Middle Devonian uncinuloids (Brachiopoda, Rhynchonellida) from North Africa and Central Europe

Abstract

The paper includes a taxonomic revision of four externally similar Middle Devonian rhynchonellide species from northwestern Africa (Maïder, Tindouf Syncline) and Central Europe (Eifel, Bergisches Land, Holy Cross Mts.), considered in recent papers as representatives of Kransia Westbroek, 1967 or Nalivkinaria Rzhonsnitskaya, 1968. All four possess a septalium and a multilamellate cardinal process, the assignment to Nalivkinaria, having a bifid cardinal process, is therefore clearly inappropriate. Lebanzuella? issoumourensis (Drot, 1971) is present in the Givetian of Africa; two subspecies, L.? issoumourensis issoumourensis from Jbel Issoumour and L.? issoumourensis smarensis ssp. nov. from Western Sahara, are distinguished by their biometric characteristics. The other two species are included in Kransia (Fatimaerhynchia) subgen. nov. differing from Kransia (K.) in the presence of a septalium; the occurrence of such a variable structure is considered to be justification for distinction at the subgenus level. Kransia (Fatimaerhynchia) goldfussii (Schnur, 1853) is an Eifelian species. Kransia (Fatimaerhynchia?) aff. goldfussii from the Givetian of Bilveringsen is a separate species (larger, more transverse, more strongly ornamented), which is not described because of insufficient material. Kransia (Fatimaerhynchia) signata (Schnur, 1851) is present in the Middle Devonian of Jbel Issoumour, the middle Eifelian of the Eifel and the (upper?) Givetian of the Holy Cross Mountains.