Extra extra or Marginella extra[2] is a species of minute sea snail, a marine gastropod mollusk or micromollusk in the family Cystiscidae. Some malacologists place this genus more simply in the family Marginellidae.

Extra extra
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Mollusca
Class: Gastropoda
Subclass: Caenogastropoda
Order: Neogastropoda
Family: Cystiscidae
Subfamily: Cystiscinae
Genus: Extra
Species:
E. extra
Binomial name
Extra extra
Synonyms

Taxonomy

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Marginella extra was originally described under name Extra extra by French zoologist Félix Pierre Jousseaume in 1894. He placed this species to the monotypic genus Extra Jousseaume, 1894. Dautzenberg (1929)[3] moved this species into genus Marginella.

Diagnosis

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The shell is minute, white, semitranslucent; prominent axial costae present; spire sunken but not immersed; lip strongly thickened, smooth, lacking denticulation, flared posteriorly; siphonal notch absent; posterior notch absent; distinct parietal callus "shield" present; columella multiplicate, with 5 plications plus parietal lirae, plications slightly excavated inside aperture due to parietal callus deposits.

Distribution and habitat

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Recorded only from western Indian Ocean along Madagascar, apparently in shallow water.

References

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  1. ^ a b Jousseaume, F.P. (1894). "Diagnoses des coquilles de nouveaux mollusques". Bulletin de la Société Philomathique de Paris. 8 (6): 98–105. Retrieved 4 July 2020.
  2. ^ WoRMS (2009). Extra extra (Jousseaume, 1894). Accessed through the World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=217193 on 4 December 2010
  3. ^ Dautzenberg, Ph. (1929). Mollusques testaces marins de Madagascar. Faune des Colonies Françaises, Tome III
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