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Heterobranch
Heterobranchia, the ''heterobranchs'' (meaning "different-gilled snails"), is a taxonomic clade of snails and slugs, which includes marine, aquatic and terrestrial gastropod mollusks. Heterobranchia is one of the main clades of gastropods. Currently Heterobranchia comprises three informal groups: the lower heterobranchs, the opisthobranchs and the pulmonates.Bouchet P. & Rocroi J.-P. (Ed.); Frýda J., Hausdorf B., Ponder W., Valdes A. & Warén A. 2005. ''Classification and nomenclator of gastropod families''. Malacologia: International Journal of Malacology, 47(1-2). ConchBooks: Hackenheim, Germany. . . 397 pp. http://www.vliz.be/Vmdcdata/imis2/ref.php?refid=78278 Diversity The three subdivisions of this large clade are quite diverse: * The Lower Heterobranchia includes shelled marine and freshwater species. * Opisthobranchia are almost all marine species, some shelled and some not. The internal organs of the opisthobranchs have undergone detorsion (unwinding of the viscer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterobranchia Tree
Heterobranchia, the ''heterobranchs'' (meaning "different-gilled snails"), is a taxonomic clade of snails and slugs, which includes marine, aquatic and terrestrial gastropod mollusks. Heterobranchia is one of the main clades of gastropods. Currently Heterobranchia comprises three informal groups: the lower heterobranchs, the opisthobranchs and the pulmonates.Bouchet P. & Rocroi J.-P. (Ed.); Frýda J., Hausdorf B., Ponder W., Valdes A. & Warén A. 2005. ''Classification and nomenclator of gastropod families''. Malacologia: International Journal of Malacology, 47(1-2). ConchBooks: Hackenheim, Germany. . . 397 pp. http://www.vliz.be/Vmdcdata/imis2/ref.php?refid=78278 Diversity The three subdivisions of this large clade are quite diverse: * The Lower Heterobranchia includes shelled marine and freshwater species. * Opisthobranchia are almost all marine species, some shelled and some not. The internal organs of the opisthobranchs have undergone detorsion (unwinding of the vis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emsian
The Emsian is one of three faunal stages in the Early Devonian Epoch. It lasted from 407.6 ± 2.6 million years ago to 393.3 ± 1.2 million years ago. It was preceded by the Pragian Stage and followed by the Eifelian Stage. It is named after the Ems river in Germany. The GSSP is located in the Zinzil'ban Gorge in the Kitab State Geological Reserve of Uzbekistan, above the contact with the Madmon Formation. In North America the Emsian Stage is represented by Sawkill or Sawkillian time. Biological events During this period, earliest known agoniatitid ammonoid fossils began appearing within this stage after first appearing in previous stage and began to evolutionarily radiate within this stage, in which a new ammonoid order Goniatitida rises in the end of Zlichovian stage (Siberian representation; corresponds to early Eifelian and after the end of Early Devonian, before 391.9 mya). Later agoniatitid ammonoids would die out in the Taghanic event in the upper middle Givetian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastropod Shell
The gastropod shell is part of the body of a Gastropoda, gastropod or snail, a kind of mollusc. The shell is an exoskeleton, which protects from predators, mechanical damage, and dehydration, but also serves for muscle attachment and calcium storage. Some gastropods appear shell-less (slugs) but may have a remnant within the mantle, or in some cases the shell is reduced such that the body cannot be retracted within it (semi-slug). Some snails also possess an operculum that seals the opening of the shell, known as the Aperture (mollusc), aperture, which provides further protection. The study of mollusc shells is known as conchology. The biological study of gastropods, and other molluscs in general, is malacology. Shell morphology terms vary by species group. Shell layers The gastropod shell has three major layers secreted by the Mantle (mollusc), mantle. The calcareous central layer, tracum, is typically made of calcium carbonate precipitated into an organic matrix known as c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
BMC Evolutionary Biology
''BMC Ecology and Evolution'' (since January 2021), previously ''BMC Evolutionary Biology'' (2001–2020), is a peer-reviewed open access scientific journal covering all fields of evolutionary biology, including phylogenetics and palaeontology. It was established in 2001 and is part of a series of BMC journals published by BioMed Central. Abstracting and indexing The journal is abstracted and indexed in: According to the ''Journal Citation Reports'', the journal has a 2020 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as i ... of 3.260. References External links * BioMed Central academic journals Creative Commons Attribution-licensed journals {{biology-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxonomy Of The Gastropoda (Bouchet & Rocroi, 2005)
The taxonomy of the Gastropoda as it was revised in 2005 by Philippe Bouchet and Jean-Pierre Rocroi is a system for the scientific classification of gastropod mollusks. (Gastropods are a taxonomic class of animals which consists of snails and slugs of every kind, from the land, from freshwater, and from saltwater.) The paper setting out this taxonomy was published in the journal ''Malacologia''. The system encompasses both living and extinct groups, as well as some fossils whose classification as gastropods is uncertain. The Bouchet & Rocroi system was the first complete gastropod taxonomy that primarily employed the concept of clades, and was derived from research on molecular phylogenetics; in this context a clade is a "natural grouping" of organisms based upon a statistical cluster analysis. In contrast, most of the previous overall taxonomic schemes for gastropods relied on morphological features to classify these animals, and used taxon ranks such as order, superorder ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxonomy Of The Gastropoda (Ponder & Lindberg, 1997)
The taxonomy of the Gastropoda, as revised by Winston Ponder and David R. Lindberg in 1997, is an older taxonomy of the class Gastropoda, the class of molluscs consisting of all snails and slugs. The full name of the work in which this taxonomy was published is ''Towards a phylogeny of gastropod molluscs: an analysis using morphological characters.'' This taxonomy assigns the various Gastropods into ranked categories, such as sub-orders and families, but does not address the classification of genera or individual species. This classification scheme is based on the molluscs' internal and external shapes and forms, but did not take into account any analysis of their DNA or RNA. The classification below was the most recent until Bouchet and Rocroi published their revised taxonomy in 2005, which differs primarily in that the higher taxa are expressed as unranked clades where known, and termed "informal groups" or groups" where monophyly (a single lineage) has not yet been determine ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Winston Ponder
Winston Frank Ponder (born 1941) is a noted malacologist born and educated in New Zealand who has named and described many marine and freshwater animals, especially micromolluscs. Education and career Ponder graduated with an MSc, PhD (1968) and DSc from the University of Auckland, New Zealand. He completed his Ph.D while working at the Dominion Museum but by 1969 he had taken a position at the Australian Museum, where he has remained. Ponder was the principal research scientist in the malacology section of the Australian Museum, Sydney, Australia and helped to build up the museum's mollusc collection so that it became one of the most extensive of its kind in the world. Ponder retired from this post after a long career of more than forty years of research on molluscs, and is now an Honorary Fellow of the museum. He has been the president of the Society of Australian Systematic Biologists, and was the managing editor of the journal ''Molluscan Research'' of the Malacological ... [...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] |
Architectonicidae
Architectonicidae, common name the staircase shells or sundials, are a family (biology), family of sea snails, marine (ocean), marine gastropod mollusks in the informal group "Lower Heterobranchia" (= Allogastropoda) of the clade Heterobranchia. The extinct families † Amphitomariidae Bandel, 1994 and † Cassianaxidae Bandel, 1996 belong to the same superfamily. Genera Genera within the family Architectonicidae include: * ''Adelphotectonica'' Bieler, 1987 * ''Aguayodiscus'' Jaume & Borro, 1946 * ''Architectonica'' Peter Friedrich Röding, Röding, 1798 – type genus * ''Awarua (gastropod), Awarua'' Mestayer, 1930Mestayer (1930). ''Trans. New Zealand Inst.'' 61: 145. * ''Basisulcata'' Melone & Taviani, 1985 * †''Calodisculus'' Rehder, 1935 * †''Climacopoma'' Fischer, 1885 * †''Dinaxis'' Dall in Aldrich, 1895 * †''Discotectonica'' Marwick, 1931 * †''Disculus'' Deshayes, 1863 * †''Eosolarium'' Chavan, 1947 * †''Ewekorolaxis'' Adegoke, 1977 * ''Grandeliacus'' Ired ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterostropha
Heterostropha was a previously used taxonomic category, an order of sea snails, within the superorder Heterobranchia. In the most current gastropod taxonomy, that of Bouchet & Rocroi, this taxon is no longer in use. The molluscs that were placed in this order have a heterostrophic protoconch. This is where the whorls at the very peak of the spire of the shell are coiled in an opposite direction to the adult whorls. The families in this order were sometimes previously classified as opisthobranch Opisthobranchs () is now an informal name for a large and diverse group of specialized complex gastropods which used to be united in the subclass Opisthobranchia. That taxon is no longer considered to represent a monophyletic grouping. Euopisth ...s. References * Paul Martin Chambers. Channel Island Marine Molluscs. Charonia Media, 2008. {{Taxonbar, from=Q1138502 Obsolete gastropod taxa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Edward Gray
John Edward Gray, FRS (12 February 1800 – 7 March 1875) was a British zoologist. He was the elder brother of zoologist George Robert Gray and son of the pharmacologist and botanist Samuel Frederick Gray (1766–1828). The same is used for a zoological name. Gray was keeper of zoology at the British Museum in London from 1840 until Christmas 1874, before the natural history holdings were split off to the Natural History Museum. He published several catalogues of the museum collections that included comprehensive discussions of animal groups and descriptions of new species. He improved the zoological collections to make them amongst the best in the world. Biography Gray was born in Walsall, but his family soon moved to London, where Gray studied medicine. He assisted his father in writing ''The Natural Arrangement of British Plants'' (1821). After being blackballed by the Linnean Society of London, Gray shifted his interest from botany to zoology. He began his zoologica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Berthella Martensi (Pilsbry, 1896)
''Berthella martensi'' is a species of sea slug, a marine gastropod mollusk in the family Pleurobranchidae. Description This species can grow up to a length of . The background coloration of the body varies a great deal, from light orange-brown to black or whitish to cream in color. The body is always marked with dark or clear spots, according to what is the dominant background color. The mantle, which covers the body, is composed of four distinct parts: dorsal, anterior, and two lateral pieces protecting the gills. These lateral pieces are on the right side of the body; they have the same coloration as the body, but are outlined in black. Three of its dorsal parts can be shed in case of danger, a form of autotomy. This species has another means of defense by secreting a repellent acid fluid. The head has a pair of smooth and slightly folded rhinophores. A trapezoid veil masks partially the oral cavity. The egg ribbon is whitish. Image:Berthella martensi.jpg Image:32-East ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
