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Mcmurdodontidae
''Mcmurdodus'' is an extinct genus of sharks and the sole member of the family Mcmurdodontidae, in the order Hexanchiformes The Hexanchiformes are the order consisting of the most primitive types of sharks, and numbering just seven extant species. Fossil sharks that were apparently very similar to modern sevengill species are known from Jurassic specimens. Hexanchi .... It contains two extinct species.Ginter, M. & Hampe, O. & Duffin, C.J. (2010) Handbook of Paleoichthyology, Vol. 3D: Chondrichthyes Paleozoic Elasmobranchii: Teeth Verlag Dr. Friedrich Pfeil, pp. 168, 154 fig., 4 Tab. Species * '' Mcmurdodus featherensis'' White, 1968 * '' Mcmurdodus whitei'' Turner, & Young, 1987 References {{Taxonbar, from=Q18358508 Devonian sharks Hexanchiformes Prehistoric fish of Australia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexanchiformes
The Hexanchiformes are the order consisting of the most primitive types of sharks, and numbering just seven extant species. Fossil sharks that were apparently very similar to modern sevengill species are known from Jurassic specimens. Hexanchiform sharks have only one dorsal fin, either six or seven gill slits, and no nictitating membrane in the eyes. Shark teeth similar to those modern hexanchids are known from Devonian deposits in Antarctica and Australia, as well as Permian deposits in Japan. If these are in fact hexanchids, this may be the only extant order of elasmobranchs to have survived after the Permian extinction (and by extension, the oldest extant order of elasmobranchs). The frilled sharks of the genus ''Chlamydoselachus'' are very different from the cow sharks, and have been proposed to be moved to a distinct order, Chlamydoselachiformes. Classification Living species *Family Chlamydoselachidae Garman 1884 (frilled sharks) **''Chlamydoselachus'' Garman, 1884 ** ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mcmurdodus Featherensis
''Mcmurdodus'' is an extinct genus of sharks and the sole member of the family Mcmurdodontidae, in the order Hexanchiformes The Hexanchiformes are the order consisting of the most primitive types of sharks, and numbering just seven extant species. Fossil sharks that were apparently very similar to modern sevengill species are known from Jurassic specimens. Hexanchi .... It contains two extinct species.Ginter, M. & Hampe, O. & Duffin, C.J. (2010) Handbook of Paleoichthyology, Vol. 3D: Chondrichthyes Paleozoic Elasmobranchii: Teeth Verlag Dr. Friedrich Pfeil, pp. 168, 154 fig., 4 Tab. Species * '' Mcmurdodus featherensis'' White, 1968 * '' Mcmurdodus whitei'' Turner, & Young, 1987 References {{Taxonbar, from=Q18358508 Devonian sharks Hexanchiformes Prehistoric fish of Australia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mcmurdodus Whitei
''Mcmurdodus'' is an extinct genus of sharks and the sole member of the family Mcmurdodontidae, in the order Hexanchiformes. It contains two extinct species.Ginter, M. & Hampe, O. & Duffin, C.J. (2010) Handbook of Paleoichthyology, Vol. 3D: Chondrichthyes Paleozoic Elasmobranchii: Teeth Verlag Dr. Friedrich Pfeil, pp. 168, 154 fig., 4 Tab. Species * ''Mcmurdodus featherensis ''Mcmurdodus'' is an extinct genus of sharks and the sole member of the family Mcmurdodontidae, in the order Hexanchiformes The Hexanchiformes are the order consisting of the most primitive types of sharks, and numbering just seven extant sp ...'' White, 1968 * '' Mcmurdodus whitei'' Turner, & Young, 1987 References {{Taxonbar, from=Q18358508 Devonian sharks Hexanchiformes Prehistoric fish of Australia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus comes above species and below family (taxonomy), family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shark
Sharks are a group of elasmobranch fish characterized by a cartilaginous skeleton, five to seven gill slits on the sides of the head, and pectoral fins that are not fused to the head. Modern sharks are classified within the clade Selachimorpha (or Selachii) and are the sister group to the rays. However, the term "shark" has also been used to refer to all extinct members of Chondrichthyes with a shark-like morphology, such as hybodonts and xenacanths. The oldest modern sharks are known from the Early Jurassic. They range in size from the small dwarf lanternshark (''Etmopterus perryi''), a deep sea species that is only in length, to the whale shark (''Rhincodon typus''), the largest fish in the world, which reaches approximately in length. Sharks are found in all seas and are common to depths up to . They generally do not live in freshwater, although there are a few known exceptions, such as the bull shark and the river shark, which can be found in both seawater and fresh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Family (biology)
Family ( la, familia, plural ') is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between order and genus. A family may be divided into subfamilies, which are intermediate ranks between the ranks of family and genus. The official family names are Latin in origin; however, popular names are often used: for example, walnut trees and hickory trees belong to the family Juglandaceae, but that family is commonly referred to as the "walnut family". What belongs to a family—or if a described family should be recognized at all—are proposed and determined by practicing taxonomists. There are no hard rules for describing or recognizing a family, but in plants, they can be characterized on the basis of both vegetative and reproductive features of plant species. Taxonomists often take different positions about descriptions, and there may be no broad consensus across the scientific community for some time. The publishing of new data and opini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Order (biology)
Order ( la, wikt:ordo#Latin, ordo) is one of the eight major hierarchical taxonomic ranks in Linnaean taxonomy. It is classified between Family_(biology), family and Class_(biology), class. In biological classification, the order is a taxonomic rank used in the classification of organisms and recognized by the nomenclature codes. An immediately higher rank, superorder, is sometimes added directly above order, with suborder directly beneath order. An order can also be defined as a group of related families. What does and does not belong to each order is determined by a taxonomist, as is whether a particular order should be recognized at all. Often there is no exact agreement, with different taxonomists each taking a different position. There are no hard rules that a taxonomist needs to follow in describing or recognizing an order. Some taxa are accepted almost universally, while others are recognized only rarely. The name of an order is usually written with a capital letter. Fo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian Sharks
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 al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
