Cyclothyris elegans (VON HANSTEIN, 1879) and Cretirhynchia tenuicostata (VON HANSTEIN, 1879), two valid Lower Maastrichtian rhynchonellid brachiopods from the phosphatic chalk of Ciply, Belgium

This paper presents an emended description and illustrations of Cyclothyris elegans (VON HANSTEIN, 1879) and of Cretirhynchia tenuicostata (VON HANSTEIN, 1879). Lectotypes have been chosen. This Cyclothyris and this Cretirhynchia are distinct and valid species. Cyclothyris elegans is an uncommon species in the Lower Maastrichtian phosphatic chalk of Ciply [ Belemnella obtusa Zone] whereas Cretirhynchia tenuicostata is a much more common species.