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Caspiomyzon Graecus
''Caspiomyzon'' is a genus of lamprey in the family Petromyzontidae. They are native to Eastern Europe and parts of Western and Central Asia. Two of the three species in the genus are endemic to Greece. Taxonomy Species There are currently three recognized species in this genus: * '' Caspiomyzon graecus'' (Renaud & Economidis, 2010) (validity doubtful, may be junior synonym of ''C. hellenicus'') * '' Caspiomyzon hellenicus'' ( Vladykov, Renaud, Kott & Economidis), 1982 (Greek brook lamprey) * '' Caspiomyzon wagneri'' ( Kessler, 1870) (Caspian lamprey) This was formerly considered a monotypic genus containing only ''C. wagneri'', but phylogenetic studies suggest that ''hellenicus'' and ''graecus'', formerly placed in ''Eudontomyzon'', also belong to this genus. Evolution Phylogenetic studies indicate that they are the most basal members of the family Petromyzontidae, and their lineage diverged from the other genera in the family (''Petromyzon'' and ''Ichthyomyzon'') i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lev Berg
Lev Semyonovich Berg, also known as Leo S. Berg (; 14 March 1876 – 24 December 1950) was a leading Russian geographer, biologist and ichthyologist who served as President of the Soviet Geographical Society between 1940 and 1950. He is known for his own evolutionary theory, nomogenesis (a form of orthogenesis incorporating mutationism) as opposed to the theories of Darwin and Lamarck. Life Lev Berg was born in Bessarabia in a Jewish family, the son of Simon Gregoryevich Berg, a notary, and Klara Lvovna Bernstein-Kogan. He graduated from the Second Kishinev Gymnasium in 1894. Like some of his relatives, Berg converted to Christianity in order to pursue his studies at Moscow State University. At Moscow University, Berg studied hydrobiology and geography. He later studied ichthyology and in 1928 was awarded he was also a member of the Russian Academy of Sciences. Lev Berg graduated from the Moscow State University in 1898. Between 1903 and 1914, he worked in the Museum of Z ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vadim Dimitrievitch Vladykov
Vadim (Cyrillic: Вадим) is a Slavic masculine given name derived from the Ruthenian word ''vaditi'' (), meaning ''to blame'' or as a diminutive of Vadimir. ''Dictionary of Russian Names''. : Vadym; : Vadzim. Notable people with the name include: Mononymic *[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58See the 2014 version of the ICS geologic time scale million years ago (Ma). It is the second and most recent epoch of the Neogene Period in the Cenozoic, Cenozoic Era. The Pliocene follows the Miocene Epoch and is followed by the Pleistocene Epoch. Prior to the 2009 revision of the geologic time scale, which placed the four most recent major glaciations entirely within the Pleistocene, the Pliocene also included the Gelasian Stage, which lasted from 2.59 to 1.81 Ma, and is now included in the Pleistocene. As with other older geologic periods, the Stratum, geological strata that define the start and end are well-identified but the exact dates of the start a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes from the Ancient Greek (''Ēṓs'', 'Eos, Dawn') and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch.See: *Letter from William Whewell to Charles Lyell dated 31 January 1831 in: * From p. 55: "The period next antecedent we shall call Eocene, from ήως, aurora, and χαινος, recens, because the extremely small proportion of living species contained in these strata, indicates what may be considered the first commencement, or ''dawn'', of the existing state of the animate creation." The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isoto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Cretaceous
The Late Cretaceous (100.5–66 Ma) is the more recent of two epochs into which the Cretaceous Period is divided in the geologic time scale. Rock strata from this epoch form the Upper Cretaceous Series. The Cretaceous is named after ''creta'', the Latin word for the white limestone known as chalk. The chalk of northern France and the white cliffs of south-eastern England date from the Cretaceous Period. Climate During the Late Cretaceous, the climate was warmer than present, although throughout the period a cooling trend is evident. The tropics became restricted to equatorial regions and northern latitudes experienced markedly more seasonal climatic conditions. Geography Due to plate tectonics, the Americas were gradually moving westward, causing the Atlantic Ocean to expand. The Western Interior Seaway divided North America into eastern and western halves; Appalachia and Laramidia. India maintained a northward course towards Asia. In the Southern Hemisphere, Aus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ichthyomyzon
''Ichthyomyzon'' is a genus of lampreys in the family Petromyzontidae, native to North America. Species There are currently six recognized species in this genus: * '' Ichthyomyzon bdellium'' ( D. S. Jordan, 1885) (Ohio lamprey) * '' Ichthyomyzon castaneus'' Girard, 1858 (Chestnut lamprey) * '' Ichthyomyzon fossor'' Reighard & Cummins Cummins Inc. is an American multinational corporation, multinational corporation that designs, manufactures, and distributes engines, electric vehicle components, and power generation products. Cummins also services engines and related equipmen ..., 1916 (Northern brook lamprey) * '' Ichthyomyzon gagei'' C. L. Hubbs & Trautman, 1937 (Southern brook lamprey) * '' Ichthyomyzon greeleyi'' C. L. Hubbs & Trautman, 1937 (Mountain brook lamprey) * '' Ichthyomyzon unicuspis'' C. L. Hubbs & Trautman, 1937 (Silver lamprey) References Petromyzontidae Jawless fish genera {{jawless-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petromyzon
The sea lamprey (''Petromyzon marinus'') is a parasitic lamprey native to the Northern Hemisphere. It is sometimes referred to as the "vampire fish". It was likely introduced to the Great Lakes region through the Erie Canal in 1825 and the Welland Canal in 1919 where it has attacked native fish such as lake trout, lake whitefish, chub, and lake herring. Sea lampreys are considered a pest in the Great Lakes region as each individual has the potential of killing 40 pounds of fish through its 12–18 month feeding period. Description The sea lamprey has an eel-like body without paired fins. Its mouth is jawless, round and sucker-like, and as wide or wider than the head; sharp teeth are arranged in many concentric circular rows around a sharp, rasp-like tongue. There are seven branchial or gill-like openings behind the eye. Sea lampreys are olive or brown-yellow on the dorsal and lateral part of the body, with some black marblings, with lighter coloration on the belly. Within th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family (, : ) 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". The delineation of what constitutes a family—or whether a described family should be acknowledged—is established and decided upon by active taxonomists. There are not strict regulations for outlining or acknowledging a family, yet in the realm of plants, these classifications often rely on both the vegetative and reproductive characteristics of plant species. Taxonomists frequently hold varying perspectives on these descriptions, leading to a lack of widespread consensus within the scientific community ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Basal (phylogenetics)
In phylogenetics, basal is the direction of the ''base'' (or root) of a phylogenetic tree#Rooted tree, rooted phylogenetic tree or cladogram. The term may be more strictly applied only to nodes adjacent to the root, or more loosely applied to nodes regarded as being close to the root. Note that extant taxa that lie on branches connecting directly to the root are not more closely related to the root than any other extant taxa. While there must always be two or more equally "basal" clades sprouting from the root of every cladogram, those clades may differ widely in taxonomic rank, Phylogenetic diversity, species diversity, or both. If ''C'' is a basal clade within ''D'' that has the lowest rank of all basal clades within ''D'', ''C'' may be described as ''the'' basal taxon of that rank within ''D''. The concept of a 'key innovation' implies some degree of correlation between evolutionary innovation and cladogenesis, diversification. However, such a correlation does not make a given ca ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eudontomyzon
''Eudontomyzon'' is a genus of lamprey in the family Petromyzontidae. Most species are found in Eastern Europe. Species There are currently five recognized species in this genus: * '' Eudontomyzon danfordi'' Regan, 1911 (Carpathian lamprey) * '' Eudontomyzon mariae'' ( L. S. Berg, 1931) (Ukrainian brook lamprey) * '' Eudontomyzon morii'' L. S. Berg, 1931 (Korean lamprey) * '' Eudontomyzon stankokaramani'' M. S. Karaman ( sr), 1974 (Drin brook lamprey) * '' Eudontomyzon vladykovi'' Oliva Oliva (, ; ) is a Municipalities of Spain, municipality in the Comarques of the Valencian Community, ''comarca'' of Safor in the Valencia (autonomous community), Valencian Community, Spain. To its east lie of coastline and beaches fronting t ... & Zanandrea, 1959 (Danubian brook lamprey) A sixth possible undescribed species, the Ukrainian migratory lamprey, ''Eudontomyzon sp. nov. 'migratory, became extinct in the late 19th century. References Jawless fish genera Taxa name ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypic Taxon
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of Genus, genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described. Theoretical implications Monotypic taxa present several important theoretical challenges in biological classification. One key issue is known as "Gregg's Paradox": if a single species is the only member of multiple hierarchical levels (for example, being the only species in its genus, which is the only genus in its family), then each level needs a distinct definition to maintain logical structure. Otherwise, the different taxonomic ranks become effectively identical, which creates problems for organizing biological diversity in a hierarchical o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karl Fedorovich Kessler
Karl Fedorovich Kessler (; – ) was a Baltic German zoologist who worked as a professor of biology at Saint Petersburg Imperial University. Among his contributions was the idea that evolution at an infraspecific level involved mutual aid and that Charles Darwin had placed too much emphasis on competition which he accepted as occurring at the interspecies level. Life and work Kessler was born in Damrau, Königsberg, Konigsberg, where his father was a royal forester (''oberforestmeister''). His father moved to Novgorod Governorate, where Kessler grew up. In 1828, he joined the with a scholarship and went to Saint Petersburg Imperial University in 1834. He attended the zoology lectures of Stepan Kutorga. After graduation he worked as a school mathematics teacher. In 1837, Kessler and his botanist friend from student days, went on an expedition to Finland. In 1840, he defended a master's dissertation on the legs of birds in relation to systematics. In 1842, his doctoral di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
