''Turris septemlirata'' is an extinct

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

sea snail Sea snails are slow-moving marine (ocean), marine gastropod Mollusca, molluscs, usually with visible external shells, such as whelk or abalone. They share the Taxonomic classification, taxonomic class Gastropoda with slugs, which are distinguishe ...

, a marine

gastropod Gastropods (), commonly known as slugs and snails, belong to a large Taxonomy (biology), taxonomic class of invertebrates within the phylum Mollusca called Gastropoda (). This class comprises snails and slugs from saltwater, freshwater, and fro ...

mollusk Mollusca is a phylum of protostomic invertebrate animals, whose members are known as molluscs or mollusks (). Around 76,000 extant species of molluscs are recognized, making it the second-largest animal phylum after Arthropoda. The ...

in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Turridae Turridae is a Taxonomy (biology), taxonomic family (biology), family name for a number of predatory sea snails, Marine (ocean), marine gastropod mollusks in the superfamily Conoidea.MolluscaBase (2018). Turridae H. Adams & A. Adams, 1853 (1838). ...

, the turrids.

Description

The length of the shell varies between 50 mm and 60 mm. (Original description) The large shell is fusiform and tumid. 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 small, smooth, devoid of ornament, terminating abruptly at its junction with the shell in the brephic stage. The shell contains eleven

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). In nature File:Photograph and axial plane floral diagra ...

s. The suture is canaliculate and bimarginate, rugosely spirally lirate. There are seven principal spirally striated lirae on the penultimate whorl in the adult, but at younger stages of growth they are fewer in number, decreasing gradually to four. The

body whorl The body whorl is part of the morphology (biology), morphology of the gastropod shell, 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 ...

is irregularly Urate throughout. Between the large compound liration on the margin of the suture anteriorly, and the elevated ridge denoting the position of the sinus, is a broad, deep sulcation, which, like the sulci between the lirae, is finely spirally striated and interrupted by lines of growth. The

aperture In optics, the aperture of an optical system (including a system consisting of a single lens) is the hole or opening that primarily limits light propagated through the system. More specifically, the entrance pupil as the front side image o ...

is large, broad, ovate and contracted anteriorly. The outer

lip The lips are a horizontal pair of soft appendages attached to the jaws and are the most visible part of the mouth of many animals, including humans. Mammal lips are soft, movable and serve to facilitate the ingestion of food (e.g. sucklin ...

is thin, sulcate within, crenulated or serrated, arcuate . The sinus is broad and deep and is situated distantly from the suture. The columellar margin is smooth, curved, slightly callous in senile individuals. 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 i ...

is very short and broad. Harris (1897), Catalogue of Tertiary Mollusca in the Department of Geology, British Museum (Natural History) part I p. 39 pl. 2 10 a-d
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Distribution

Fossils of this marine species were found in

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

strata in

Victoria Victoria most commonly refers to: * Queen Victoria (1819–1901), Queen of the United Kingdom and Empress of India * Victoria (state), a state of Australia * Victoria, British Columbia, Canada, a provincial capital * Victoria, Seychelles, the capi ...

, Australia.

References

* Tate (1898), Proceedings of the Royal Society of New South Wales 31 p. 392 * Powell A.W.B. (1944), Rec. Auck. Inst. Mus. 3 (1) p. 8

External links

A.W.B. Powell, The family Turridae in the Indo-Pacific. Part 1. The subfamily Turrinae
{{DEFAULTSORT:Turris septemlirata septemlirata Gastropods described in 1897 Extinct gastropods