Cretaceous sponges from the Campanian of Misburg and Höver
Rhizopoterion Zittel 1877

Locality:     Alemannia, Höver.
Height: 100 mm

Rhizopoterion tubiforme

Schrammen 1910

Rhizopoterion tubiforme is an uncommon species at Höver and is almost absent in the Upper Campanian of Misburg. Rhizopoterion tubiforme is similar to the more common Ventriculites sp., but has a thicker wall (up to 10 mm), more slit-like and less systematically arranged ostia and more pronounced longitudinal ridges on its dermal side.