''Benthofascis atractoides'' is an extinct species of

sea snail Sea snail is a common name for slow-moving marine gastropod molluscs, usually with visible external shells, such as whelk or abalone. They share the taxonomic class Gastropoda with slugs, which are distinguished from snails primarily by the ...

, a marine

gastropod The gastropods (), commonly known as snails and slugs, belong to a large taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, from freshwater, and from land. T ...

mollusk Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85,000 extant species of molluscs are recognized. The number of fossil species is e ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Conorbidae Conorbidae is a monophyletic family of small to medium-sized sea snails, marine gastropod mollusks in the superfamily Conoidea.Tucker J.K. & Tenorio M.J. (2009) Systematic classification of Recent and fossil conoidean gastropods. Hackenheim: ...

Description

The length of an adult shell attains 16.5 mm, its diameter 6.5 mm. It is superficially similar to ''

Benthofascis conorbioides ''Benthofascis conorbioides'' is a species of sea snail, a marine gastropod mollusc in the family Conorbidae.Bouchet, P. (2015). Benthofascis conorbioides Tucker, Tenorio & Stahlschmidt, 2011. In: MolluscaBase (2015). Accessed through: World Reg ...

'', but it does not resorb the inner whorls. (Original description) The biconic, moderately thick shell has an ovately fusiform shape. Its surface is spirally furrowed, smooth and shining. The

spire A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spires are ...

is regularly conical and measures about one-third the total length of the shell. It consists of five

whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). Whorls in nature File:Photograph and axial plane floral ...

s, ending in a small, blunt, turbinate

protoconch A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also called ...

of two and a-half smooth rounded whorls. The whorls of the teleoconch are slightly convex. They are separated by a well-defined linear suture and ornamented by six flat spiral ribs, the three posterior ones separated by flat shallow sulci of about equal width, the three anterior ones by linear grooves sometimes almost obsolete. The interstitial furrows are punctulatedly impressed. The

body whorl The body whorl is part of the morphology of the shell in those gastropod mollusks that possess a coiled shell. The term is also sometimes used in a similar way to describe the shell of a cephalopod mollusk. In gastropods In gastropods, the b ...

is obtusely angled at the periphery, regularly attenuated anteriorly; ornamented with flat spiral ribs (about 30), separated by narrow furrows, crossed by sigmoidal lines of growth which produce the appearance of punctations in the interstitial furrows. The

aperture In optics, an aperture is a hole or an opening through which light travels. More specifically, the aperture and focal length of an optical system determine the cone angle of a bundle of rays that come to a focus in the image plane. An opt ...

is narrow, broadly emarginate in front and measures about half the length of the shell. The outer lip is thin and sharp on the edge, smooth within, much curved medially.Tate, R. (1890) ''The gastropods of the older Tertiary of Australia-part III''. Transactions of the Royal Society of South Australia, 13 p. 200
(described as ''Conus (Conorbis) atractoides'')

Description

Distribution

References

External links