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Ray-finned Fish Suborders
Actinopterygii (; ), members of which are known as ray-finned fish or actinopterygians, is a class of bony fish that comprise over 50% of living vertebrate species. They are so called because of their lightly built fins made of webbings of skin supported by radially extended thin bony spines called ''lepidotrichia'', as opposed to the bulkier, fleshy lobed fins of the sister clade Sarcopterygii (lobe-finned fish). Resembling folding fans, the actinopterygian fins can easily change shape and wetted area, providing superior thrust-to-weight ratios per movement compared to sarcopterygian and chondrichthyian fins. The fin rays attach directly to the proximal or basal skeletal elements, the radials, which represent the articulation between these fins and the internal skeleton (e.g., pelvic and pectoral girdles). The vast majority of actinopterygians are teleosts. By species count, they dominate the subphylum Vertebrata, and constitute nearly 99% of the over 30,000 extant species of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ludlow Epoch
In the geological timescale, the Ludlow Epoch (from 427.4 ± 0.5 million years ago to 423.0 ± 2.3 million years ago) occurred during the Silurian Period, after the end of the Homerian Age. It is named for the town of Ludlow in Shropshire, England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It .... The Ludlow Epoch is subdivided into two stages: Gorstian and Ludfordian. See also * Ludlow Group References *03 Geological epochs {{geochronology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leafy Seadragon
The leafy seadragon (''Phycodurus eques'') or Glauert's seadragon, is a marine fish. It is the only member of the genus ''Phycodurus'' in the family Syngnathidae, which includes seadragons, pipefish, and seahorses. It is found along the southern and western coasts of Australia. The name is derived from their appearance, with long leaf-like protrusions coming from all over the body. These protrusions are not used for propulsion; they serve only as camouflage. The leafy seadragon propels itself utilising a pair of pectoral fins on the sides of its neck and a dorsal fin on its back closer to the tail end. These small fins are almost completely transparent and difficult to see as they undulate minutely to move the creature sedately through the water, completing the illusion of floating seaweed. Popularly known as "leafies", they are the marine emblem of the state of South Australia and a focus for local marine conservation. Taxonomy The generic name is derived from the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
McGraw-Hill Education
McGraw Hill is an American education science company that provides educational content, software, and services for students and educators across various levels—from K-12 to higher education and professional settings. They produce textbooks, digital learning tools, and adaptive technology to enhance learning experiences and outcomes. It is one of the "big three" educational publishers along with Houghton Mifflin Harcourt and Pearson Education. McGraw Hill also publishes reference and trade publications for the medical, business, and engineering professions. Formerly a division of The McGraw Hill Companies (later renamed McGraw Hill Financial, now S&P Global), McGraw Hill Education was divested and acquired by Apollo Global Management in March 2013 for $2.4 billion in cash. McGraw Hill was sold in 2021 to Platinum Equity for $4.5 billion. History McGraw Hill was founded in 1888, when James H. McGraw, co-founder of McGraw Hill, purchased the ''American Journal of Railw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Osteichthyes
Osteichthyes ( ; ), also known as osteichthyans or commonly referred to as the bony fish, is a Biodiversity, diverse clade of vertebrate animals that have endoskeletons primarily composed of bone tissue. They can be contrasted with the Chondrichthyes (cartilaginous fish) and the extinct placoderms and acanthodians, which have endoskeletons primarily composed of cartilage. The vast majority of extant taxon, extant fish are members of Osteichthyes, being an extremely diverse and abundant group consisting of 45 order (biology), orders, over 435 family (biology), families and 28,000 species. The group is divided into two main clades, the ray-finned fish (Actinopterygii, which makes up the vast majority of extant fish) and the lobe-finned fish (Sarcopterygii, which gave rise to all land vertebrates, i.e. tetrapods). The oldest known fossils of bony fish are about 425 million years old from the late Silurian, which are also transitional fossils showing a dentition, tooth pattern th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Class (biology)
In biological classification, class () is a taxonomic rank, as well as a taxonomic unit, a taxon, in that rank. It is a group of related taxonomic orders. Other well-known ranks in descending order of size are domain, kingdom, phylum, order, family, genus, and species, with class ranking between phylum and order. History The class as a distinct rank of biological classification having its own distinctive name – and not just called a ''top-level genus'' ''(genus summum)'' – was first introduced by French botanist Joseph Pitton de Tournefort in the classification of plants that appeared in his '' Eléments de botanique'' of 1694. Insofar as a general definition of a class is available, it has historically been conceived as embracing taxa that combine a distinct ''grade'' of organization—i.e. a 'level of complexity', measured in terms of how differentiated their organ systems are into distinct regions or sub-organs—with a distinct ''type'' of construction, whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adolf Von Klein
Adolf (also spelt Adolph or Adolphe, Adolfo, and when Latinised Adolphus) is a given name with German origins. The name is a compound derived from the Old High German ''Athalwolf'' (or ''Hadulf''), a composition of ''athal'', or ''adal'', meaning "noble" (or '' had(u)''-, meaning "battle, combat"), and ''wolf''. The name is cognate to the Anglo-Saxon name '' Æthelwulf'' (also Eadulf or Eadwulf). The name can also be derived from the ancient Germanic elements "Wald" meaning "power", "brightness" and wolf (Waldwulf). Due to its extremely negative associations with the Nazi leader Adolf Hitler, the name has greatly declined in popularity since the end of World War II. Similar names include Lithuanian Adolfas and Latvian Ādolfs. The female forms Adolphine and Adolpha are far more rare than the male names. Adolphus can also appear as a surname, as in John Adolphus, the English historian. Popularity and usage During the 19th and early 20th centuries, Adolf was a popular nam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teleostei
Teleostei (; Ancient Greek, Greek ''teleios'' "complete" + ''osteon'' "bone"), members of which are known as teleosts (), is, by far, the largest group of ray-finned fishes (class Actinopterygii), with 96% of all neontology, extant species of fish. The Teleostei, which is variously considered a Division (zoology), division or an infraclass in different taxonomic systems, include over 26,000 species that are arranged in about 40 order (biology), orders and 448 family (biology), families. Teleosts range from giant oarfish measuring or more, and ocean sunfish weighing over , to the minute male anglerfish ''Photocorynus spiniceps'', just long. Including not only torpedo-shaped fish built for speed, teleosts can be flattened vertically or horizontally, be elongated cylinders or take specialised shapes as in anglerfish and seahorses. The difference between teleosts and other bony fish lies mainly in their jaw bones; teleosts have a movable premaxilla and corresponding modifications ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teleosteomorpha
Teleosteomorpha is an infraclass of ray-finned fishes containing all teleost fish and their closest extinct relatives. Also in this group are two diverse Mesozoic fish orders, the Aspidorhynchiformes and the Pachycormiformes. Several other non-teleostomorph teleosteans existed throughout the Mesozoic, although not as dominant as the two main clades in the group. Shared morphological features of this group include a autosphenotic bone lacking a dermal component, the lack of a canal bearing part of the antorbital bone, the lack of vertebral centra fused into the occipital condyle in adult individuals, and each hypural (caudal fin support) being articulated with caudal rays. The oldest known teleosteomorph is '' Prohalecites'' from the Triassic of Italy. The last surviving non-teleostean teleosteomorph was '' Belonostomus'', which survived into the Late Paleocene. Taxonomy Cladogram of Teleosteomorpha after Sferco et al. 2021: The cladogram below is simplified after a phylogen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holostei
Holostei is a group of ray-finned bony fish. It is divided into two major clades, the Halecomorphi, represented by the single living genus, '' Amia'' with two species, the bowfins (''Amia calva'' and '' Amia ocellicauda''), as well as the Ginglymodi, the sole living representatives being the gars (Lepisosteidae), represented by seven living species in two genera ('' Atractosteus'', '' Lepisosteus''). The earliest members of the clade, which are putative " semionotiforms" such as '' Acentrophorus'' and '' Archaeolepidotus'', are known from the Middle to Late Permian and are among the earliest known neopterygians. Holostei was thought to be regarded as paraphyletic. However, a recent study provided evidence that the Holostei are the closest living relatives of the Teleostei, both within the Neopterygii. This was found from the morphology of the Holostei, for example presence of a paired vomer. Holosteans are closer to teleosts than are the chondrosteans, the other group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neopterygii
Neopterygii (from Greek νέος ''neos'' 'new' and πτέρυξ ''pteryx'' 'fin') is a subclass of ray-finned fish (Actinopterygii). Neopterygii includes the Holostei and the Teleostei, of which the latter comprise the vast majority of extant fishes, and over half of all living vertebrate species. While living holosteans include only freshwater taxa, teleosts are diverse in both freshwater and marine environments. Many new species of teleosts are scientifically described each year. The potentially oldest known neopterygian is the putative " semionotiform" '' Acentrophorus varians'' from the Middle Permian of Russia; however, one study incorporating morphological data from fossils and molecular data from nuclear and mitochondrial DNA, places this divergence date at least 284 mya (million years ago), during the Artinskian stage of the Early Permian. Another study suggests an even earlier split (360 myr ago, near the Devonian-Carboniferous boundary). Evolution a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chondrostei
Chondrostei is a subclass of non- neopterygian ray-finned fish. While the term originally referred to the paraphyletic grouping of all non-neopterygian ray-finned fish, it was redefined by Patterson in 1982 to be a clade comprising the Acipenseriformes (which includes sturgeon and paddlefish) and their extinct relatives. Taxa commonly suggested to represent relatives of the Acipenseriformes include the Triassic marine fish '' Birgeria'' and the Saurichthyiformes, but their relationship with the Acipenseriformes has been strongly challenged on cladistic grounds. Coccolepididae, a group of small weakly ossified Jurassic and Cretaceous fish found in both marine and freshwater environments, have also been suggested to be close relatives of the Acipenseriformes. However, this has never been subject to cladistic analysis. Near & Thacker (2024) also recovered the ptycholepiform '' Boreosomus'' as a stem-acipenseriform. The following taxa are known: * Subclass Chondrostei ** Genus � ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Actinopteri
Actinopteri () is the sister group of Cladistia (bichirs) in the class Actinopterygii (ray-finned fish). Dating back to the Permian period, the Actinopteri comprise the Chondrostei (sturgeons and paddlefish), the Holostei ( bowfins and gars), and the teleosts; in other words, all extant ray-finned fish other than the bichirs. In this clade the lungs have evolved into a swim bladder. Characters of Actinopteri include paired fin structure, a single dorsal fin, fulcra, a large median gular and numerous branchiostegals, ganoid scales, and a valvula cerebelli in the brain. Classification The following cladogram summarizes the evolutionary relationships of extant Actinopteri. Divergence time for each clade In biology, a clade (), also known as a Monophyly, monophyletic group or natural group, is a group of organisms that is composed of a common ancestor and all of its descendants. Clades are the fundamental unit of cladistics, a modern approach t ... in mya are based on: ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
