Ivara is a small genus

Genus

In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 of sea snail

Sea snail

Sea snail is a common name for those snails that normally live in saltwater, marine gastropod molluscs....

s, pyramidellid

Pyramidellidae

Pyramidellidae, common name the pyram family, or pyramid shells, is a voluminous taxonomic family of mostly small and minute ectoparasitic sea snails, marine heterobranch gastropod molluscs or micromolluscs....

 gastropod mollusks or micromollusk

Micromollusk

A micromollusk is a descriptive term for a shelled mollusk which is extremely small, even at full adult size. The word is usually, but not exclusively, applied to marine mollusks, although in addition, numerous species of land snails and freshwater mollusks also reach adult size at very small...

s. This genus is currently placed in the tribe

Tribe

A tribe, viewed historically or developmentally, consists of a social group existing before the development of, or outside of, states.Many anthropologists use the term tribal society to refer to societies organized largely on the basis of kinship, especially corporate descent groups .Some theorists...

 Chrysallidini, of the family

Family (biology)

In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...

 Odostomiidae. The Brazilian species have been revised by Pimenta et al. (2009). There are both living and fossil species in this genus.

Shell description

The original description (Dall & Bartsch in Arnold 1903) is short: "Odostomias characterized by the spiral striation and tabulated whorls".

Arnold (1903) gives the following characterization of the type species: "Shell minute, ovate, thin; spire elevated; apex acute; whorls five, convex, shouldered above; surface sculptured by fine, spiral ridges and obsolete transverse ribs, more prominent near top of whorls; suture deeply impressed; body-whorl over half length of shell; shouldered above, evenly convex below; aperture truncated above, evenly rounded below; outer lip thin, extending around and up columella, forming a small columellar plication.Dimensions.- Long. 4 mm.; lat. 1.8 mm.; body whorl 2.6 mm.; aperture 1.5 mm. This delicate little shell is easily recognized by its shouldered whorls and delicate spiral sculpture. Specimens identified by Dr. Dall; but the species omitted from the text prepared by Dall and Bartsch. Rare in lower San Pedro series of Deadman Island. One specimen, which is figured, and is now in the collection of Delos Arnold. Living.-Mexical Coast (Dall). Pleistocene.-San Pedro (Arnold)."

Life habits

Little is known about the biology of the members of this genus. As is true of most members of the Pyramidellidae

Pyramidellidae

Pyramidellidae, common name the pyram family, or pyramid shells, is a voluminous taxonomic family of mostly small and minute ectoparasitic sea snails, marine heterobranch gastropod molluscs or micromolluscs....

 sensu lato, they are ectoparasites.

Species

Species within the genus Ivara include:

• Ivara terricula (Dall & Bartsch in Arnold, 1903) - as Odostomia terricula - type species
• Ivara terryi
  Ivara terryi
  Ivara terryi is a species of sea snail, a marine gastropod mollusk in the family Pyramidellidae, the pyrams and their allies.-External links:*...
  
  (Olsson & McGinty, 1958)
• Ivara dollfusi (Locard, 1886)