Brasilia geisingensis (Dietze 2014)

17cm. This was a rather convoluted ID. First of all it was named Brasilia similis maubeugi but in December 2014 it was revised by Dietze etal to the above identification. From the Upper Aalenian at Geisingen. Calcite core. No, that's not a tooth in the middle but rather an interestingly formed concretion.