Planaxids are known as clusterwinks because of their habit of clustering together in concealed, moist locations when the tide is out. They have conical shells resembling periwinkles, except for the wide, shallow anterior canals. They brood their embryos in a chamber behind their heads, releasing them into the sea as veliger larvae to form part of the plankton.[2]
^Mahmoud, L.G. Etudes paleontologiques sur la fauna Cretacique du Massif du Moghara (Sinai-Egypte). Publications de I'Institut du Desert d'Egypte 8, 1956
^ abBeechey, Des (2008). "Family Planaxidae". The Seashells of New South Wales. Retrieved 2014-12-21.
^Houbrick R. S. (1987). "Anatomy, Reproductive Biology, and Phylogeny of the Planaxidae (Cerithiacea: Prosobranchia)". Smithsonian Contributions to Zoology445.
Strong E.E., Colgan D.J., Healy J.M., Lydeard C., Ponder W.F. & Glaubrecht M. (2011) Phylogeny of the gastropod superfamily Cerithioidea using morphology and molecules. Zoological Journal of the Linnean Society 162: 43–89.
Bouchet P., Rocroi J.P., Hausdorf B., Kaim A., Kano Y., Nützel A., Parkhaev P., Schrödl M. & Strong E.E. (2017). Revised classification, nomenclator and typification of gastropod and monoplacophoran families. Malacologia. 61(1-2): 1–526.