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Heterobranchia
Heterobranchia, the heterobranchs (meaning "different-gilled snails"), is a taxonomic clade of snails and slugs, which includes marine, aquatic, and terrestrial gastropod molluscs. Heterobranchia is one of the main clades of gastropods. Currently Heterobranchia comprises two groups: the opisthobranchs, and the pulmonates. Diversity The two subdivisions of this large clade are quite diverse: * Opisthobranchia are virtually all marine species, some shelled and some not, and comprise about 25 families and 2000 species of the bubble shells, the seaslugs, as well as the sea hares. The internal organs of the opisthobranchs have undergone detorsion (unwinding of the viscera that were twisted during torsion). * The Pulmonata comprises about 20000 species, includes the majority of land snails and slugs, many freshwater snails, and a small number of marine species. The mantle cavity of the Pulmonata is modified into an air-breathing organ. They are also characterized by deto ... [...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 Mya may refer to: Brands and product names * Mya (program), an intelligent personal as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caucasotachea Atrolabiata
''Caucasotachea'' is a genus of medium-sized air-breathing land snails, terrestrial pulmonate gastropod molluscs in the family Helicidae.MolluscaBase eds. (2020). MolluscaBase. Caucasotachea C. R. Boettger, 1909. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=996428 on 2020-08-30 Species The following species are currently classified in the genus: * † ''Caucasotachea andrussovi'' Steklov, 1966 * '' Caucasotachea atrolabiata'' (Krynicki, 1833) * † '' Caucasotachea beringi'' Schütt, 1985 * '' Caucasotachea calligera'' ( Dubois de Montpéreux, 1840) * † '' Caucasotachea candirensis'' Schütt, 1985 * '' Caucasotachea intercedens ( Retowski, 1889) * † '' Caucasotachea kubanica'' Steklov, 1966 * '' Caucasotachea leucoranea'' (Mousson, 1863) * † '' Caucasotachea phrygomysica'' (Oppenheim, 1919) * ''Caucasotachea vindobonensis ''Caucasotachea vindobonensis'' is a species of medium-sized air-breathing la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mathildoidea
Mathildoidea is a superfamily of sea snails, marine gastropod mollusks in the informal group Lower Heterobranchia.MolluscaBase eds. (2021). MolluscaBase. Mathildoidea Dall, 1889. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=411861 on 2021-06-25 Families Families within the superfamily Mathildoidea include: *Family Mathildidae * † Family Ampezzanildidae The Ampezzanildidae is an extinct taxonomic family of sea snails, marine gastropod mollusks in the informal group Lower Heterobranchia Lower Heterobranchia, also known as the Allogastropoda, is a group of rather specialized, highly evolved s ... * † Family Anoptychiidae * † Family Gordenellidae * Family Tofanellidae * † Family Trachoecidae References * Jensen, R. H. (1997). A Checklist and Bibliography of the Marine Molluscs of Bermuda. Unp. , 547 pp * Bouchet P., Rocroi J.P., Hausdorf B., Kaim A., Kano Y., Nützel A., Parkhaev P., Schrödl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Architectonicoidea
Architectonicoidea is a superfamily of sea snails, marine gastropod mollusks in the informal group Lower Heterobranchia.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 This superfamily contains the extant family Architectonicidae Architectonicidae, common name the staircase shells or sundials, are a family of sea snails, marine gastropod mollusks in the informal group "Lower Heterobranchia" (= Allogastropoda) of the clade Heterobranchia. The extinct families † Amph ... and also contains the extinct families Amphitomariidae and Cassianaxidae. References Lower Heterobranchia Taxa named by John Edward Gray {{Heterobranchia-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valvatoidea
Valvatoidea is a superfamily of minute freshwater and marine snails, aquatic gastropod mollusks in the informal group Lower Heterobranchia.MolluscaBase eds. (2020). MolluscaBase. Valvatoidea Gray, 1840. Accessed through: World Register of Marine Species at: http://www.marinespecies.org/aphia.php?p=taxdetails&id=153657 on 2020-09-23 Taxonomy *Family Valvatidae *Family Cornirostridae *Family Hyalogyrinidae * † Family Provalvatidae The Provalvatidae is an extinct taxonomic family of aquatic snails, gastropod mollusc Mollusca is the second-largest phylum of invertebrate animals after the Arthropoda, the members of which are known as molluscs or mollusks (). Around 85, ... References Lower Heterobranchia Taxa named by John Edward Gray {{heterobranchia-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Phylogenetics And Evolution
''Molecular Phylogenetics and Evolution'' is a peer-reviewed scientific journal of evolutionary biology and phylogenetics. The journal is edited by E.A. Zimmer. Indexing The journal is indexed in: * EMBiology *Journal Citation Reports *Scopus Scopus is Elsevier's abstract and citation database launched in 2004. Scopus covers nearly 36,377 titles (22,794 active titles and 13,583 inactive titles) from approximately 11,678 publishers, of which 34,346 are peer-reviewed journals in top-l ... * Web of Science External links * Elsevier academic journals Evolutionary biology journals Phylogenetics Molecular biology Publications established in 1992 Monthly journals {{biology-journal-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Malacologia
''Malacologia'' is a peer-reviewed scientific journal in the field of malacology, the study of mollusks. The journal publishes articles in the fields of molluscan systematics, ecology, population ecology, genetics, molecular genetics, evolution, and phylogenetics. The journal specializes in publishing long papers and monographs. The journal publishes at least one, sometimes two, volumes of about 400 pages per year, which may consist of 1 or 2 issues. According to the ''Journal Citation Reports,'' its 2019 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 ... is 13.5. This ranks ''Malacologia'' 1st out of 145 listed journals in the category "Zoology". The journal started publication in 1962. See also *'' Archiv für Molluskenkunde'' *'' Basteria'' *'' Journal of Concholo ... [...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-Ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hermaphroditic
In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. Many taxonomic groups of animals (mostly invertebrates) do not have separate sexes. In these groups, hermaphroditism is a normal condition, enabling a form of sexual reproduction in which either partner can act as the female or male. For example, the great majority of tunicates, pulmonate molluscs, opisthobranch, earthworms, and slugs are hermaphrodites. Hermaphroditism is also found in some fish species and to a lesser degree in other vertebrates. Most plants are also hermaphrodites. Animal species having different sexes, male and female, are called gonochoric, which is the opposite of hermaphrodite. There are also species where hermaphrodites exist alongside males (called androdioecy) or alongside females (called gynodioecy), or all three exist in the same species (called trioecy); these three systems ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Operculum (gastropod)
The operculum (; ) is a corneous or calcareous anatomical structure like a trapdoor that exists in many (but not all) groups of sea snails and freshwater snails, and also in a few groups of land snails; the structure is found in some marine and freshwater gastropods, and in a minority of terrestrial gastropods, including the families Helicinidae, Cyclophoridae, Aciculidae, Maizaniidae, Pomatiidae, etc. The operculum is attached to the upper surface of the foot and in its most complete state, it serves as a sort of "trapdoor" to close the aperture of the shell when the soft parts of the animal are retracted. The shape of the operculum varies greatly from one family of gastropods to another. It is fairly often circular, or more or less oval in shape. In species where the operculum fits snugly, its outline corresponds exactly to the shape of the aperture of the shell and it serves to seal the entrance of the shell. Many families have opercula that are reduced in size, and which a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Torsion (gastropod)
Torsion is a gastropod synapomorphy which occurs in all gastropods during larval development. Torsion is the rotation of the visceral mass, mantle, and shell 180˚ with respect to the head and foot of the gastropod. This rotation brings the mantle cavity and the anus to an anterior position above the head. In some groups of gastropods (Opisthobranchia) there is a degree of secondary detorsion or rotation towards the original position; this may be only partial detorsion or full detorsion. The torsion or twisting of the visceral mass of larval gastropods is not the same thing as the spiral coiling of the shell, which is also present in many shelled gastropods. Development There are two different developmental stages which cause torsion. The first stage is caused by the development of the asymmetrical velar/foot muscle which has one end attached to the left side of the shell and the other end has fibres attached to the left side of the foot and head. At a certain point in larva ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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