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Skenea Basistriata
''Skenea basistriata'' is a species of sea snail, a marine gastropod mollusk in the family Skeneidae. Description The length of the shell varies between 1.2 mm and 4 mm. The smooth, shining shell is narrowly umbilicated. It contains 4½ tumid whorls with a deep suture. These whorls are rapidly increasing in size. The base of the shell shows an oblique, arcuate stripe running into the umbilicus. (described as ''Cyclostrema basistriata'') Distribution This species occurs in European waters, and the Atlantic Boreal to Arctic region. It also has been found as a fossil in the Italian |
Addison Emery Verrill
Addison Emery Verrill (February 9, 1839 – December 10, 1926) was an American invertebrate zoologist, museum curator and university professor. Life Verrill was born on February 9, 1839 in Greenwood, Maine, the son of George Washington Verrill and Lucy (Hillborn) Verrill. As a boy he showed an early interest in natural history, building collections of rocks and minerals, plants, shells, insects and other animals. When he moved with his family to Norway, Maine at age fourteen he attended secondary school at the Norway Liberal Institute. Verrill started college in 1859 at Harvard University and studied under Louis Agassiz. He graduated in 1862 with a B.A. He went on scientific collecting trips with Alpheus Hyatt and Nathaniel Shaler in the summer of 1860 to Trenton Point, Maine and Mount Desert Island and in the summer of 1861 to Anticosti Island and Labrador. In 1864 Verrill made reports on mining, or prospective mining, properties in New Hampshire, New York, and Pennsylvania. Tw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 absence of a visible shell. Definition Determining whether some gastropods should be called sea snails is not always easy. Some species that live in brackish water (such as certain neritids) can be listed as either freshwater snails or marine snails, and some species that live at or just above the high tide level (for example species in the genus '' Truncatella'') are sometimes considered to be sea snails and sometimes listed as land snails. Anatomy Sea snails are a very large group of animals and a very diverse one. Most snails that live in salt water respire using a gill or gills; a few species, though, have a lung, are intertidal, and are active only at low tide when they can move around in the air. These air-breathing species includ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. There are many thousands of species of sea snails and slugs, as well as freshwater snails, freshwater limpets, and land snails and slugs. The class Gastropoda contains a vast total of named species, second only to the insects in overall number. The fossil history of this class goes back to the Late Cambrian. , 721 families of gastropods are known, of which 245 are extinct and appear only in the fossil record, while 476 are currently extant with or without a fossil record. Gastropoda (previously known as univalves and sometimes spelled "Gasteropoda") are a major part of the phylum Mollusca, and are the most highly diversified class in the phylum, with 65,000 to 80,000 living snail and slug species. The anatomy, behavior, feeding, and re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 estimated between 60,000 and 100,000 additional species. The proportion of undescribed species is very high. Many taxa remain poorly studied. Molluscs are the largest marine phylum, comprising about 23% of all the named marine organisms. Numerous molluscs also live in freshwater and terrestrial habitats. They are highly diverse, not just in size and anatomical structure, but also in behaviour and habitat. The phylum is typically divided into 7 or 8 taxonomic classes, of which two are entirely extinct. Cephalopod molluscs, such as squid, cuttlefish, and octopuses, are among the most neurologically advanced of all invertebrates—and either the giant squid or the colossal squid is the largest known invertebrate species. The gas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skeneidae
The Skeneidae are a speciose family of minute to small marine gastropod molluscs in the superfamily Trochoidea.Bouchet, P.; Gofas, S. (2013). Skeneidae. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=558146 on 2013-09-30 The former subfamily Skeneinae (in the family Turbinidae) was loosely defined. Information on the specific characters of this family are incompletely described. Recent molecular evidence suggests that a number of these genera in Skeneinae probably belong to other families altogether, so many of these assignments must be regarded as provisional. Williams noted in 2012 that "this group is in a desperate need of revision". The subfamily Skeneidae has been upgraded to the status of family Skeneidae, comprising most genera formerly in the subfamily Skeneinae. But even then, the family Skeneidae represents a polyphyletic, “skeneimorph” assemblage. It should be pruned of many genera which would go to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whorl (mollusc)
A whorl is a single, complete 360° revolution or turn in the spiral growth of a mollusc shell. A spiral configuration of the shell is found in numerous gastropods, but it is also found in shelled cephalopods including ''Nautilus'', ''Spirula'' and the large extinct subclass of cephalopods known as the ammonites. A spiral shell can be visualized as consisting of a long conical tube, the growth of which is coiled into an overall helical or planispiral shape, for reasons of both strength and compactness. The number of whorls which exist in an adult shell of a particular species depends on mathematical factors in the geometric growth, as described in D'Arcy Wentworth Thompson's classic 1917 book ''On Growth and Form'', and by David Raup. The main factor is how rapidly the conical tube expands (or flares-out) over time. When the rate of expansion is low, such that each subsequent whorl is not that much wider than the previous one, then the adult shell has numerous whorls. When the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Umbilicus (mollusc)
The umbilicus of a shell is the axially aligned, hollow cone-shaped space within the whorls of a coiled mollusc shell. The term umbilicus is often used in descriptions of gastropod shells, i.e. it is a feature present on the ventral (or under) side of many (but not all) snail shells, including some species of sea snails, land snails, and freshwater snails. The word is also applied to the depressed central area on the planispiral coiled shells of ''Nautilus'' species and fossil ammonites. (These are not gastropods, but shelled cephalopods.) In gastropods The spirally coiled whorls of gastropod shells frequently connect to each other by their inner sides, during the natural course of its formation. This results in a more or less solid central axial pillar, known as the columella. The more intimate the contact between the concave side of the whorls is, the more solid the columella becomes. On the other hand, if this connection is less intense, a hollow space inside the whorls may re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58See the 2014 version of the ICS geologic time scale million years ago. It is the second and most recent epoch of the Neogene Period in the . The Pliocene follows the Epoch and is followed by the Epoch. Prior to the 2009 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skenea
''Skenea'' is a genus of small to minute sea snails, marine gastropod mollusks in the family Skeneidae. This genus is type genus for the family Skeneidae. It has been used as a general receptacle for species that are probably unrelated to the type species ''Helix serpuloides'' Montagu, 1808, such as '' Skenea divae'' Carrozza & Van Aartsen, 2001 and '' Skenea nilarum'' Engl, 1996. Species Species within the genus ''Skenea'' include: * '' Skenea areolata'' (Sars, 1878) * '' Skenea basicarinata'' Hoffman, Gofas & Freiwald, 2020 * '' Skenea basistriata'' (Jeffreys, 1877) * '' Skenea californica'' (Bartsch, 1907) * '' Skenea carmelensis'' Smith & Gordon, 1948 * '' Skenea catenoides'' (Monterosato, 1877) * '' Skenea concordia'' (Bartsch, 1920) * '' Skenea coronadoensis'' (Arnold, 1903) * '' Skenea costulata'' Sbrana & Siracusa, 2018 * † '' Skenea crassa'' Lozouet, 1999 * † '' Skenea dautzenbergi'' (Glibert, 1949) * '' Skenea diaphana'' (A. E. Verrill, 1884) * '' Skenea divae'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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