The ammonoids from the Gattendorfia Limestone of Oberrödinghausen (Early Carboniferous; Rhenish Mountains, Germany) Author Korn, Dieter 286CA4F3-7EBC-4AEF-A66A-B2508D001367 Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Invalidenstrasse 43, 10115 Berlin, Germany. dieter.korn@mfn.berlin Author Weyer, Dieter A09A1738-C70E-4F22-A069-8B7DB4A1753D Museum für Naturkunde, Leibniz-Institut für Evolutions- und Biodiversitätsforschung, Invalidenstrasse 43, 10115 Berlin, Germany. dieter.weyer@t-online.de text European Journal of Taxonomy 2023 2023-07-19 882 1 230 http://dx.doi.org/10.5852/ejt.2023.882.2177 journal article 58033 10.5852/ejt.2023.882.2177 57d1d191-2bf5-4229-a0f5-9ab472a114a6 2118-9773 8177581 67C909E4-C700-4F8D-B8CE-5FD9B2C5D549 Genus Costimitoceras Vöhringer, 1960 Type species Costimitoceras ornatum Vöhringer, 1960: 148 ; original designation. Genus diagnosis Genus of the Acutimitoceratinae with a discoidal conch and moderately high to high coiling rate (WER = 1.90–2.20); inner whorls evolute. Ornament with biconvex growth lines and spiral lines. Suture line with deep external lobe. Genus composition Central Europe ( Vöhringer 1960 ): Costimitoceras ornatum Vöhringer, 1960 . North Africa( Ebbighausen & Bockwinkel 2007 ): Costimitoceras aitouamar Ebbighausen& Bockwinkel, 2007 . South China ( Ruan 1981 ): Imitoceras ( Costimitoceras ) epichare Ruan, 1981 . Remarks Costimitoceras can be easily distinguished from all other prionoceratids due to the very striking combination of coarse growth lines and spiral lines.