The Echinoid Directory

Rhenechinus Dehm, 1953, p. 88

Diagnostic Features	Test large; shape unknown; plating apparently thin and imbricate. Apical disc unknown. Ambulacra narrow and straight; quadriserial with every second plate small and occluded from the perradial suture. Pore-pairs small and uniform, alternately displaced to left and right forming a biseries down the centre of each half ambulacrum. Interambulacral zones broad and composed of a large number of small, polygonal plates forming semi-regular en chevron rows. Individual plates with small secondary tubercles or granules only. Peristome small. Lantern present, structure unknown. Spines short, simple.
Distribution	Middle Devonian (Eifel), Germany.
Name gender	masculine
Type	Rhenechinus hopstatteri Dehm, 1953, by original designation.
Species Included	Only the type species.
Classification and/or Status	Stem group Echinoidea; Echinocystitidae. Monotypic.
Remarks	Distinguished from Porechinus by its quadriserial ambulacral plating and more irregular array of interambulacral plates. Very close to Echinocystites, but in that taxon the interambulacral plates are more scale-like and more irregular in arrangement. Dehm, R. 1953. Rhenechinus hopstatteri nov. gen., nov. sp., ein Seeigel aus dem rheinischen Unter-Devon. Notizblatt des Hessischen Landesamtes fur Bodenforschung zu Wiesbaden 81, 88-95, pl. 5.