{{Short description|Subfamily of gastropods}} {{Automatic Taxobox | image = Medusafissurella dubia 001.jpg | image_caption = A shell of ''Medusafissurella dubia'' | taxon = Fissurellinae | authority = Fleming, 1822 }}
The subfamily '''Fissurellinae''', common name the '''keyhole limpets''' and '''slit limpets''', is a taxonomic subfamily of limpet-like sea snails, marine gastropod molluscs in the family Fissurellidae.
Of the three subfamilies in the Fissurellidae, the subfamily Fissurellinae is the most recently evolved; its earliest known species date back to the Cenozoic.<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|archive-date=2010-07-21|archive-url=https://web.archive.org/web/20100721003210/https://www.nhm.org/site/sites/default/files/pdf/contrib_science/CS379.pdf|url-status=dead}}</ref>
The following genera in this subfamily have characteristically a body that tends to be larger than the shell. *''Amblychilepas'' * ''Dendrofissurella'' * ''Medusafissurella'' They have sometimes been confused with genera in the emarginuline tribe Fissurellideini.
Other genera include : ''Altrix'' -'' Clathrosepta'' - ''Cornisepta'' - ''Cosmetalepas'' -'' Dendrofissurella'' - ''Elegidion'' (synonym of ''Diodora'' <small>J. E. Gray, 1821</small>) - ''Fissurella'' - ''Laevinesta'' - ''Lucapina'' -'' Macroschisma'' - ''Manganesepta'' - ''Montfortula'' - ''Montfortulana'' - ''Parmaphoridea'' - ''Parmophoridea'' - ''Profundisepta''
The characteristics that distinguish them from the subfamily Emarginulidae are the following : * the rachidian plate of the radula has a broad base and a narrow tip * the outer lateral tooth in the radula is so long that it is aligned with the lateral teeth from the row above * the shell muscle lacks an inwardly directed hook-shaped process.
A molecular phylogeny however has shown that Fissurellinae (''Diodora'' and ''Fissurella'' were examined) is paraphyletic with respect to Emarginulinae. This is somewhat surprising as the subfamily Emarginulinae (shells with an open slit) is generally accepted to be basal to the subfamily Fissurellinae (shells with an apical opening) <ref>{{cite journal|last=Geiger|first=Daniel L.|author2=Christine E. Thacker|title=Molecular phylogeny of Vetigastropoda reveals non-monophyletic Scissurellidae, Trochoidea, and Fissurelloidea|journal=Molluscan Research|volume=25|issue=1|pages=47–55|url=https://www.mapress.com/mr/content/v25/2005f/n1p055.pdf}}</ref>
==References== {{Reflist}}
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Category:Fissurellidae Category:Taxa named by John Fleming (naturalist)