Original paper
New and revised Cyrtoclymenioidea (Clymeniida, Ammonoidea, Famennian, Upper Devonian)
Becker, R. Thomas
Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen (2025)
160 references
published online: Dec 4, 2025
manuscript accepted: Nov 7, 2025
manuscript received: Apr 29, 2025
DOI: 10.1127/njgpa/1294
Abstract
The species-rich superfamily Cyrtoclymenioidea is the longest-ranging of all clymeniid superfamilies, characterized by mesodomic, subevolute to subinvolute conches and often simplified sutures. Taxonomic revisions and the separation of genera with distinctive growth ornament, cross-sections, and specific stratigraphical ranges have long been neglected. As a preparation for the future Devonian Ammonoid Treatise, new genera are proposed and typical species are revised, which includes the first description of rare new forms. Within the Cyrtoclymeniidae, new and described taxa include Prorsiclymenia n. gen., with the type species Clymenia involuta Wedekind, 1908 and Prorsi. crassa (Wedekind, 1914), Lineaclymenia n. gen., with the type species Protactoclymenia cara Nikolaeva & Bogoslovsky, 2005a and Rectoclymenia rotundata Schindewolf, 1923b, Cyrtoclymenia vermillionensis n. sp., Cyrto. riemkensis n. sp., Paracyrtoclymenia n. gen., with the type species Cyrto. strigata House, 1962, Paracyrto. hagenensis n. gen. n. sp., Paracyrto. campanulata (Richter, 1848), and Paracyrto. aff. campanulata, Nummoclymenia n. gen., with the type species Nummo. planata n. gen. n. sp., Rhenoclymenia n. gen., with the type species Clymenia phillipsi Wedekind, 1908, and Plicoclymenia n. gen., with the type species Clymenia cincta Münster, 1839, Clymenia plicata Münster, 1839, Clymenia fasciata Phillips, 1841, Plico. aff. fasciata, and Plico. cadiconica n. gen. n. sp. Protactoclymenia is subdivided into four species groups that may warrant future (sub)genus-level distinction. Rhenish representatives of the typical Protacto. pulcherrima Group are revised. The small-sized Protacto. pinnata Group includes Protacto. franconica n. sp. Within the strictly oxyconic Rectoclymeniidae, Rectoclymenia is divided into Rectoclymenia s. str., comprising only species with convex to weakly biconvex growth lines, e.g. Recto. intercostata n. sp. and Recto. aff. fraudulenta Nikolaeva & Bogoslovsky, 2005a, and Lanceoclymenia n. gen., characterized by markedly concavo-convex ornament, with the type species Clymenia subflexuosa Münster, 1840. This new genus also includes Lanceo. kaufmanni n. sp. and Lanceo. dziki nov. nom., established for Cyrtoclymenia acuta in Dzik (2006). The true Cyrto. acuta Schmidt, 1924 is designated the type species of Schmidtoclymenia n. gen., which is probably congeneric with some uppermost Famennian taxa from South China. Limoclymenia n. gen., with the type species Cyrto. tetragona Schmidt, 1924, Limo. n. sp. aff. tetragona, and Limoclymenia n. sp., is placed with some reservation in the Genuclymeniinae (Cymaclymeniidae). In the same subfamily, Rectoclymenia retrusa Czarnocki, 1989 is the type species of Sanctaclymenia n. gen., represented in southern Morocco by the rare Sancta. extrema n. gen. n. sp. and in the Kellerwald by Sanctaclymenia n. gen. n. sp. Sigmoclymenia brueggei n. sp. is established for the supposed Falciclymenia falcifera from Thuringia described by Brügge (1973). The Hoeveliidae are included in the Cyrtoclymenioidea and are represented at the famous Enkeberg locality (eastern Sauerland) by Beulia langei n. sp. Zoobank registration: urn:lsid:zoobank.org:pub:1CCDCC06-432F-4E62-9115-A2041DCF4AA5.
Keywords
Ammonoidea • Clymeniida • Upper Devonian • taxonomy • biostratigraphy • systematics