Depressizona

Depressizona is a genus of small to minute sea snails, marine gastropod molluscs or micromolluscs in the superfamily Scissurelloidea.

Depressizona
Scientific classification
Kingdom:	Animalia
Phylum:	Mollusca
Class:	Gastropoda
(unranked):	clade Vetigastropoda
Superfamily:	Scissurelloidea
Family:	Depressizonidae Geiger, 2003[1]
Genus:	Depressizona Geiger, 2003[1]
Type species
Depressizona exorum Geiger, 2003 (type by original designation)
Diversity[2]
2 species

Depressizona is the only genus within the family Depressizonidae.^[2]

Depressizonidae was described as the subfamily Depressizoninae Geiger, 2003, in 2003. Then in 2005 it was considered to be a synonym of Scissurellinae in the family Scissurellidae according to the taxonomy of Bouchet & Roctoi (2005)^[3] and it has also been placed in Scissurellidae.^[4] In 2009 it was updated to the family level, Depressizonidae, when the second known species Depressizona axiosculpta was described.^[2]

Species

Genus Depressizona contains two species only:

• Depressizona axiosculpta Geiger, 2009^[2][5] It was described from only one specimen in poor condition known from Tonga. Geiger (2012) illustrated a second specimen in much better condition.
• Depressizona exorum Geiger, 2003^[6] - from Easter Island. Type species of the genus Depressizona.

Description

The shape of the shell is calyptraeiform.

References

1. Geiger D. L. (2003). "Phylogenetic assessment of characters proposed for the generic classification of Recent Scissurellidae (Gastropoda: Vetigastropoda) with a description of one new genus and six new species from Easter Island and Australia". Molluscan Research 23(1): 21-83. doi:10.1071/MR02017, abstract. PDF.
2. Geiger D. L. (2009). "A new species of Depressizona and the family rank of Depressizonidae". Zootaxa 2059: 57-59. abstract, full article.
3. Bouchet, Philippe; Rocroi, Jean-Pierre; Frýda, Jiri; Hausdorf, Bernard; Ponder, Winston; Valdés, Ángel & Warén, Anders (2005). "Classification and nomenclator of gastropod families". Malacologia. 47 (1–2). Hackenheim, Germany: ConchBooks: 1–397. ISBN 3-925919-72-4. ISSN 0076-2997.
4. Depressizona. Retrieved through: World Register of Marine Species on 11 April 2010.
5. Depressizona axiosculpta Geiger, 2009. Retrieved through: World Register of Marine Species on 11 April 2010.
6. Depressizona exorum Geiger, 2003. Retrieved through: World Register of Marine Species on 11 April 2010.

• Geiger D.L. (2012) Monograph of the little slit shells. Volume 1. Introduction, Scissurellidae. pp. 1-728. Volume 2. Anatomidae, Larocheidae, Depressizonidae, Sutilizonidae, Temnocinclidae. pp. 729–1291. Santa Barbara Museum of Natural History Monographs Number 7.