Medusafissurella

{{Short description|Genus of gastropods}} {{Automatic taxobox |image = Medusafissurella dubia 002.jpg |image_caption = ''Medusafissurella dubia'' |taxon = Medusafissurella |authority = Mclean and Kilburn, 1986 |synonyms_ref= |synonyms= |type_species= ''Fissurella salebrosa'', Reeve, 1850 |display_parents= 3 }}

'''''Medusafissurella''''' is a genus of minute deepwater keyhole limpets, marine gastropod mollusks or micromollusks in the family Fissurellidae, the keyhole limpets and slit limpets.<ref>{{cite journal|last=McLean |first=James H.|author2=R.N. Kilburn|title=Propodial elaboration in Southern African and Indian Ocean Fissurellidae (Mollusca, Prosobranchia) with description of two new genera and one new species|journal=Contributions in Science|date=September 1986|volume=379|pages=1–12 |doi=10.5962/p.208123 |s2cid=135095660 |url=http://www.nhm.org/site/sites/default/files/pdf/contrib_science/CS379.pdf|accessdate=2010-07-19}}</ref><ref name="WoRMS">Bouchet, P.; Gofas, S. (2012). Medusafissurella McLean & Kilburn, 1986. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=536032 on 2013-01-17</ref>

==Etymology== In Greek mythology Medusa was a Gorgon, a monster with snakes for hair. The radiating tentacles in ''Medusafissuralla'' recall the serpentine locks of this monster.

==Description== ''Medusafissurella'' is closely associated with ''Amblychilepas'' and ''Dendrofissurella'' with which it shares radular and shell characters. But ''Medusafissurella'' has a smaller body than the species in ''Amblychilepas'', the genus to which it was previously assigned.

The body of species in ''Medusafissurella'' is larger than the shell. The anterior part of the shell is raised but is markedly narrowed. This character distinguishes ''Medusafissurella'' from most species in the genus '' Fissurella''. The edge of the anterior shell is thinner and sharper than in the rest of the shell. The posterior end of the shell is not raised at all or only slightly raised. The opening at the apex (''foramen'') has an oval shape. The sculpture of the shell shows strong, scabrous ribs (= transverse folds) giving the impression of a rough surface with minute ribs. This character sets ''Medusafissurella'' apart from ''Amblychilepas'' and ''Dendrofissurella''

The posterior portion of the foot is covered by the shell. The mantle folds only slightly envelop the edge of the shell. The foot also shows elaborate propodial processes at the ''propodium'' (front part of the foot) with numerous subequal (= nearly equal) radiating tentacles, that are sometimes branched, while in ''Dendrofissurella'' the tentacles have a single, main branching structure. The function of these tentacles is not well understood. They may serve to trap or hold food, but then they would be better attached to the snout above them instead of being attached to the propodium. The large outer lateral tooth of the radula is quadricuspid ( = with four cusps). The eyes are situated at the base of the cephalic tentacles.

==Species== * ''Medusafissurella chemnitzii'', (Sowerby I, 1835): East Africa and Arabian Sea * ''Medusafissurella dubia'' Reeve, 1849: Southern and eastern Africa * ''Medusafissurella melvilli'' (Sowerby III, 1882) * ''Medusafissurella salebrosa'' (Reeve, 1850): Southwestern Africa ; Species brought into synonymy: * ''Medusafissurella gallagheri'' Smythe, 1988: synonym of ''Medusafissurella melvilli'' (G. B. Sowerby III, 1882)

==References== {{Commons category|Medusafissurella}} {{Reflist}}

Category:Fissurellidae Category:Gastropods described in 1986 Category:Taxa named by Richard Kilburn