''Turris inconstans'' is an extinct

species In biology, a species is the basic unit of Taxonomy (biology), 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 ...

of sea snail, a marine gastropod

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 es ...

in the

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

Turridae Turridae is a taxonomic family name for a number of predatory sea snails, marine gastropod mollusks in the superfamily Conoidea. MolluscaBase (2018). Turridae H. Adams & A. Adams, 1853 (1838). Accessed through: World Register of Marine Specie ...

, the turrids.

Description

The length of the shell attains 28 mm; the maximum diameter is 6.4 mm. (Original description) The long, fusiform shell contains about 10

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 flo ...

s. The first two whorls are turbinate, smooth. The third to sixth whorls show ten or twelve transverse close-set ribs, which, on the other four whorls, show only on the posterior half of each, being replaced by eight or ten revolving riblets, forming a cancellated

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 ...

near middle, and toward 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 ...

appearing alone. The aperture is narrow with a sinus at angle. The

is long. J. G. Cooper. 1894. Catalogue of Californian fossils. (Parts II, III, IV, and V). California State Mining Bureau Bulletin No. 4 1-65
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Distribution

Fossils of this marine species were found in

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

strata in

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the ...

, USA (age range: 55.8 to 48.6 Ma)

References

* R. E. Dickerson. 1913. Fauna of the Eocene at Marysville Buttes, California. University of California Publications Bulletin of the Department of Geology 7(12):257-298 * R. L. Squires. 2001. Additions to the Eocene megafossil fauna of the Llajas Formation, Simi Valley, southern California. Contributions in Science (Natural History Museum of Los Angeles County) 489:1-40 {{DEFAULTSORT:Turris Inconstans inconstans Gastropods described in 1894