|
Gemmula Samueli
''Gemmula samueli'' is an extinct species of sea snail, a marine gastropod mollusk in the family Turridae, the turrids. Description Dimensions: length 12 mm; breadth 4 mm; length of the aperture 7 mm. The fusiform shell is elongate. The turbinate protoconch is composed of three smooth whorls, the suture of which is marginate. In the brephic stage the margination is much accentuated, and at a later period of growth gives way to a row of small, distant granules. In the same manner, the median, tuberculated carina of the adult commences in the brephic stage by large obtuse uodulations. The shell is thus described by Mr. Tenison-Woods: "It is a polished shell, with whorls angular in the middle, supporting a single, somewhat distant series of coarse, blunt, somewhat square tubercles. These are exactly on the line of the sinus, and at each side the lines of growth curve away from it. The sinus itself is deep, broad, and somewhat quadrate. The aperture is long and rou ... [...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] |
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 Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=152 on 2018-07-22 The family name Turridae was originally given to a very large group of several thousand sea snail species that were thought to be closely related. The family was described with about 700 genus-group taxa and an estimated 10,000 recent and fossil species. However, that original grouping was discovered to be polyphyletic. In recent years, the family Turridae has been much reduced in size, because a number of other families were created to contain the monophyletic lineages that had previously been thought to belong in the same family. The common name ''turrids'' is still used informally to refer to the polyphyletic group. Distribution Species in the family ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protoconch
A protoconch (meaning first or earliest or original shell) is an embryonic or larval shell which occurs in some classes of molluscs, e.g., the initial chamber of an ammonite or the larval shell of a gastropod. In older texts it is also called "nucleus". The protoconch may sometimes consist of several whorls, but when this is the case, the whorls show no growth lines. The whorls of the adult shell, which are formed after the protoconch, are known as the teleoconch. The teleoconch starts forming when the larval gastropod becomes a juvenile, and the protoconch may dissolve. Quite often there is a visible line of demarcation where the protoconch ends and the teleoconch begins, and there may be a noticeable change in sculpture, or a sudden appearance of sculpture at that point. In some gastropod groups (such as the Architectonicidae), the teleoconch whorls spiral in the opposite direction to the protoconch. In those cases, the shell is called heterostrophic. In species which ha ... [...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] |
Julian Tenison-Woods
Julian Edmund Tenison-Woods (15 November 18327 October 1889), commonly referred to as Father Woods, was an English Catholic priest and geologist who served in Australia.D. H. BorchardtTenison-Woods, Julian Edmund (1832–1889) ''Australian Dictionary of Biography'', Volume 6, MUP, 1976, pp. 254–255. Retrieved 23 March 2010. With Mary MacKillop, he co-founded the Sisters of St Joseph of the Sacred Heart at Penola in 1866. Early life Tenison-Woods was born in London, the sixth son (of eleven children) of James Dominick Woods, A list of corrections by Father Woods' brother a sub-editor of ''The Times'', and his wife, Henrietta Maria Saint-Eloy Tenison, daughter of the Rev. Joseph Tenison, rector of Donoughmore, County Wicklow and of the same family as Archbishop Thomas Tenison. She became a Catholic. Julian Tenison-Woods was baptised by the Rev. John White of the Belgian Chapel, Southwark, and confirmed by Cardinal Wiseman, at that time Vicar-Apostolic of the London District. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clavatula
''Clavatula'' is a genus of sea snails, marine gastropod mollusks in the family Clavatulidae. Description In this genus, the shell is fusiform, with a well-produced spire. The whorls are coronated with tubercles or short spines at the suture;. The aperture is oval. The columellar lip is smooth, arcuate, and callous behind. The outer lip is thin and arcuated, with the anal sinus situated below the sutural coronal. The operculum is semioval with its nucleus about the middle, on the inner side. The foot is large, short and obtuse behind. The eyes are placed externally near the extremity of the tentacles. The radula contains a small unicuspid central tooth with single sharp laterals (formula :1-1-1). The species mostly inhabits the west coast of Africa. Species Species within the genus ''Clavatula'' include: * '' Clavatula ahuiri'' Cossignani & Ardovini, 2014 * †'' Clavatula aralica'' (Luković, 1924) (an extinct species from the Eocene in western Kazakhstan (Tshegan Formatio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 is drawn into the mantle cavity and over the gill and which serves as a chemoreceptor to locate food. Siphonal canals allow for active transport of water to sensory organs inside the shell. Organisms without siphonal canals in their shells rely on passive or diffuse transport or water into their shell. Those with siphonal canals have a direct inhalant stream of water that interacts with sensory organs to detect concentration and direction of a stimulus, such as food or mates. In certain groups of carnivorous snails, where the siphon is particularly long, the structure of the shell has been modified in order to house and protect the soft structure of the siphon. Thus the siphonal canal is a semi-tubular extension of the aperture of the shell th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Surcula
''Turricula'' is a genus of sea snails, marine gastropod mollusks in the family (biology), family Clavatulidae. Taxonomy Clavatulidae was raised, based on cladistic analysis, from subfamily to the family level by Rosenberg in 1998. It remained regarded as a subfamily of Turridae by several malacologists (Kantor, Sysoev).World Register of Marine Species: Clavatulidae accessed 1 April 2010. until a new publication in 2011 Fossil records This genus is known in the fossil records from the Cretaceous to the Quaternary (age range: from 70.6 to 0.0 million years ago). Fossils of species within this genus have been found all over the world.[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Sea Snail")
.jpg "Click for more on -> Siphonal Canal")
