Extra extra

Extra extra
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
Subclass:	Caenogastropoda
Order:	Neogastropoda
Family:	Cystiscidae
Subfamily:	Cystiscinae
Genus:	Extra
Species:	E. extra
Binomial name
	Extra extra; (Jousseaume, 1894)
Synonyms
	Marginella extra Jousseaume, 1894;

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.

Taxonomy[]

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[]

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[]

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

References[]

^ ^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.
^ 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
^ Dautzenberg, Ph. (1929). Mollusques testaces marins de Madagascar. Faune des Colonies Françaises, Tome III

External links[]

Coovert G. A. & Coovert H. K. (1995). "Revision of the Supraspecific Classification of Marginelliform Gastropods". The Nautilus 109(2 & 3):43–110

[Jousseaume1894-1] 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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