The umbilicate pebblesnail, scientific name Clappia umbilicata, is an extinct species

Species

In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 of a small freshwater snail

Freshwater snail

A freshwater snail is one kind of freshwater mollusc, the other kind being freshwater clams and mussels, i.e. freshwater bivalves. Specifically a freshwater snail is a gastropod that lives in a watery non-marine habitat. The majority of freshwater gastropods have a shell, with very few exceptions....

s that had an operculum

Operculum (gastropod)

The operculum, meaning little lid, is a corneous or calcareous anatomical structure which exists in many groups of sea snails and freshwater snails, and also in a few groups of land snails...

, aquatic

Aquatic animal

An aquatic animal is an animal, either vertebrate or invertebrate, which lives in water for most or all of its life. It may breathe air or extract its oxygen from that dissolved in water through specialised organs called gills, or directly through its skin. Natural environments and the animals that...

 gastropod mollusks in the family Lithoglyphidae

Lithoglyphidae

Lithoglyphidae is a family of small freshwater snails with gills and an operculum, aquatic gastropod mollusks.This family is in the superfamily Rissooidea and in the clade Littorinimorpha .- Taxonomy :Taylor , Ponder & Warén and Kabat & Hershler considered this taxon as a subfamily...

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Distribution

This species was endemic to the Alabama

Alabama

Alabama is a state located in the southeastern region of the United States. It is bordered by Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama ranks 30th in total land area and ranks second in the size of its inland...

, United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. The type locality is Coosa River

Coosa River

The Coosa River is a tributary of the Alabama River in the U.S. states of Alabama and Georgia. The river is about long altogether.The Coosa River is one of Alabama's most developed rivers...

 at Wetumpka, Alabama

Wetumpka, Alabama

Wetumpka is a city in Elmore County, Alabama, United States. At the 2000 census the population was 5,726.The city is the county seat of Elmore County, one of the fastest growing counties in the state....

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Its distribution included: Coosa River at Duncan's Ripple, The Bar and Higgin's Ferry in Chilton County; and Butting Ram Shoals in Coosa County, Alabama

Coosa County, Alabama

Coosa County is a county of the U.S. state of Alabama. Its name derives from a town of the Creek tribe. As of 2010 the population was 11,539, but since that time it has lost the most population by percentage of any Alabama county...

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Description

This species has been discovered and described under the name Somatogyrus umbilicatus by American malacologist Bryant Walker in 1904. Walker's type description reads as follows:

The color of Clappia umbilicata was black. It presumably mean the whole animal including snout

Snout

The snout, or muzzle, is the protruding portion of an animal's face, consisting of its nose, mouth, and jaw.-Terminology:The term "muzzle", used as a noun, can be ambiguous...

, nape, mantle

Mantle (mollusc)

The mantle is a significant part of the anatomy of molluscs: it is the dorsal body wall which covers the visceral mass and usually protrudes in the form of flaps well beyond the visceral mass itself.In many, but by no means all, species of molluscs, the epidermis of the mantle secretes...

 and foot. The black color of the mantle has been verified by Thompson (1984).

Clappia umbilicata has 56-59 rows of teeth on its radula

Radula

The radula is an anatomical structure that is used by molluscs for feeding, sometimes compared rather inaccurately to a tongue. It is a minutely toothed, chitinous ribbon, which is typically used for scraping or cutting food before the food enters the esophagus...

. Each row has 6-7 central basocones, 6-7 central octocones, 18-21 lateral teeth, ca. 50 inner marginal teeth and ca. 35 outer marginal teeth.

Ecology

Its natural habitat

Habitat

* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...

 was river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

s. Clappia umbilicata required rapid flowing sections of river shoals. It died out because of silting of its habitat after the dam

Dam

A dam is a barrier that impounds water or underground streams. Dams generally serve the primary purpose of retaining water, while other structures such as floodgates or levees are used to manage or prevent water flow into specific land regions. Hydropower and pumped-storage hydroelectricity are...

 was constructed (Jordan Dam and Jordan Lake).

Based on examination of radula, Thompson (1984) hypothesized, that Clappia umbilicata was grazing on fine particles of plants and it was specialized on more fine partiecles than the genus Somatogyrus

Somatogyrus

Somatogyrus is a genus of very small freshwater and brackish water snails that have an operculum, aquatic gastropod mollusks in the family Hydrobiidae.-Species:Species within the genus Somatogyrus include:...

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