Madeiranzonia gibbera is a species of minute sea snail, a marine gastropod mollusc or micromollusc in the family Rissoidae. It is the only species in the genus Madeiranzonia.
References
External links Watson R. B. (1873). On some marine mollusca from Madeira, including a new genus of the Muricinae, a new Eulima and the whole of the Rissoa of the group of islands. Proceedings of the Zoological Society of London (1873): 361-391 MNHN, Paris: syntype