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Seguenzia Monocingulata
''Seguenzia monocingulata'' is an extinct species of sea snail, a marine gastropod mollusk in the family Seguenziidae. It resembles '' Seguenzia formosa'' and has been regarded as a synonym of that (extant) species. However the two species are distinct, based on shell morphology. Description The height of the shell attains 4 mm. The white, imperforate shell has a high conoid shape. The whorls have revolving ribs, of which the last has about four distant prominent ones, besides minor striae on the base. Distribution This species was originally described by Seguenza from Pliocene fossils found at Torrente Trapani Trapani ( , ; scn, Tràpani ; lat, Drepanum; grc, Δρέπανον) is a city and municipality (''comune'') on the west coast of Sicily, in Italy. It is the capital of the Province of Trapani. Founded by Elymians, the city is still an impor ..., a locality of the city of Messina, Sicily. It is common in deep-sea deposits from southern Italy. References ... [...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] |
Seguenziidae
Seguenziidae is a family of very small deepwater sea snails, marine gastropod mollusks in the superfamily Seguenzioidea (according to the taxonomy of the Gastropoda by Bouchet & Rocroi, 2005).Bouchet, P. (2012). Seguenziidae. Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=23116 on 2013-03-26 Distribution Species from this family occur in the Atlantic Ocean, the Pacific Ocean, the Indian Ocean and the Antarctic Ocean, mostly at bathyal and abyssal depths. Only a few species have been found at depths less than 300 m and none at intertidal depths. Description The thin, translucent, white shell has a trochiform shape. They are small or very small. Their maximum height is 22 mm. They are usually nacreous. The inner lip has often a tooth-like fold. The outer lip has characteristically one to three concave notches (except in the genus '' Guttula''). The chitinous operculum is multispiral. The rhipidoglossan radula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seguenzia Formosa
''Seguenzia formosa'' is a species of extremely small deep water sea snail, a marine gastropod mollusk in the family Seguenziidae.Intergovernmental Oceanographic Commission (IOC) of UNESCO. The Ocean Biogeographic Information System (OBIS) The epithet "formosa" means "beautiful". It resembles ''Seguenzia monocingulata'' and has been regarded as a synonym of that (extinct) species. However the two species are distinct, based on shell morphology. Description (Original description by J.G. Jeffreys) The rather thin, semitransparent, nacreous and glossy shell has a globosely conical shape. The sculpture of the shell shows sharp keel-like spiral ribs or ridges, of which there are two on the middle of the body whorl (besides ten thread-like riblets on the base) and one on the middle of each of the other whorls. There is also a slighter rib immediately below the suture. Between the ribs the surface is covered with numerous and delicate curved striae, which turn alternately in differ ... [...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] |
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] |
Trapani
Trapani ( , ; scn, Tràpani ; lat, Drepanum; grc, Δρέπανον) is a city and municipality (''comune'') on the west coast of Sicily, in Italy. It is the capital of the Province of Trapani. Founded by Elymians, the city is still an important fishing port and the main gateway to the nearby Egadi Islands. History Drepana was founded by the Elymians to serve as the port of the nearby city of Eryx (present-day Erice), which overlooks it from Monte Erice. The city sits on a low-lying promontory jutting out into the Mediterranean Sea. It was originally named ''Drépanon'' from the Greek word for "sickle", because of the curving shape of its harbour. Carthage seized control of the city in 260BC, subsequently making it an important naval base, but ceded it to Rome in 241BC following the Battle of the Aegates in the First Punic War. Two ancient legends relate supposed mythical origins for the city. In the first legend, Trapani stemmed from the sickle which fell from the hands o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sicily
(man) it, Siciliana (woman) , population_note = , population_blank1_title = , population_blank1 = , demographics_type1 = Ethnicity , demographics1_footnotes = , demographics1_title1 = Sicilian , demographics1_info1 = 98% , demographics1_title2 = , demographics1_info2 = , demographics1_title3 = , demographics1_info3 = , timezone1 = CET , utc_offset1 = +1 , timezone1_DST = CEST , utc_offset1_DST = +2 , postal_code_type = , postal_code = , area_code_type = ISO 3166 code , area_code = IT-82 , blank_name_sec1 = GDP (nominal) , blank_info_sec1 = €89.2 billion (2018) , blank1_name_sec1 = GDP per capita , blank1_info_sec1 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seguenzia
''Seguenzia'' is a genus of sea snails, marine gastropod mollusks in the family Seguenziidae. This genus was named after Giuseppe Seguenza (1833-1889), the palaeontologist at Messina, Italy. Description The thin shell has a turbinate or subtrochoid shape. It is translucent, the outer layer very slight, somewhat nacreous in fresh specimens. There is no epidermis. The shell contains spiral carinations. The upper part of the body whorl is deeply and widely grooved. The aperture is irregular and sinuous behind. The columella is twisted and abruptly notched below. It has a small tooth-like process. The base of the shell shows a sinus. It is deeply umbilicated or imperforate. The thin operculum is oval, with a subcentral nucleus and with obsolete, numerous concentric lines. Species According to the World Register of Marine Species (WoRMS), the following species with valid name are included within the genus ''Seguenzia'' : *'' Seguenzia antarctica'' Thiele, 1925 *'' Seguenzia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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