Article: A redescription of the anomalocystitid mitrate Rhenocystis latipedunculata from the Lower Devonian of Germany

The anomalocystitid mitrate Rhenocystis latipedunculata, from the Lower Devonian Hunsruckschiefer of Rhineland, Germany, is reconstructed and redescribed. Rhenocystis is characterized by transverse, terrace-like ridges on two antero-posteriorly elongate, postero-lateral areas of the dorsal head skeleton and on the posterior third of the ventral head skeleton; the relatively small size of the ventral plates of the second transverse row; a suture between the mid-ventral plates of the first and third row; the relatively large size of the placocystid plate; the presence of rocking articulations between dorsal and ventral fore tail plates; a transversely expanded and recumbent anterior styloid blade; a robust, spike-like posterior blade; and four morphologically distinct regions in the hind tail. Rhenocystis closely resembles Placocystites forbesianus from the middle Silurian of England and Victoriacystis wilkinsi from the upper Silurian of Australia, with which if forms a clade within the anomalocystitids of boreal type.