Cymaclymenia Hyatt, 1884

Klein, C. & Korn, D., 2014, A morphometric approach to conch ontogeny of Cymaclymenia and related genera (Ammonoidea, Late Devonian), Fossil Record 17 (1), pp. 1-32 : 12-13

Cymaclymenia Hyatt, 1884

Type species: Clymenia striata Münster, 1843, p.11 (original designation).

Genus definition: Genus of the Cymaclymeniidae with pointed, strongly asymmetric lateral lobe. Course of the growth-lines biconvex.

Discussion: Cymaclymenia is one of the most species-rich Devonian ammonoid genera; Korn and Klug (2002) listed 40 species within the genus, of which several were regarded as synonymous. A further seven new species were added by Nikolaeva and Bogoslovsky (2005) to Cymaclymenia , but three of these can be regarded as probably belonging to Procymaclymenia , a genus ignored by these authors. This large amount of morphologically similar forms is an obstacle for a clear separation of species, of which only few have been described including the conch ontogeny. Furthermore, the precise stratigraphic occurrence is not known for many species for which, if at all, only the stage is known.

The material of Cymaclymenia from Morocco and Algeria has traditionally (e.g. Petter, 1960; Korn, 1999; Becker et al., 2002) been assigned to species previously described from central Europe (e.g. Franconia, Rhenish Mountains). In fact there is some resemblance, but at the same time there are differences when well-preserved material is studied and compared. Generally it appears that the material from the Anti-Atlas has a weaker shell ornament when compared with the European species, while differences in conch geometry and suture lines are only minor. The differences in shell ornament are used here as a criterion for the separation of new species within the genus, giving the cymaclymeniid faunas from North Africa an exotic character containing endemic species.

A concept of largely endemic faunas has been used by Nikolaeva and Bogoslovsky (2005), who besides using names from central European species, named four new species from the South Urals and central Kazakhstan.