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
fossil
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...
freshwater snail
Freshwater snails are gastropod mollusks which live in fresh water. There are many different families. They are found throughout the world in various habitats, ranging from ephemeral pools to the largest lakes, and from small seeps and springs ...
with a
gill
A gill () is a respiratory organ that many aquatic organisms use to extract dissolved oxygen from water and to excrete carbon dioxide. The gills of some species, such as hermit crabs, have adapted to allow respiration on land provided they are ...
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
Valvatidae
''Valvatidae'', the valve snails, is a taxonomic family of very small freshwater snails with an operculum, aquatic gastropod mollusks.
Taxonomy
The family Valvatidae has no subfamilies (according to the taxonomy of the Gastropoda by Bouche ...
, the valve snails.
Taylor
Taylor, Taylors or Taylor's may refer to:
People
* Taylor (surname)
**List of people with surname Taylor
* Taylor (given name), including Tayla and Taylah
* Taylor sept, a branch of Scottish clan Cameron
* Justice Taylor (disambiguation)
Plac ...
(1966) stated that ''Valvata oregonensis'' is a
synonym
A synonym is a word, morpheme, or phrase that means exactly or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are all ...
Warner Lakes
The Warner Lakes are a chain of shallow lakes and marshes in the Warner Valley of eastern Lake County, Oregon, United States. The lakes extend the length of the valley, covering approximately .
The lakes are named in honor of Captain William H ...
beds in
eastern Oregon
Eastern Oregon is the eastern part of the U.S. state of Oregon. It is not an officially recognized geographic entity; thus, the boundaries of the region vary according to context. It is sometimes understood to include only the eight easternmost ...
. The age is
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58
''Valvata oregonensis'' was a very common species in eastern Oregon during the
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 ...
. The
University of Oregon
The University of Oregon (UO, U of O or Oregon) is a public research university in Eugene, Oregon. Founded in 1876, the institution is well known for its strong ties to the sports apparel and marketing firm Nike, Inc, and its co-founder, billion ...
collection contains specimens from numerous localities around the Warner Lakes beds,
Snake River Valley
The Snake River cutting through the plain leaves many canyons and Canyon#List of gorges">gorges, such as this one near Twin Falls, Idaho
The Snake River Plain is a geologic feature located primarily within the U.S. state of Idaho. It stret ...
shell
Shell may refer to:
Architecture and design
* Shell (structure), a thin structure
** Concrete shell, a thin shell of concrete, usually with no interior columns or exterior buttresses
** Thin-shell structure
Science Biology
* Seashell, a hard ou ...
is composed of four
whorls
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 d ...
, marked with none to three spiral carinae. The
spire
A spire is a tall, slender, pointed structure on top of a roof of a building or tower, especially at the summit of church steeples. A spire may have a square, circular, or polygonal plan, with a roughly conical or pyramidal shape. Spires are ...
is normally low and umbilicus is wide, exposing all the whorls to the
apex
The apex is the highest point of something. The word may also refer to:
Arts and media Fictional entities
* Apex (comics), a teenaged super villainess in the Marvel Universe
* Ape-X, a super-intelligent ape in the Squadron Supreme universe
*Apex ...
. There is great variation in the height of the spire and with its increase there is a proportionate decrease in the width of the umbilicus. The apical two whorls are flat and planulate, smooth and shining, unmarked with carinae even when the remainder of the shell may have three.
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 ...
is comparatively uniform in character, being composed of fine growth lines.
This species is characterized by its flat nuclear whorls and generally flat shell. Only rarely is the spire as elevated, while great numbers are as flat as the lowest. The thickness of the shells is greater than in any other ''Valvata'' species.
Dimensions of the holotype and paratypes are as follows: The width of the shell is 4.6-8.0 mm. The height of the shell is 2.6-5.4 mm. In general the width of shell can reach up to 10 mm and so this is the largest species of North American ''Valvata''.