Eotetrapodiformes
Eotetrapodiformes is a clade of tetrapodomorphs including the four-limbed vertebrates ("tetrapods" in the traditional sense) and their closest finned relatives, two groups of stem tetrapods called tristichopterids and elpistostegalids. The clade was named in 2010 by Michael I. Coates and Matt Friedman, and is defined as "the node-based clade arising from the most recent common ancestor of ''Eusthenopteron'' and ''Ichthyostega'' plus all of its descendants". It thus excludes the basalmost tetrapodomorphs, such as the rhizodont Rhizodontida is an extinct group of predatory tetrapodomorphs known from many areas of the world from the Givetian through to the Pennsylvanian Pennsylvanian may refer to: * A person or thing from Pennsylvania * Pennsylvanian (geology) The ...s and megalichthyiforms. Cladogram from Swartz, 2012: References Extant Devonian first appearances Evolution of tetrapods {{Lobefinned-fish-stub ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Tetrapodomorph
The Tetrapodomorpha (also known as Choanata) are a clade of vertebrates consisting of tetrapods (four-limbed vertebrates) and their closest sarcopterygian relatives that are more closely related to living tetrapods than to living lungfish. Advanced forms transitional between fish and the early labyrinthodonts, such as ''Tiktaalik'', have been referred to as "fishapods" by their discoverers, being half-fish, half-tetrapods, in appearance and limb morphology. The Tetrapodomorpha contains the crown group tetrapods (the last common ancestor of living tetrapods and all of its descendants) and several groups of early stem tetrapods, which includes several groups of related lobe-finned fishes, collectively known as the osteolepiforms. The Tetrapodamorpha minus the crown group Tetrapoda are the Stem Tetrapoda, a paraphyletic unit encompassing the fish to tetrapod transition. Among the characteristics defining tetrapodomorphs are modifications to the fins, notably a humerus with convex h ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Platycephalichthys
''Platycephalichthys'' is a genus of tristichopterid lobe-finned fish which lived during the middle Devonian, upper Givetian stage. Phylogeny Below is a 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 ... from Swartz, 2012: See also * References Prehistoric lobe-finned fish genera Eotetrapodiforms Devonian bony fish {{paleo-lobefinned-fish-stub ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Platycephalichthys Bischoffi
''Platycephalichthys'' is a genus of tristichopterid lobe-finned fish which lived during the middle Devonian, upper Givetian stage. Phylogeny Below is a 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 d ... from Swartz, 2012: See also * References Prehistoric lobe-finned fish genera Eotetrapodiforms Devonian bony fish {{paleo-lobefinned-fish-stub ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Elpistostegalid
Elpistostegalia or Panderichthyida is an order of prehistoric lobe-finned fishes which lived during the Middle Devonian to Late Devonian period (about 385 to 374 million years ago). They represent the advanced tetrapodomorph stock, the fishes more closely related to tetrapods than the osteolepiform fishes. The earliest elpistostegalians, combining fishlike and tetrapod-like characters, are sometimes called fishapods, a phrase coined for the advanced elpistostegalian '' Tiktaalik''. Through a strict cladistic view, the order includes the terrestrial tetrapods. Palaeobiology of the elpistostegalians A rise in global oxygen content allowed for the evolution of large, predatory fish that were able to exploit the shallow tidal areas and swamplands as top predators. Several groups evolved to fill these niches, the most successful were the elpistiostegalians. In such environments, they would have been challenged by periodic oxygen deficiency. In comparable modern aquatic environmen ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Tetrapod
Tetrapods (; ) are four-limb (anatomy), limbed vertebrate animals constituting the superclass Tetrapoda (). It includes extant taxon, extant and extinct amphibians, sauropsids (reptiles, including dinosaurs and therefore birds) and synapsids (pelycosaurs, extinct therapsids and all extant mammals). Tetrapods evolved from a clade of primitive semiaquatic animals known as the Tetrapodomorpha which, in turn, evolved from ancient lobe-finned fish (sarcopterygians) around 390 million years ago in the Middle Devonian, Middle Devonian period; their forms were transitional between lobe-finned fishes and true four-limbed tetrapods. Limbed vertebrates (tetrapods in the broad sense of the word) are first known from Middle Devonian trackways, and body fossils became common near the end of the Late Devonian but these were all aquatic. The first crown group, crown-tetrapods (last common ancestors of extant tetrapods capable of terrestrial locomotion) appeared by the very early Mississippian ( ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Elpistostegalia
Elpistostegalia or Panderichthyida is an order of prehistoric lobe-finned fishes which lived during the Middle Devonian to Late Devonian period (about 385 to 374 million years ago). They represent the advanced tetrapodomorph stock, the fishes more closely related to tetrapods than the osteolepiform fishes. The earliest elpistostegalians, combining fishlike and tetrapod-like characters, are sometimes called fishapods, a phrase coined for the advanced elpistostegalian ''Tiktaalik''. Through a strict cladistic view, the order includes the terrestrial tetrapods. Palaeobiology of the elpistostegalians A rise in global oxygen content allowed for the evolution of large, predatory fish that were able to exploit the shallow tidal areas and swamplands as top predators. Several groups evolved to fill these niches, the most successful were the elpistiostegalians. In such environments, they would have been challenged by periodic oxygen deficiency. In comparable modern aquatic environments ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Tinirau Clackae
''Tinirau'' is an extinct genus of sarcopterygian fish from the Middle Devonian of Nevada. Although it spent its entire life in the ocean, ''Tinirau'' is a stem tetrapod close to the ancestry of land-living vertebrates in the crown group Tetrapoda. Relative to more well-known stem tetrapods, ''Tinirau'' is more closely related to Tetrapoda than is ''Eusthenopteron'', but farther from Tetrapoda than is ''Panderichthys''. The type and only species of ''Tinirau'' is ''T. clackae'', named in 2012. Description ''Tinirau'' was a fairly large, predatory fish about a meter long and with a deep, compact body. The head was large, with large terminal mout and numerous teeth. The tail was heterocercal, but the remaining fins with the exception of the pectoral fins was situated behind the middle of the body similar to the situation seen in pikes, giving the animal a large tail surface suitable for great bursts of speed. It shares many advanced features with later tetrapodomorphs in the ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Elginerpeton
''Elginerpeton'' is a genus of stegocephalian (stem-tetrapod), the fossils of which were recovered from Scat Craig, Morayshire in the UK, from rocks dating to the late Devonian Period (Early Famennian stage, 368 million years ago). The only known fossil has been given the name ''Elginerpeton pancheni''. ''Elginerpeton'' is known from skeletal fragments including a partial shoulder and hip, a femur, tibia (lower hind limb), and jaw fragments. The holotype is a lower jaw fragment estimated at 40 centimeters in total length. The total body is estimated to have measured about 1.5 m (5 ft) in length. Upon its description, ''Elginerpeton'' was allied with ''Obruchevichthys'' in the family Elginerpetontidae. A biomechanical analysis of stegocephalian jaws has indicated that ''Elginerpeton'' had an unusual feeding habit among tetrapod relatives. Its jaws were thin, and plotted as the most susceptible to high stresses among the sample group. However, the heavy sculpturing of ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Elginerpeton BW
''Elginerpeton'' is a genus of stegocephalian (stem-tetrapod), the fossils of which were recovered from Scat Craig, Morayshire in the UK, from rocks dating to the late Devonian Period (Early Famennian stage, 368 million years ago). The only known fossil has been given the name ''Elginerpeton pancheni''. ''Elginerpeton'' is known from skeletal fragments including a partial shoulder and hip, a femur, tibia (lower hind limb), and jaw fragments. The holotype is a lower jaw fragment estimated at 40 centimeters in total length. The total body is estimated to have measured about 1.5 m (5 ft) in length. Upon its description, ''Elginerpeton'' was allied with ''Obruchevichthys'' in the family Elginerpetontidae. A biomechanical analysis of stegocephalian jaws has indicated that ''Elginerpeton'' had an unusual feeding habit among tetrapod relatives. Its jaws were thin, and plotted as the most susceptible to high stresses among the sample group. However, the heavy sculpturing of th ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Eusthenopteron BW
''Eusthenopteron'' (from el, εὖ , 'good', el, σθένος , 'strength', and el, πτερόν 'wing' or 'fin') is a genus of prehistoric sarcopterygian (often called lobe-finned fishes) which has attained an iconic status from its close relationships to tetrapods. Early depictions of this animal show it emerging onto land; however, paleontologists now widely agree that it was a strictly aquatic animal.M. Laurin, F. J. Meunier, D. Germain, and M. Lemoine 2007A microanatomical and histological study of the paired fin skeleton of the Devonian sarcopterygian ''Eusthenopteron foordi'' ''Journal of Paleontology'' 81: 143–153. The genus ''Eusthenopteron'' is known from several species that lived during the Late Devonian period, about 385 million years ago. ''Eusthenopteron'' was first described by J. F. Whiteaves in 1881, as part of a large collection of fishes from Miguasha, Quebec. Some 2,000 ''Eusthenopteron'' specimens have been collected from Miguasha, one of which was ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Elpistostege
''Elpistostege'' is an extinct genus of finned tetrapodomorphs that lived during the late Givetian to early Frasnian ages of the Late Devonian epoch. Its only known species, ''E. watsoni'', was first described in 1938 by the British palaeontologist Thomas Stanley Westoll, based on a single partial skull roof discovered at the Escuminac Formation in Quebec, Canada. In 2010, a complete specimen was found in the same formation, which was described by Richard Cloutier and colleagues in 2020. It reveals that the paired fins of ''Elpistostege'' contained bones homologous to the phalanges (digit bones) of modern tetrapods; it is the most basal tetrapodomorph known to possess these bones. At the same time, the fins were covered in scales and lepidotrichia (fin rays), which indicates that the origin of phalanges preceded the loss of fin rays, rather than the other way around. Relationships An analysis conducted by Swartz in 2012 found ''Elpistostege'' to be the sister taxon of ''Tikta ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Tiktaalik BW
''Tiktaalik'' (; Inuktitut ) is a monospecific genus of extinct sarcopterygian (lobe-finned fish) from the Late Devonian Period, about 375 Mya (million years ago), having many features akin to those of tetrapods (four-legged animals). It may have grown up to in length. Unearthed in Arctic Canada, ''Tiktaalik'' is a non-tetrapod member of Osteichthyes (bony fish), complete with scales and gills – but it has a triangular, flattened head and unusual, cleaver-shaped fins. Its fins have thin ray bones for paddling like most fish, but they also have sturdy interior bones that would have allowed Tiktaalik to prop itself up in shallow water and use its limbs for support as most four-legged animals do. Those fins and other mixed characteristics mark ''Tiktaalik'' as a crucial transition fossil, a link in evolution from swimming fish to four-legged vertebrates. This and similar animals might be the common ancestors of all vertebrate terrestrial fauna: amphibians, reptiles, birds, and ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |