''Strictispira acurugata'' is an extinct

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of small

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 ...

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.MolluscaBase (2018). Strictispira acurugata (Dall, 1890) †. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=761632 on 2019-01-27

Description

The length of the shell attains 21.2 mm, its diameter 8 mm. (Original description) The strong shell contains nine or ten

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 beside the smooth

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 ...

. The spiral

sculpture Sculpture is the branch of the visual arts that operates in three dimensions. Sculpture is the three-dimensional art work which is physically presented in the dimensions of height, width and depth. It is one of the plastic arts. Durable sc ...

consists of fine scratches on the fasciole, sharp, usually paired, grooves on the body with wider and alternately broad and narrow rounded interspaces which are subnbdulous in the line of the transverse ribs. These nodulations are higher on the posterior margin of the interstitial bands, so that with 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 ...

pointing vertically the base of the shell looks like a tiled roof on a cupola. There is a moderately elevated round thread in front of the suture and more or less undulated by the ends of the ribs behind it. On the siphonal fasciole there are a few fine threads. The transverse sculpture of (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 ...

fifteen) moderately elevated ribs, beginning and strongest on the shoulder of the whorl and fading away anteriorly near the siphonal canal. On the base they are slightly nodulous between the spiral grooves. The anal fasciole is excavated but slightly undulate behind the ribs and marked by fine incremental lines. The notch is not deep but distinct and U-shaped. The siphonal canal is short and wide. 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 rather narrow, with a moderate callus on the pillar and no lirae on the outer lip.Dall, William Healey. "Contributions to the Tertiary fauna of Florida, with special reference to the Miocene Silexbeds of Tempa and the Pliocene beds of the Caloosahatchie River. Part 2, Streptodont and other gastropods, concluded." Wagner Free Institute of Science of Philadelphia, Transactions 3 (1892): 201-471

Distribution

Fossils of this species were found in

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

strata in

Florida Florida is a state located in the Southeastern region of the United States. Florida is bordered to the west by the Gulf of Mexico, to the northwest by Alabama, to the north by Georgia, to the east by the Bahamas and Atlantic Ocean, and to ...

, USA.

References

External links

Tippett D.L. (2006). ''The genus Strictispira in the western Atlantic (Gastropoda: Conoidea).'' Malacologia. 48(1-2): 43-64.

{{DEFAULTSORT:Strictispira Acurugata acurugata Taxa named by William Healey Dall Gastropods described in 1890