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Holoptychiid
Porolepiformes is an order of prehistoric lobe-finned fish which lived during the Devonian period (about 416 to 359 million years ago). The group contains two families: Holoptychiidae and Porolepididae. Porolepiformes was established by the Swedish paleontologist Erik Jarvik, and were thought to have given rise to the salamanders and caecilians independently of the other tetrapods. He based this conclusion on the shapes of the snouts of the aforementioned groups. This view is no longer in favour in Paleontology. Jarvik also claimed the existence of choanae in porolepiformes which linked them to tetrapods, but this has remained controversial. Recent phylogenetic reconstruction places porolepiformes close to lungfishes. More recent evidence has shown that at least one genus ''Laccognathus'' was most likely amphibious Amphibious means able to use either land or water. In particular it may refer to: Animals * Amphibian, a vertebrate animal of the class Amphibia (many ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glyptolepis (fish)
''Glyptolepis'' is an extinct genus of porolepiform lobe-finned fish which lived during Devonian Period, from the early Eifelian to Frasnian Age Age or AGE may refer to: Time and its effects * Age, the amount of time someone or something has been alive or has existed ** East Asian age reckoning, an Asian system of marking age starting at 1 * Ageing or aging, the process of becoming older .... References Porolepiformes Prehistoric lobe-finned fish genera Devonian bony fish Fossil taxa described in 1841 Fossils of Russia {{paleo-lobefinned-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holoptychius
''Holoptychius'' (from el, όλος , 'whole' and el, πτυχή 'fold') is an extinction, extinct genus of porolepiform lobe-finned fish from the Middle Devonian to Carboniferous (Mississippian (geology), Mississippian) periods. It is known from fossils worldwide. The genus was first described by Louis Agassiz in 1839. Description ''Holoptychius'' was a streamlined predator about long (though largest specimen could grew up to ), which fed on other bony fish. Its rounded scales and body form indicate that it could have swum quickly through the water to catch prey. Similar to other rhipidistians, it had fang-like teeth on its palate in addition to smaller teeth on the jaws. Its asymmetrical tail sported a caudal fin on its lower end. To compensate for the downward push caused by this fin placement, the pectoral fins of ''Holoptychius'' were placed high on the body. Species Of the genus ''Holoptychius'' the following species have been described: * ''H. americanus'' * ''H. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Duffichthys
''Duffichthys'' is a genus of prehistoric lobe-finned fish which lived during the Late Devonian period. Fossils have been found at the locality of Scat Craig, Scotland.Ahlberg, P. E., 1992: ''A new holoptychiid porolepiform fish from the Upper Frasnian of Elgin, Scotland''. ''Palaeontology Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossi ...'', 35. 813-828. References Porolepiformes Prehistoric lobe-finned fish genera Devonian bony fish Late Devonian animals Late Devonian fish Fossils of Great Britain {{paleo-lobefinned-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holoptychius Quebecensis -"salamanderfisk"
''Holoptychius'' (from el, όλος , 'whole' and el, πτυχή 'fold') is an extinct genus of porolepiform lobe-finned fish from the Middle Devonian to Carboniferous ( Mississippian) periods. It is known from fossils worldwide. The genus was first described by Louis Agassiz in 1839. Description ''Holoptychius'' was a streamlined predator about long (though largest specimen could grew up to ), which fed on other bony fish. Its rounded scales and body form indicate that it could have swum quickly through the water to catch prey. Similar to other rhipidistians, it had fang-like teeth on its palate in addition to smaller teeth on the jaws. Its asymmetrical tail sported a caudal fin on its lower end. To compensate for the downward push caused by this fin placement, the pectoral fins of ''Holoptychius'' were placed high on the body. Species Of the genus ''Holoptychius'' the following species have been described: * ''H. americanus'' * ''H. andersoni'' * ''H. bergmanni'' (Down ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caecilian
Caecilians (; ) are a group of limbless, vermiform or serpentine amphibians. They mostly live hidden in the ground and in stream substrates, making them the least familiar order of amphibians. Caecilians are mostly distributed in the tropics of South and Central America, Africa, and southern Asia. Their diet consists of small subterranean creatures such as earthworms. All modern caecilians and their closest fossil relatives are grouped as a clade, Apoda , within the larger group Gymnophiona , which also includes more primitive extinct caecilian-like amphibians. The name derives from the Greek words γυμνος (''gymnos'', naked) and οφις (''ophis'', snake), as the caecilians were originally thought to be related to snakes. The body is cylindrical dark brown or bluish black in colour. The skin is slimy and bears grooves or ringlike markings. Description Caecilians completely lack limbs, making the smaller species resemble worms, while the larger species, with lengths up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrapod
Tetrapods (; ) are four-limbed vertebrate animals constituting the superclass Tetrapoda (). It includes 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 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-tetrapods (last common ancestors of extant tetrapods capable of terrestrial locomotion) appeared by the very early Carboniferous, 350 million years ago. The specific aquatic ancestors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleontology
Paleontology (), also spelled palaeontology or palæontology, is the scientific study of life that existed prior to, and sometimes including, the start of the Holocene epoch (roughly 11,700 years before present). It includes the study of fossils to classify organisms and study their interactions with each other and their environments (their paleoecology). Paleontological observations have been documented as far back as the 5th century BC. The science became established in the 18th century as a result of Georges Cuvier's work on comparative anatomy, and developed rapidly in the 19th century. The term itself originates from Greek (, "old, ancient"), (, ( gen. ), "being, creature"), and (, "speech, thought, study"). Paleontology lies on the border between biology and geology, but differs from archaeology in that it excludes the study of anatomically modern humans. It now uses techniques drawn from a wide range of sciences, including biochemistry, mathematics, and engineering. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Choanae
The choanae (singular choana), posterior nasal apertures or internal nostrils are two openings found at the back of the nasal passage between the nasal cavity and the throat in tetrapods, including humans and other mammals (as well as crocodilians and most skinks). They are considered one of the most important synapomorphies of tetrapodomorphs, that allowed the passage from water to land. In animals with secondary palates, they allow breathing when the mouth is closed. Janvier, Philippe (2004) "Wandering nostrils". ''Nature'', 432 (7013): 23–24. In tetrapods without secondary palates their function relates primarily to olfaction (sense of smell). The choanae are separated in two by the vomer. Boundaries A choana is the opening between the nasal cavity and the nasopharynx. It is therefore not a structure but a space bounded as follows: * anteriorly and inferiorly by the horizontal plate of palatine bone, * superiorly and posteriorly by the sphenoid bone * laterally by th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphibious Fish
Amphibious fish are fish that are able to leave water for extended periods of time. About 11 distantly related genera of fish are considered amphibious. This suggests that many fish genera independently evolved amphibious traits, a process known as convergent evolution. These fish use a range of terrestrial locomotory modes, such as lateral undulation, tripod-like walking (using paired fins and tail), and jumping. Many of these locomotory modes incorporate multiple combinations of pectoral-, pelvic-, and tail-fin movement. Many ancient fish had lung-like organs, and a few, such as the lungfish and bichir, still do. Some of these ancient "lunged" fish were the ancestors of tetrapods. In most recent fish species, though, these organs evolved into the swim bladders, which help control buoyancy. Having no lung-like organs, modern amphibious fish and many fish in oxygen-poor water use other methods, such as their gills or their skin to breathe air. Amphibious fish may also have ey ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleontological Journal
''Paleontological Journal'' (Russian: ''Paleontologicheskii Zhurnal'') is a monthly peer-reviewed Russian journal of paleontology established in 1959. It focuses on the paleontology and the fossil records of Eastern Europe and Asia. Articles are published simultaneously in Russian and English. The journal is edited by Alexei Yu. Rozanov and published by MAIK Nauka/Interperiodica. Editors-in-Chief *Acad. Yuri A. Orlov (1959–1966) *Dr. Vasily E. Ruzhentsev (1967–1978) *Acad. Leonid P. Tatarinov (1978–1988, 1994–2001) *Dr. Igor S. Barskov (1988–1993) *Acad. Alexei Yu. Rozanov (since 2001) Abstracting and indexing ''Paleonotological Journal'' is indexed and abstracted in: According to the ''Journal Citation Reports'', the journal has a 2011 impact factor of 0.454. See also * ''Palaeoworld ''Palaeoworld'' is a peer-reviewed academic journal with a focus on palaeontology and stratigraphy research in and around China. It was founded in 1991 by the Nanjing In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Erik Jarvik
Anders Erik Vilhelm Jarvik (30 November 1907 – 11 January 1998) was a Swedish paleontologist who worked extensively on the sarcopterygian (or lobe-finned) fish ''Eusthenopteron''. In a career that spanned some 60 years, Jarvik produced some of the most detailed anatomical work on this fish, making it arguably the best known fossil vertebrate. Jarvik was born at a farm in Utby Parish near Mariestad in northern Västergötland. He studied botany, zoology, geology, and paleontology at Uppsala University, where he took his licentiate's degree in 1937. In 1942, he completed his PhD with the dissertation ''On the structure of the snout of Crossopterygians and lower Gnathostomes in general''. He participated in the Greenland expedition of Gunnar Säve-Söderbergh in 1932 and was appointed assistant in the Department of Palaeozoology of the Swedish Museum of Natural History in Stockholm in 1937; he eventually succeeded Erik Stensiö as professor and head of the department in 1960 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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