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Vendiidae
Vendiamorpha is a class of extinct animals within the Ediacaran phylum Proarticulata. The typical vendiamorph had an oval-shaped or round-shaped body divided completely into segmented isomers, that were arranged alternately in two rows with reference to the longitudinal axis of the body. Description The phenomenon of left-right alternating segments is called ''glide reflection symmetry'', and is a diagnostic feature of proarticulates. Transverse elements decrease in size from one end to the other and are inclined in the same direction. Typically, the first few, or largest initial isomers are fused together to form a headshield-like structure, leading some researchers to have originally considered them to be ancestral or related to arthropods, though, overwhelming evidence of them being proarticulates have since led researchers to discard this hypothetical relationship. Some vendiamorphs (e.g., ''Vendia'' and ''Paravendia'') supposedly demonstrate a digestive-distributive sy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paravendia Janae
''Paravendia'' is an extinct genus of proarticulate vendiamorph that lived in the Ediacaran period, about 553 million years ago. It shares the Vendiidae family with ''Vendia'' and ''Karakhtia''. It is a monotypic genus, with the species ''Paravendia janae''. Description It is an animal that presents 'bilateral' symmetry, similar in appearance to the previously mentioned genus '' Vendia '', with new isomers replacing the older ones. Distribution Ediacaran of the Russian Federation (Arkhangelsk). See also *List of ediacaran genera The existence of life, especially that of animals, before the Cambrian had long been the subject of debate in paleontology. The apparent suddenness of the Cambrian explosion had no firm explanation, and Charles Darwin himself recognized the chal ... References Notes Zakrevskaya, Maria. Paleoecological reconstruction of the Ediacaran benthic macroscopic communities of the White Sea (Russia). Palaeogeography, Palaeoclimatology, Palaeoecology 15 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karakhtia
''Karakhtia nessovi'' is a species of Proarticulate from the Ediacaran period, around 555 Million Years Ago. K. nessovi is the only species in the genus ''Karakhtia''. The genus '' Haootia'' has been compared minorly to ''Karakhtia'' in the way that the fossils of ''Haootia'' superficially resemble the crumpled margins of ''Karakhtia''. Discovery and name The holotype fossil of ''Karakhtia'' was found from the Ustʹ Pinega Formation, in the White Sea of Russia, and described in 2004. The generic name ''Karakhtia'' is derived from the place name ''Karakhta River'', near to where the fossil material was found. The specific name ''nessovi'' is derived from the surname of ''L.A. Nessov'', a Leningrad paleontologist. Description ''Karakhtia nessovi'' is a Proarticulate from the Vendiidae family, growing up to in length, and like other members of its family, it has a headshield-like structure. Unlike anything seen in other Proarticulates, it features a margin with radial fol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Karakhtia Nessovi
''Karakhtia nessovi'' is a species of Proarticulate from the Ediacaran period, around 555 Million Years Ago. K. nessovi is the only species in the genus ''Karakhtia''. The genus ''Haootia'' has been compared minorly to ''Karakhtia'' in the way that the fossils of ''Haootia'' superficially resemble the crumpled margins of ''Karakhtia''. Discovery and name The holotype fossil of ''Karakhtia'' was found from the Ustʹ Pinega Formation, in the White Sea of Russia, and described in 2004. The generic name ''Karakhtia'' is derived from the place name ''Karakhta River'', near to where the fossil material was found. The specific name ''nessovi'' is derived from the surname of ''L.A. Nessov'', a Leningrad paleontologist. Description ''Karakhtia nessovi'' is a Proarticulate from the Vendiidae family, growing up to in length, and like other members of its family, it has a headshield-like structure. Unlike anything seen in other Proarticulates, it features a margin with radial folds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proarticulata
Proarticulata is a proposed phylum of extinct, near-bilaterally symmetrical animals known from fossils found in the Ediacaran (Vendian) marine deposits, and dates to approximately . The name comes from the Greek () = "before" and Articulata, i.e. prior to animals with true segmentation such as annelids and arthropods. This phylum was established by Mikhail A. Fedonkin in 1985 for such animals as ''Dickinsonia'', '' Vendia'', '' Cephalonega'', '' Praecambridium'' and currently many other Proarticulata are described (see list). Due to their simplistic morphology, their affinities and mode of life are subject to debate. They are almost universally considered to be metazoans, and due to possessing a clear central axis have been suggested to be stem-bilaterians. In the traditional interpretation, the Proarticulatan body is divided into transverse articulation (division) into isomers as distinct from the transverse articulation segments in annelids and arthropods, as their individu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudovendia
The "ivesheadiomorphs" are a group of fossilised structures known from Ediacaran localities in England and Newfoundland. They are considered to be taphomorphs, representing the poorly preserved biological remains of various contemporary taxa such as ''Charnia'', '' Charniodiscus'', ''Bradgatia'', '' Primocandelabrum'', ''Pectinifrons'' and others, that were effaced by partial decay by micro-organisms following death on the seafloor before burial by sediment. Ivesheadiomorph structures were previously described as distinct organisms, namely ''Ivesheadia lobata'' ("pizza disk"), ''Blackbrookia oaksi'', ''Shepshedia palmata'' and ''Pseudovendia charnwoodensis''. However, all of these fossils have since been rejected as valid taxa. See also * List of Ediacaran genera The existence of life, especially that of animals, before the Cambrian had long been the subject of debate in paleontology. The apparent suddenness of the Cambrian explosion had no firm explanation, and Charles Darwin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Russia
Russia, or the Russian Federation, is a country spanning Eastern Europe and North Asia. It is the list of countries and dependencies by area, largest country in the world, and extends across Time in Russia, eleven time zones, sharing Borders of Russia, land borders with fourteen countries. Russia is the List of European countries by population, most populous country in Europe and the List of countries and dependencies by population, ninth-most populous country in the world. It is a Urbanization by sovereign state, highly urbanised country, with sixteen of its urban areas having more than 1 million inhabitants. Moscow, the List of metropolitan areas in Europe, most populous metropolitan area in Europe, is the capital and List of cities and towns in Russia by population, largest city of Russia, while Saint Petersburg is its second-largest city and Society and culture in Saint Petersburg, cultural centre. Human settlement on the territory of modern Russia dates back to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudofossil
Pseudofossils are inorganic objects, markings, or impressions that might be mistaken for fossils. Pseudofossils may be misleading, as some types of mineral deposits can mimic lifeforms by forming what appear to be highly detailed or organized structures. One common example is when manganese oxides crystallize with a characteristic tree-like or dendritic pattern along a rock fracture. The formation of frost dendrites on a window is another common example of this crystal growth. Concretions are sometimes thought to be fossils, and occasionally one contains a fossil, but are generally not fossils themselves. Chert or flint nodules in limestone can often take forms that resemble fossils. Background Pyrite disks or spindles are sometimes mistaken for fossils of sand dollars or other forms (see marcasite). Cracks, bumps, gas bubbles, and such can be difficult to distinguish from true fossils. Specimens that cannot be attributed with certainty to either fossils or pseudofossils are t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arkhangelsk Oblast
Arkhangelsk Oblast ( rus, Архангельская область, p=ɐrˈxanɡʲɪlʲskəjə ˈobɫəsʲtʲ) is a federal subjects of Russia, federal subject of Russia (an oblast). It includes the Arctic Ocean, Arctic archipelagos of Franz Josef Land and Novaya Zemlya, as well as the Solovetsky Islands in the White Sea. Arkhangelsk Oblast also has administrative jurisdiction over the Nenets Autonomous Okrug (NAO). Including the NAO, Arkhangelsk Oblast has an area of , it is the largest of List of first-level administrative divisions by area, first-level administrative divisions in Europe. Its population (including the NAO) was 1,227,626 as of the Russian Census (2010), 2010 Census. The classification of inhabited localities in Russia, city of Arkhangelsk, with a population of 301,199 as of the 2021 Census, is the administrative center of the oblast.Charter, Article 5 The second largest city is the nearby Severodvinsk, home to Sevmash, a major shipyard for the Russian N ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
