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Xerodromes
Dissorophoideans are a clade of medium-sized, temnospondyl amphibians that appeared during the Moscovian in Euramerica, and continued through to the Late Permian and the Early Triassic of Gondwana. They are distinguished by various details of the skull, and many forms seem to have been well adapted for life on land. Since 2008, Lissamphibia has been progressively widely considered part of this clade, but this position is still disputed by some authors. It is possible that the small Permo-Carboniferous Micromelerpetontidae and the large Late Permian Melosauridae may also belong in this clade. Phylogeny An extensive phylogenetic analysis of dissorophoids conducted in 2016 and 2018 found that the families Dissorophidae and Trematopidae are more closely related to each other than either is to the family Amphibamidae. Following a 2008 study, the Dissorophidae-Trematopidae clade was called Olsoniformes. Below is the cladogram from the 2018 analysis: References * Huttenlocker, Ad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Branchiosauridae
Branchiosauridae is an extinct family of small amphibamiform temnospondyls with external gills and an overall juvenile appearance. The family has been characterized by hundreds of well-preserved specimens from the Permo-Carboniferous of Middle Europe.Schoch, R.R. 2008. The intrarelationships and evolutionary history of the temnospondyl family branchiosauridae. Journal of Systematic Palaeontology. 6(4):409-431. Specimens represent well defined ontogenetic stages and thus the taxon has been described to display paedomorphy (perennibranchiate). However, more recent work has revealed branchiosaurid taxa that display metamorphosing trajectories.Schoch, R.R. and Frobisch, N.B. 2006. Alternative Pathways in an Extinct Amphibian Clade. Evolution. 60(7):1467-1475 The name Branchiosauridae (“Branchio” in Ancient Greek denoting gills and “saurus” meaning lizard) refers to the retention of gills. Geological/paleoenvironmental information Branchiosaurids mostly inhabited Permo-Carbo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Temnospondyli
Temnospondyli (from Greek τέμνειν, ''temnein'' 'to cut' and σπόνδυλος, ''spondylos'' 'vertebra') is a diverse order of small to giant tetrapods—often considered primitive amphibians—that flourished worldwide during the Carboniferous, Permian, and Triassic periods. A few species continued into the Jurassic and Cretaceous periods. Fossils have been found on every continent. During about 210 million years of evolutionary history, they adapted to a wide range of habitats, including freshwater, terrestrial, and even coastal marine environments. Their life history is well understood, with fossils known from the larval stage, metamorphosis, and maturity. Most temnospondyls were semiaquatic, although some were almost fully terrestrial, returning to the water only to breed. These temnospondyls were some of the first vertebrates fully adapted to life on land. Although temnospondyls are considered amphibians, many had characteristics, such as scales and armour-like bon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphibamidae
The Amphibamidae are an extinct family of dissorophoid temnospondyls known from Late Carboniferous-Early Permian strata in the United States. Classification Amphibamidae has traditionally included small-bodied, terrestrial dissorophoids. The name is attributed to Moodie (1909), but it was rarely used because it originally referred only to ''Amphibamus''. Similar monogeneric families were also erected for other small, terrestrial dissorophoids (e.g., Doleserpetontidae), and most of the taxa now recognized as amphibamiforms were placed within the Dissorophidae. Clack & Milner (1993) revived the Amphibamidae to include ''Amphibamus, Platyrhinops, Doleserpeton,'' and ''Tersomius'.'' Daly (1994) further expanded the composition of the Amphibamidae to include the newly described ''Eoscopus'' as well as the Early Triassic form ''Micropholis''. She suggested that the micromelerpetids were also amphibamids, which has not been validated by more recent workers. Subsequent phylogenetic wor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphibamiformes
Amphibamiformes is an unranked clade with Dissorophoidea created by Schoch (2018). It encompasses all of the taxa traditionally considered to be "amphibamids" (subsequently restricted to '' Doleserpeton annectens'' and '' Amphibamus grandiceps'' by Schoch), branchiosaurids, and hypothetically lissamphibians under the traditional temnospondyl hypothesis of lissamphibian origins. These taxa are typically small-bodied dissorophoids and form the sister group to Olsoniformes, which comprises dissorophids and trematopids. Diagnosis (1) Palatine and ectopterygoid reduced to narrow struts; (2) interpterygoid vacuity greatly expanded laterally; (3) humerus length:waist ratio of 6:10; (4) basioccipital and supraoccipital absent. Definition The most inclusive clade containing ''Amphibamus grandiceps'' but not '' Dissorophus multicinctus''. Phylogeny Simplified phylogeny of Dissorophoidea from Schoch (2018): The phylogeny of Amphibamiformes has historically been relatively unreso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olsoniformes
Olsoniformes is a clade of dissorophoid temnospondyls. It includes the families Dissorophidae and Trematopidae. Most members of the clade were highly adapted to a terrestrial lifestyle. The clade was named in 2008 and is defined as the least inclusive clade containing ''Dissorophus multicinctus'' (a dissorophid) and ''Acheloma cumminsi'' (a trematopid) but not ''Amphibamus grandiceps, Micromelerpeton credneri,'' and ''Apateon pedestris''. Olsoniforms share various features such as a stout and low ilium and a thin cultriform process. Trematopids are known from the Late Carboniferous and the Early Permian of Europe and across much of North America, while dissorophids are primarily found in Early Permian deposits in the central United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pennsylvanian (geology)
The Pennsylvanian ( , also known as Upper Carboniferous or Late Carboniferous) is, in the International Commission on Stratigraphy, ICS geologic timescale, the younger of two period (geology), subperiods (or upper of two system (stratigraphy), subsystems) of the Carboniferous Period. It lasted from roughly . As with most other geochronology, geochronologic units, the stratum, rock beds that define the Pennsylvanian are well identified, but the exact date of the start and end are uncertain by a few hundred thousand years. The Pennsylvanian is named after the U.S. state of Pennsylvania, where the coal-productive beds of this age are widespread. The division between Pennsylvanian and Mississippian (geology), Mississippian comes from North American stratigraphy. In North America, where the early Carboniferous beds are primarily marine limestones, the Pennsylvanian was in the past treated as a full-fledged geologic period between the Mississippian and the Permian. In parts of Europe, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Moscovian (Carboniferous)
The Moscovian is in the International Commission on Stratigraphy, ICS geologic timescale a stage (stratigraphy), stage or age (geology), age in the Pennsylvanian (geology), Pennsylvanian, the youngest system (stratigraphy), subsystem of the Carboniferous. The Moscovian age lasted from to Megaannum, Ma, is preceded by the Bashkirian and is followed by the Kasimovian. The Moscovian overlaps with the European regional Westphalian (stage), Westphalian stage and the North American Atokan and Desmoinesian stages. Name and definition The Moscovian Stage was introduced by Sergei Nikitin (geologist), Sergei Nikitin (1850 - 1909) in 1890, using brachiopods in the Moscow Basin of European Russia. Nikitin named the stage after Moscow, then a major city and now the capital of Russia. The base of the Moscovian is close to the first appearances of the conodonts ''Declinognathodus donetzianus'' and ''Idiognathoides postsulcatus'' or otherwise the fusulinid ''Aljutovella aljutovica''. Because th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euramerica
Laurasia () was the more northern of two large landmasses that formed part of the Pangaea supercontinent from around ( Mya), the other being Gondwana. It separated from Gondwana (beginning in the late Triassic period) during the breakup of Pangaea, drifting farther north after the split and finally broke apart with the opening of the North Atlantic Ocean c. 56 Mya. The name is a portmanteau of Laurentia and Asia. Laurentia, Avalonia, Baltica, and a series of smaller terranes, collided in the Caledonian orogeny c. 400 Ma to form Laurussia (also known as Euramerica, or the Old Red Sandstone Continent). Laurussia then collided with Gondwana to form Pangaea. Kazakhstania and Siberia were then added to Pangaea 290–300 Ma to form Laurasia. Laurasia finally became an independent continental mass when Pangaea broke up into Gondwana and Laurasia. Terminology and origin of the concept Laurentia, the Palaeozoic core of North America and continental fragments that now make ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lopingian
The Lopingian is the uppermost series/last epoch of the Permian. It is the last epoch of the Paleozoic. The Lopingian was preceded by the Guadalupian and followed by the Early Triassic. The Lopingian is often synonymous with the informal terms late Permian or upper Permian. The name was introduced by Amadeus William Grabau in 1931 and derives from Leping, Jiangxi in China. It consists of two stages/ ages. The earlier is the Wuchiapingian and the later is the Changhsingian. The International Chronostratigraphic Chart (v2018/07) provides a numerical age of 259.1 ±0.5 Ma. If a Global Boundary Stratotype Section and Point (GSSP) has been approved, the lower boundary of the earliest stage determines numerical age of an epoch. The GSSP for the Wuchiapingian has a numerical age of 259.8 ± 0.4 Ma. Evidence from Milankovitch cycles suggests that the length of an Earth day during this epoch was approximately 22 hours. The Lopingian ended with the Permian–Triassic extinction event. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apomorphy
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have evolved in their most recent common ancestor. ) In cladistics, synapomorphy implies homology. Examples of apomorphy are the presence of erect gait, fur, the evolution of three middle ear bones, and mammary glands in mammals but not in other vertebrate animals such as amphibians or reptiles, which have retained their ancestral traits of a sprawling gait and lack of fur. Thus, these derived traits are also synapomorphies of mammals in general as they are not shared by other vertebrate animals. Etymology The word —coined by German entomologist Willi Hennig—is derived from the Ancient Greek words (''sún''), meaning "with, together"; (''apó''), meaning "away from"; and (''morphḗ''), meaning "shape, form". Clade analysis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gondwana
Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages of break-up, involving the separation of Antarctica from South America (forming the Drake Passage) and Australia, occurred during the Paleogene. Gondwana was not considered a supercontinent by the earliest definition, since the landmasses of Baltica, Laurentia, and Siberia were separated from it. To differentiate it from the Indian region of the same name (see ), it is also commonly called Gondwanaland. Gondwana was formed by the accretion of several cratons. Eventually, Gondwana became the largest piece of continental crust of the Palaeozoic Era, covering an area of about , about one-fifth of the Earth's surface. During the Carboniferous Period, it merged with Laurasia to form a larger supercontinent called Pangaea. Gondwana (and Pan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladogram
A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to descendants, nor does it show how much they have changed, so many differing evolutionary trees can be consistent with the same cladogram. A cladogram uses lines that branch off in different directions ending at a clade, a group of organisms with a last common ancestor. There are many shapes of cladograms but they all have lines that branch off from other lines. The lines can be traced back to where they branch off. These branching off points represent a hypothetical ancestor (not an actual entity) which can be inferred to exhibit the traits shared among the terminal taxa above it. This hypothetical ancestor might then provide clues about the order of evolution of various features, adaptation, and other evolutionary narratives about ance ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
