 1977; Zheng 1984; Ma 1997): Metacoceras hunanense Xu, 1977, Changhsingian, Hunan; Pleuronautilus changxingensis Zhao, Liang & Zheng, 1978, Changhsingian, Zhejiang; Pleuronautilus zhongyingensis Zheng, 1984, Changhsingian, Guizhou; Pleuronautilus magnus Zheng, 1984, Changhsingian, Guizhou; Pleuronautilus anfuensis Ma, 1997, Wuchiapingian, Jiangxi; Pleuronautilus curvatus Ma, 1997, Wuchiapingian, Jiangxi; Pleuronautilus robustus Ma, 1997, Wuchiapingian, Jiangxi. Remarks Korn & Ghaderi (2025) placed the morphocline with “ Nautilus dorso armatus ” and “ Pleuronautilus Verae ” entirely in the genus Serometacoceras. Some representatives of these Late Permian forms, previously attributed to Pleuronautilus, do in fact have a sculpture very reminiscent of Pleuronautilus, but they lack the annular process. They may also belong to Serometacoceras.