''Sediliopsis chowanensis'' 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 in the family

Pseudomelatomidae Pseudomelatomidae is a family of predatory sea snails, marine gastropods included in the superfamily Conoidea (previously Conacea) and part of the Neogastropoda ( Bouchet & Rocroi, 2005). In 1995 Kantor elevated the subfamily Pseudomelatomina ...

, the turrids and allies.Julia Gardner (1948) - Mollusca from the Miocene and lower Pliocene of Virginia and North Carolina, Part 2, Scaphopoda and Gastropoda; USGS Professional Paper 199- B

Description

The length of the shell attains 16.5 mm, its diameter 5.5 mm. (Original description) A slender shell of medium size containing about nine

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. The apex is decorticated, but apparently the smooth papillate initial whorl is succeeded by a little more than half a whorl, on which the sculpture is limited to a medial and a stronger anterior spiral. The remaining whorls are both axially and spirally adorned. The aial ribs number 13 on the later whorls. These are narrow, rounded, undulating the whorls from the anal fasciole to the anterior suture. but evanescent on the columella. The spiral sculpture is elaborate. The primaries are low, flat bands about 0.2 millimeter in breadth, somewhat irregularly spaced. There are 4 or 5 on the whorls of the spire, twice as many 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 10 lirations on the columella are narrower and more prominent. Between the primaries 1 or 2 secondaries are similar to the former in general character and separated from them and from each other by linear interspaces. They are lacking on the columella and near the apex. The anal fasciole is concave, sculptured with 5 to 7 crowded lirae, which become most prominent directly in front of the suture. The sinus is deep, rather narrow, and is set a little nearer to the periphery than to the posterior suture. The aperture is narrow, ovate and terminates in a short emarginate

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 ...

Distribution

Fossils of this species were found in Pliocene strata of the

Yorktown Formation The Yorktown Formation is a mapped bedrock unit in the Coastal Plain of Maryland, Virginia, North Carolina and South Carolina. It is overconsolidated and highly fossiliferous. Description The Yorktown is composed largely of overconsolidated san ...

, North Carolina, USA.

References

Don I. Tippett, ''Taxonomic notes on the western Atlantic Turridae (Gastropoda: Conoidea)''; the Nautilus v. 109 (1995-1996)
{{DEFAULTSORT:Sediliopsis Chowanensis chowanensis Gastropods described in 1948