{{Short description|Species of gastropod}} {{Use dmy dates|date=June 2020}} {{Speciesbox | name = ''Addisonia excentrica'' | image = Addisonia excentrica 01.JPG | image_caption = Five views of ''Addisonia excentrica'' | taxon = Addisonia excentrica | authority = (Tiberi, 1855) | synonyms_ref = <ref name="WoRMS" /> | synonyms = * ''Addisonia enodis'' <small>Simone, 1996</small> * ''Addisonia excentros'' <small>Jeffreys 1884</small> * ''Addisonia lateralis'' <small>(Requien, 1848)</small> * ''Addisonia lateralis'' var. ''paradoxa'' <small>Dall, 1882</small> * ''Addisonia paradoxa'' <small>Dall, 1882</small> * ''Gadinia lateralis'' <small>Requien 1848</small>1 * ''Gadinia excentrica'' <small>Tiberi 1855</small> * ''Tylodina excentrica'' <small>Monterosato 1872</small> }}

'''''Addisonia excentrica''''' is a species of sea snail, a marine gastropod mollusk in the family Addisoniidae.<ref name="WoRMS">{{WRMS species|138699|''Addisonia excentrica'' (Tiberi, 1855)||25 October 2010}}</ref>

==Distribution== This species can be found in European waters and in the Mediterranean Sea.

== Description == The maximum recorded shell length is 20.3&nbsp;mm.<ref name="Welch 2010">Welch J. J. (2010). "The "Island Rule" and Deep-Sea Gastropods: Re-Examining the Evidence". ''PLoS ONE'' '''5'''(1): e8776. doi:10.1371/journal.pone.0008776.</ref> The size of the ovate shell varies between 8&nbsp;mm and 20&nbsp;mm. It is thin and whitish. The apex presents an appearance as if an embryonic tip (perhaps spiral) had fallen and been replaced by a peculiarly blunt ovate apex, which in the young shell is nearly marginal, posterior and to the left of the middle line, but in the adult is considerably within the margin, curved downward and backward and much more asymmetrical. The sculpture of the shell shows faint grooves radiating from the (smooth) apex and reticulated by the stronger concentric lines of growth, beside which the extremely inflated arch of the back is somewhat obscurely concentrically waved. The shell has a polished appearance over the sculpture. The thin margins are sharp. The interior of the shell is smooth and somewhat polished. The scar of the pedal muscle is narrow and at a considerable distance within the margin. The anterior ends of the scar are enlarged and hooked backward on their inner edges. These ends are connected by a line broadly arched forward and marking the attachments of the mantle to the shell over the head.<ref>[https://archive.org/stream/manualconch12tryorich/manualconch12tryorich_djvu.txt G.W. Tryon (1889) Manual of Conchology vol. XII p. 140 (described as ''Addisonia paradoxa'')]</ref>

== Habitat == Minimum recorded depth is 91 m.<ref name="Welch 2010"/> Maximum recorded depth is 1170 m.<ref name="Welch 2010"/>

==References== {{Reflist}} * McLean, J. H. 1985. ''The Archaeogastropod family Addisoniidae Dall 1882'': Life habit and review of species. Veliger 28: 99–108 * Rosenberg, G. 1992. ''Encyclopedia of Seashells''. Dorset: New York. 224 pp. page(s): 31 * Dantart L. & Luque A. A. (1994). ''Cocculiniformia and Lepetidae (Gastropoda: Archaeogastropoda) from Iberian waters''. Journal of Molluscan Studies 60 (3): 277-313 * Turgeon, D.D., et al. 1998. ''Common and scientific names of aquatic invertebrates of the United States and Canada''. American Fisheries Society Special Publication 26-page(s): 59 * Gofas, S.; Le Renard, J.; Bouchet, P. (2001). Mollusca, in: Costello, M.J. et al. (Ed.) (2001). ''European register of marine species: a check-list of the marine species in Europe and a bibliography of guides to their identification''. Collection Patrimoines Naturels, 50: pp.&nbsp;180–213 * Roldan E. & Luque A. (2010) ''The ecology, biology and taxonomy of Addisonia excentrica (Tiberi, 1855) (Cocculiniformia: Addisoniidae) from southern Spain''. Journal of Molluscan Studies 76:201–210

==External links== * [https://europeanjournaloftaxonomy.eu/index.php/ejt/article/view/1605/5667 Serge GOFAS, Ángel A. LUQUE, Joan Daniel OLIVER, José TEMPLADO & Alberto SERRA (2021) - The Mollusca of Galicia Bank (NE Atlantic Ocean); European Journal of Taxonomy 785: 1–114] * {{Gastropods.com|key=6|id=21196|title=''Addisonia excentrica''|access-date=30 January 2011}}

{{Taxonbar|from=Q3171963}}

{{DEFAULTSORT:Addisonia Excentrica}} Category:Addisoniidae Category:Gastropods described in 1855