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Aytonerpeton
''Aytonerpeton'' is an extinct genus of stem-tetrapod from the Ballagan Formation of Scotland. It was one of five new genera of early limbed vertebrates from the Ballagan Formation described by Clack ''et al.'' in 2016. These vertebrates were among the only known in the world from a period of time known as Romer's gap. Romer's gap, which spans most of the Mississippian age of the Carboniferous The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the ..., is characterized by a comparative rarity of tetrapod and stem-tetrapod fossils compared to the periods of time directly older and younger than it. However, ''Aytonerpeton'' and other Ballagan stem-tetrapods help to close in this gap in the vertebrate fossil record. References {{Taxonbar, from=Q56281038 Stegocephali Fossil taxa descri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2016 In Paleontology
Flora Plants Fungi Cnidarians Research * ''Yunnanoascus haikouensis'', previously thought to be a member of Ctenophora, is reinterpreted as a Crown group, crown-group medusozoan by Han ''et al.'' (2016). * A study on the fossil corals from the Late Triassic (Norian) outcrops in Antalya Province (Turkey), indicating that the corals lived in symbiosis with Photosynthesis, photosynthesizing dinoflagellate algae, is published by Frankowiak ''et al.'' (2016). New taxa Arthropods Bryozoans Brachiopods Molluscs Echinoderms Conodonts Fishes Amphibians Research * A study on the histology and growth histories of the Humerus, humeri of the specimens of ''Acanthostega'' recovered from the mass-death deposit of Stensiö Bjerg (Greenland) is published by Sanchez ''et al.'' (2016), who argue that even the largest individuals from this deposit are juveniles. * Fossils of a tetrapod resembling ''Ichthyostega'' and a probable Whatcheeriidae, whatcheeriid-Evolutionary grade, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stegocephali
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 re-estab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ballagan Formation
The Ballagan Formation is a Formation (geology), geologic formation in Scotland and England. It preserves fossils dating back to the early part of the Carboniferous Period (geology), period (Tournaisian – early Visean). Its name comes from the "Ballagan Beds" of Ballagan Glen, near Strathblane, which has a good example of this geological formation. The Ballagan Formation was historically known as the Cementstone Group, but more recently it has been placed as the middle formation of the Inverclyde Group. This change was motivated by the recognition that the youngest parts of the Devonian Upper Old Red Sandstone (now known as the Kinnesswood Formation) were geologically continuous with the lowest parts of the Lower Carboniferous Calciferous Sandstone Measures (now known as the Ballagan and Clyde Sandstone Formation, Clyde Sandstone formations). This interval of Devonian-Carboniferous overlap was named the Inverclyde Group, and the cementstone-rich "drab beds" in the middle of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Romer's Gap
Romer's gap is an apparent gap in the Paleozoic tetrapod fossil record noted in the studies of paleontology and evolutionary biology, which represent periods in the Early Carboniferous from which excavators have not yet found relevant transitional fossils. It is named after American paleontologist Alfred Romer, who first recognised it in 1956. Recent discoveries in Scotland and Australia are beginning to close this gap in palaeontological knowledge. Age Romer's gap runs from approximately 360 to 345 million years ago, corresponding to the first 15 million years of the Carboniferous, the early Mississippian (starting with the Tournaisian and moving into the Visean). The gap forms a discontinuity between the primitive forests and high diversity of fishes at the end Devonian and more modern aquatic and terrestrial assemblages of the early Carboniferous. Mechanism behind the gap There has been long debate as to why there are so few fossils from this time period. Some have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Carboniferous
Early may refer to: Places in the United States * Early, Iowa, a city * Early, Texas, a city * Early Branch, a stream in Missouri * Early County, Georgia * Fort Early, Georgia, an early 19th century fort Music * Early B, stage name of Jamaican dancehall and reggae deejay Earlando Arrington Neil (1957–1994) * Early James, stage name of American singer-songwriter Fredrick Mullis Jr. (born 1993) * Early (Scritti Politti album), ''Early'' (Scritti Politti album), 2005 * Early (A Certain Ratio album), ''Early'' (A Certain Ratio album), 2002 * Early Records, a record label Other uses * Early (name), a list of people and fictional characters with the given name or surname * Early effect, an effect in transistor physics * Early, a synonym for ''hotter'' in Stellar classification#"Early" and "late" nomenclature, stellar classification See also * * The Earlies, a 21st century band * Earley (other) * Earlie, a given name {{disambiguation, geo ... [...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] |
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] |
Mississippian Age
The Mississippian ( ), also known as Lower Carboniferous or Early Carboniferous, is a subperiod in the geologic timescale or a subsystem of the geologic record. It is the earlier of two subperiods of the Carboniferous period lasting from roughly 358.9 to 323.2 million years ago. As with most other geochronologic units, the rock beds that define the Mississippian are well identified, but the exact start and end dates are uncertain by a few million years. The Mississippian is so named because rocks with this age are exposed in the Mississippi Valley. The Mississippian was a period of marine transgression in the Northern Hemisphere: the sea level was so high that only the Fennoscandian Shield and the Laurentian Shield were dry land. The cratons were surrounded by extensive delta systems and lagoons, and carbonate sedimentation on the surrounding continental platforms, covered by shallow seas. In North America, where the interval consists primarily of marine limestones, it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carboniferous
The Carboniferous ( ) is a Geologic time scale, geologic period and System (stratigraphy), system of the Paleozoic era (geology), era that spans 60 million years, from the end of the Devonian Period Ma (million years ago) to the beginning of the Permian Period, Ma. It is the fifth and penultimate period of the Paleozoic era and the fifth period of the Phanerozoic eon (geology), eon. In North America, the Carboniferous is often treated as two separate geological periods, the earlier Mississippian (geology), Mississippian and the later Pennsylvanian (geology), Pennsylvanian. The name ''Carboniferous'' means "coal-bearing", from the Latin ("coal") and ("bear, carry"), and refers to the many coal beds formed globally during that time. The first of the modern "system" names, it was coined by geologists William Conybeare (geologist), William Conybeare and William Phillips (geologist), William Phillips in 1822, based on a study of the British rock succession. Carboniferous is the per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
