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Adelogyrinids
Adelospondyli is an order of elongated, presumably aquatic, Carboniferous amphibians (''sensu lato''). They have a robust skull roofed with solid bone, and orbits located towards the front of the skull. The limbs were almost certainly absent, although some historical sources reported them to be present. Despite the likely absence of limbs, adelospondyls retained a large part of the bony shoulder girdle. Adelospondyls have been assigned to a variety of groups in the past. They have traditionally been seen as members of the subclass Lepospondyli, related to other unusual early tetrapods such as " microsaurs", " nectrideans", and aïstopods. Analyses such as Ruta & Coates (2007) have offered an alternate classification scheme, arguing that adelospondyls were actually far removed from other lepospondyls, instead being stem-tetrapod stegocephalians closely related to the family Colosteidae. Most adelospondyls belong to the family Adelogyrinidae, and prior to 2003 the order and family ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acherontiscus
''Acherontiscus'' is an extinct genus of stegocephalians that lived in the Early Carboniferous (Mississippian era) of Scotland. The type and only species is ''Acherontiscus caledoniae'', named by paleontologist Robert Carroll in 1969. Members of this genus have an unusual combination of features which makes their placement within amphibian-grade tetrapods uncertain. They possess multi-bone vertebrae similar to those of embolomeres, but also a skull similar to lepospondyls. The only known specimen of ''Acherontiscus'' possessed an elongated body similar to that of a snake or eel. No limbs were preserved, and evidence for their presence in close relatives of ''Acherontiscus'' is dubious at best. Phylogenetic analyses created by Marcello Ruta and other paleontologists in the 2000s indicate that ''Acherontiscus'' is part of Adelospondyli, closely related to other snake-like animals such as '' Adelogyrinus'' and '' Dolichopareias''. Adelospondyls are traditionally placed within the gro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adelogyrinidae
Adelospondyli is an Order (biology), order of elongated, presumably aquatic, Carboniferous amphibians (''Sensu, sensu lato''). They have a robust skull roofed with solid bone, and Orbit (anatomy), orbits located towards the front of the skull. The limbs were almost certainly absent, although some historical sources reported them to be present. Despite the likely absence of limbs, adelospondyls retained a large part of the bony shoulder girdle. Adelospondyls have been assigned to a variety of groups in the past. They have traditionally been seen as members of the subclass Lepospondyli, related to other unusual early Tetrapod, tetrapods such as "Microsauria, microsaurs", "Nectridea, nectrideans", and Aistopoda, aïstopods. Analyses such as Ruta & Coates (2007) have offered an alternate classification scheme, arguing that adelospondyls were actually far removed from other lepospondyls, instead being Crown group#Stem groups, stem-tetrapod Stegocephalia, stegocephalians closely related ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lepospondyli
Lepospondyli is a diverse clade of early tetrapods. With the exception of one late-surviving lepospondyl from the Late Permian of Morocco ('' Diplocaulus minimus''), lepospondyls lived from the Visean stage of the Early Carboniferous to the Early Permian and were geographically restricted to what is now Europe and North America. Five major groups of lepospondyls are known: Adelospondyli; Aïstopoda; Lysorophia; Microsauria; and Nectridea. Lepospondyls have a diverse range of body forms and include species with newt-like, eel- or snake-like, and lizard-like forms. Various species were aquatic, semiaquatic, or terrestrial. None were large (the biggest genus, the diplocaulid '' Diplocaulus'', reached a meter in length, but most were much smaller), and they are assumed to have lived in specialized ecological niches not taken by the more numerous temnospondyl amphibians that coexisted with them in the Paleozoic. Lepospondyli was named in 1888 by Karl Alfred von Zittel, who coi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adelospondylus
''Adelospondylus'' is an extinct adelospondyl tetrapodomorph from the Carboniferous of what is now Scotland Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjac .... References External links2D, stereoscopic, and 3D imagery of the type specimen of Adelospondylus watsoni Adelospondyli Mississippian sarcopterygians of Europe [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colosteidae
Colosteidae is a Family (biology), family of stegocephalians (stem-group tetrapod, tetrapods) that lived in the Carboniferous period. They possessed a variety of characteristics from different tetrapod or stem-tetrapod groups, which made them historically difficult to classify. They are now considered to be part of a lineage intermediate between the earliest Devonian terrestrial vertebrates (such as ''Ichthyostega''), and the different groups ancestral to all modern tetrapods, such as temnospondyls (probably ancestral to modern amphibians) and reptiliomorphs (ancestral to amniotes such as mammals, reptiles, and birds). Description Colosteids had elongated bodies, with an estimated 40 vertebrae, not including the tail. The skull is relatively flat and composed of many separate bones, like that of other stegocephalians. Colosteids lacked Otic notch, otic notches at the back of the head, unlike temnospondyls and other "labyrinthodonts". However, they did possess large mandibular an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crown Group
In phylogenetics, the crown group or crown assemblage is a collection of species composed of the living representatives of the collection, the most recent common ancestor of the collection, and all descendants of the most recent common ancestor. It is thus a way of defining a clade, a group consisting of a species and all its extant or extinct descendants. For example, Neornithes (birds) can be defined as a crown group, which includes the most recent common ancestor of all modern birds, and all of its extant or extinct descendants. The concept was developed by Willi Hennig, the formulator of phylogenetic systematics, as a way of classifying living organisms relative to their extinct relatives in his "Die Stammesgeschichte der Insekten", and the "crown" and "stem" group terminology was coined by R. P. S. Jefferies in 1979. Though formulated in the 1970s, the term was not commonly used until its reintroduction in 2000 by Graham Budd and Sören Jensen. Contents of the crow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrapod
A tetrapod (; from Ancient Greek :wiktionary:τετρα-#Ancient Greek, τετρα- ''(tetra-)'' 'four' and :wiktionary:πούς#Ancient Greek, πούς ''(poús)'' 'foot') is any four-Limb (anatomy), limbed vertebrate animal of the clade Tetrapoda (). Tetrapods include all Neontology#Extant taxa versus extinct taxa, extant and Extinction, extinct amphibians and amniotes, with the latter in turn Evolution, evolving into two major clades, the Sauropsida, sauropsids (reptiles, including dinosaurs and therefore birds) and synapsids (extinct pelycosaur, "pelycosaurs", therapsids and all extant mammals, including Homo sapiens, humans). Hox gene mutations have resulted in some tetrapods becoming Limbless vertebrate, limbless (snakes, legless lizards, and caecilians) or two-limbed (cetaceans, sirenians, Bipedidae, some lizards, kiwi (bird), kiwis, and the extinct moa and elephant birds). Nevertheless, they still qualify as tetrapods through their ancestry, and some retain a pair of ves ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stegocephalia
Stegocephali (often spelled Stegocephalia, from Greek , lit. "roofed head") is a clade of vertebrate animals containing all fully limbed tetrapodomorphs. It is equivalent to a broad definition of the superclass Tetrapoda: under this broad definition, the term "tetrapod" applies to any animal descended from the first vertebrate with four limbs each with digits in the extremity ( pentadactyly), rather than fins of their sarcopterygian relatives. Stegocephalians include both the modern lineage of limbed vertebrates (the crown group tetrapods, including modern amphibians, reptiles, birds and mammals) as well as a portion of the stem group, the earliest limbed tetrapodomorphs such as '' Ichthyostega'' and '' Acanthostega'', which evolved in the Devonian period long before the origin of the crown group. Many paleontologists prefer a stricter definition of Tetrapoda which applies solely to the crown group, excluding earlier types of limbed tetrapodomorphs. Stegocephali was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scotland
Scotland is a Countries of the United Kingdom, country that is part of the United Kingdom. It contains nearly one-third of the United Kingdom's land area, consisting of the northern part of the island of Great Britain and more than 790 adjacent Islands of Scotland, islands, principally in the archipelagos of the Hebrides and the Northern Isles. To the south-east, Scotland has its Anglo-Scottish border, only land border, which is long and shared with England; the country is surrounded by the Atlantic Ocean to the north and west, the North Sea to the north-east and east, and the Irish Sea to the south. The population in 2022 was 5,439,842. Edinburgh is the capital and Glasgow is the most populous of the cities of Scotland. The Kingdom of Scotland emerged as an independent sovereign state in the 9th century. In 1603, James VI succeeded to the thrones of Kingdom of England, England and Kingdom of Ireland, Ireland, forming a personal union of the Union of the Crowns, three kingdo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scientific Classification
image:Hierarchical clustering diagram.png, 280px, Generalized scheme of taxonomy Taxonomy is a practice and science concerned with classification or categorization. Typically, there are two parts to it: the development of an underlying scheme of classes (a taxonomy) and the allocation of things to the classes (classification). Originally, taxonomy referred only to the Taxonomy (biology), classification of organisms on the basis of shared characteristics. Today it also has a more general sense. It may refer to the classification of things or concepts, as well as to the principles underlying such work. Thus a taxonomy can be used to organize species, documents, videos or anything else. A taxonomy organizes taxonomic units known as "taxa" (singular "taxon"). Many are hierarchy, hierarchies. One function of a taxonomy is to help users more easily find what they are searching for. This may be effected in ways that include a library classification system and a Taxonomy for search e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serpukhovian
The Serpukhovian is in the ICS geologic timescale the uppermost stage or youngest age of the Mississippian, the lower subsystem of the Carboniferous. The Serpukhovian age lasted from Ma to Ma. It is preceded by the Visean and is followed by the Bashkirian. The Serpukhovian correlates with the lower part of the Namurian Stage of European stratigraphy and the middle and upper parts of the Chesterian Stage of North American stratigraphy. Name and definition The Serpukhovian Stage was proposed in 1890 by Russian stratigrapher Sergei Nikitin and was introduced in the official stratigraphy of European Russia in 1974. It was named after the city of Serpukhov, near Moscow. The ICS later used the upper Russian subdivisions of the Carboniferous in its international geologic time scale. The base of the Serpukhovian is informally defined by the first appearance of the conodont '' Lochriea ziegleri'', though the utility and systematic stability of this species is not yet certain. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
