''Raphitoma diozodes'' 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 ...

mollusc 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 esti ...

in the family

Raphitomidae Raphitomidae is a family of small to medium-sized sea snails, marine gastropod mollusks in the superfamily Conoidea.Bouchet P. & Rocroi J.-P. (Ed.) (2005). "Classification and nomenclator of gastropod families". ''Malacologia'' 47(1-2). . 39 ...

Description

The length of the shell reaches 7.5 mm, its diameter 3 mm. (Original description) The small shell has a narrow and slender shape. The rather long spire shows a conical shape. The

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 ...

is polygynous, conoidal, with convex

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 and a pointed apex. The teleoconch contains six whorls. The first one is convex and finely ribbed. The others are biangular, the height of which exceeds half the width. They are separated by linear and wavy sutures, ornated with thick ribs, spaced apart, forming two knots crenellated by the two angles which share the height in three equal spaces. There is only spiral nets on 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 ...

, the two upper regions are smooth. The body whorl measures more than five-eighths of the total length. It is ovally attenuated at the base, on which sinuous ribs extend, crossed by an alternating reticulation, which tightens by winding around the

siphonal canal The siphonal canal is an anatomical feature of the shells of certain groups of sea snails within the clade Neogastropoda. Some sea marine gastropods have a soft tubular anterior extension of the mantle called a siphon through which water is ...

. The aperture is very narrow, with almost parallel edges, truncated by the siphonal canal. The outer lip is straight. The columella is slightly callous and almost straight.Cossmann, Maurice. ''Mollusques éocèniques de la Loire-Inférieure. Vol. 1''. Imp. A. Dugas et cie, 1898
/ref>

Distribution

Fossils of this extinct marine species were found in Eocene strata in Brittany, France

References

* Cossmann M. (1898). ''Mollusques éocéniques de la Loire-Inférieure. Appendice au second fascicule.'' Bulletin de la Société des Sciences Naturelles de l'Ouest de la France. 8: 1-55. {{DEFAULTSORT:Raphitoma diozodes diozodes Gastropods described in 1898