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Pachycormidae
Pachycormiformes is an extinct order of marine ray-finned fish known from the Early Jurassic to the end of the Cretaceous. It only includes a single family, Pachycormidae. They were characterized by having serrated pectoral fins (though more recent studies demonstrated that fin shape diversity in this group was high), reduced pelvic fins and a bony rostrum. Their exact relations with other fish are unclear, but they are generally considered to be teleosteomorphs, more closely related to teleosts than to Holostei. Pachycormiformes are morphologically diverse, containing both tuna and swordfish-like carnivorous forms, as well as edentulous suspension-feeding forms, with the latter including the largest ray finned fish known to have existed, ''Leedsichthys,'' with an estimated maximum length of 16 metres. Synapomorphies Pachycormiformes are united by "a compound bone (rostrodermethmoid) forming the anterodorsal border of the mouth; a reduced coronoid process of the mandible; ab ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Leedsichthys
''Leedsichthys'' is an extinct genus of pachycormid fish that lived in the oceans of the Middle to Late Jurassic.Liston, JJ (2004). An overview of the pachycormiform ''Leedsichthys''. In: Arratia G and Tintori A (eds) Mesozoic Fishes 3 - Systematics, Paleoenvironments and Biodiversity. Verlag Dr. Friedrich Pfeil, München, pp 379–390. It is the largest ray-finned fish, and amongst the largest fish known to have ever existed. The first remains of ''Leedsichthys'' were identified in the nineteenth century. Especially important were the finds by the British collector Alfred Nicholson Leeds, after whom the genus was named "Leeds' fish" in 1889. The type species is ''Leedsichthys problematicus''. ''Leedsichthys'' fossils have been found in England, France, Germany and Chile. In 1999, based on the Chilean discoveries, a second species was named ''Leedsichthys notocetes'', but this was later shown to be indistinguishable from ''L. problematicus''. ''Leedsichthys'' fossils have been ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pachycormidae Assortment
Pachycormiformes is an extinct order of marine ray-finned fish known from the Early Jurassic to the end of the Cretaceous. It only includes a single family, Pachycormidae. They were characterized by having serrated pectoral fins (though more recent studies demonstrated that fin shape diversity in this group was high), reduced pelvic fins and a bony rostrum. Their exact relations with other fish are unclear, but they are generally considered to be teleosteomorphs, more closely related to teleosts than to Holostei. Pachycormiformes are morphologically diverse, containing both tuna and swordfish-like carnivorous forms, as well as edentulous suspension-feeding forms, with the latter including the largest ray finned fish known to have existed, ''Leedsichthys,'' with an estimated maximum length of 16 metres. Synapomorphies Pachycormiformes are united by "a compound bone (rostrodermethmoid) forming the anterodorsal border of the mouth; a reduced coronoid process of the mandible; a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bonnerichthys
''Bonnerichthys'' is a genus of fossil fishes within the family Pachycormidae that lived during the Late Cretaceous Period Fossil remains of this taxon were first described from the Smoky Hill Member of the Niobrara Chalk Formation of Kansas (Late Coniacian-Early Campanian, about 87-81 million years ago), and additional material was later reported from the Pierre Shale, Mooreville Chalk, Demopolis Chalk, Wenonah Formation, and Moreno Formation, among other localities. It grew to around 6 m (20 ft) in length, substantially less than the related ''Leedsichthys'' from the Jurassic which likely grew up to 17 m (56 ft). Feeding One of the most significant features of ''Bonnerichthys'' is the recognition that it was a filter feeder, living on plankton. This recognition that many large-bodied fish from the Mesozoic in the Pachycormidae were filter feeders shows that this niche was filled for at least 100 million years before previously known. The modern niche is filled by several s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudoasthenocormus
''Pseudoasthenocormus'' is an extinct genus of ray-finned fish belonging to the family Pachycormidae. It contains one species, ''P. retrodorsalis''. It lived during the upper Jurassic (Kimmeridgian– Tithonian, about 152–148 million years ago) and its fossil remains have been found in Germany.Eastman, C. R. (1914). Catalog of the fossil fishes in the Carnegie Museum. Memoirs of the Carnegie Museum. Vol. VI. No. 7. Description Large in size, this fish easily exceeded one metre in length. Like many other similar genera, ''Pseudoasthenocormus'' possessed a robust and compact body, although generally more slender than '' Asthenocormus''. As indicated by the specific epithet, the dorsal fin is set back, originating just behind the anal, and is much shorter than the latter. The dorsal fin is composed of a few rays, which decrease in size posteriorly. The anal fin has become independent, with the rays (about 30) starting almost vertically from the haemal arches. The palate was equippe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protosphyraena
''Protosphyraena'' is a fossil genus of swordfish-like marine fish, that thrived worldwide during the Upper Cretaceous Period (Coniacian-Maastrichtian). Though fossil remains of this taxon have been found in both Europe and Asia, it is perhaps best known from the Smoky Hill Member of the Niobrara Chalk Formation of Kansas (Late Coniacian-Early Campanian). ''Protosphyraena'' was a large fish, averaging 2–3 metres in length. ''Protosphyraena'' shared the Cretaceous oceans with aquatic reptiles, such as mosasaurs and plesiosaurs, as well as with many other species of extinct predatory fish. The name ''Protosphyraena'' is a combination of the Greek word ''protos'' ("early") plus '' Sphyraena'', the genus name for barracuda, as paleontologists initially mistook ''Protosphyraena'' for an ancestral barracuda. Recent research shows that the genus ''Protosphyraena'' is not at all related to the true swordfish-family Xiphiidae, but belongs to the extinct family Pachycormidae. Histor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suspension Feeding
Filter feeders are a sub-group of suspension feeding animals that feed by straining suspended matter and food particles from water, typically by passing the water over a specialized filtering structure. Some animals that use this method of feeding are clams, krill, sponges, baleen whales, and many fish (including some sharks). Some birds, such as flamingos and certain species of duck, are also filter feeders. Filter feeders can play an important role in clarifying water, and are therefore considered ecosystem engineers. They are also important in bioaccumulation and, as a result, as indicator organisms. Fish Most forage fish are filter feeders. For example, the Atlantic menhaden, a type of herring, lives on plankton caught in midwater. Adult menhaden can filter up to four gallons of water a minute and play an important role in clarifying ocean water. They are also a natural check to the deadly red tide. Extensive article on the role of menhaden in the ecosystem and possible r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ohmdenia
''Ohmdenia'' is an extinct genus of prehistoric bony fish that lived from the Toarcian stage of the Early Jurassic epoch. ''Ohmdenia'' was first described in 1953 by B. Hauff, based on a fossil found in the well-known Posidonia Shale in Holzmaden, Germany. For a long time this animal has been considered a close relative of '' Birgeria'', a great predator typical of the Triassic period with an uncertain systematic position. Further studies have shown similarities with the Pachycormiformes, a group considered close to the origin of teleosts and also including giant forms and planktives (e.g. ''Leedsichthys''). Some studies have erroneously indicated ''Ohmdenia'' as a synonym of ''Saurostomus'', other studies have instead placed ''Ohmdenia'' as an important evolutionary passage between the basal pachicormiforms and the more derived planktivore pachicormiformes.Romano, C. & Brinkmann, W. 2009 Reappraisal of the lower actinopterygian ''Birgeria stensioei'' Aldinger, 1931 (Osteichthy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pachycormus (fish)
''Pachycormus'' (from el, παχύς , 'thick' and el, κορμός 'timber log') is an extinct genus of pachycormiform ray-finned fish known from the Early Jurassic (Toarcian stage) of Europe. The type species ''P. macropterus'' was first named as a species of ''Elops'' by Henri Marie Ducrotay de Blainville in 1818, it was placed into the newly named genus ''Pachycormus'' by Louis Agassiz in 1833. Fossils have been found in marine deposits from France, Germany and England. ''Pachycormus'' has recently been considered monotypic, only containing ''P.'' ''macropterus,'' with other species considered junior synonyms of the former, though this has subsequently been questioned. ''Pachycormus'' has generally been considered basal among Pachycormiformes, with a recent phylogeny finding it to be the second most basal pachycormiform after ''Euthynotus ''Euthynotus'' is an extinct genus of prehistoric bony fish that lived during the early Toarcian stage of the Early Jurassic epoch. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euthynotus
''Euthynotus'' is an extinct genus of prehistoric bony fish that lived during the early Toarcian stage of the Early Jurassic epoch. It is generally considered the basalmost pachycormiform. Species ''Euthynotus'' has two species classified within it: * ''Euthynotus incognitus'' Blainville, 1818 * ''Euthynotus intermedius'' Agassiz, 1839 See also * Prehistoric fish The evolution of fish began about 530 million years ago during the Cambrian explosion. It was during this time that the early chordates developed the skull and the vertebral column, leading to the first craniates and vertebrates. The first fis ... * List of prehistoric bony fish References Early Jurassic fish Pachycormiformes Jurassic fish of Europe {{Jurassic-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pectoral Fins
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as seen in sharks. Apart from the tail or caudal fin, fish fins have no direct connection with the spine and are supported only by muscles. Their principal function is to help the fish swim. Fins located in different places on the fish serve different purposes such as moving forward, turning, keeping an upright position or stopping. Most fish use fins when swimming, flying fish use pectoral fins for gliding, and frogfish use them for crawling. Fins can also be used for other purposes; male sharks and mosquitofish use a modified fin to deliver sperm, thresher sharks use their caudal fin to stun prey, reef stonefish have spines in their dorsal fins that inject venom, anglerfish use the first spine of their dorsal fin like a fishing rod to lur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspidorhynchiformes
Aspidorhynchiformes (from New Latin "shield-snout forms") is an extinct order of ray-finned fish. It contains only a single family, the Aspidorhynchidae. Members of the group are noted for their elongated, conical rostrums, of varying length, formed from fused premaxillae. They are generally interpreted as stem-group teleosts. The range of the group extends from the Middle Jurassic to the late Paleocene. Taxonomic history The order was described by Pieter Bleeker in 1859. Aspidorhynchiformes has one family, which is divided into at least two genera: * Order †Aspidorhynchiformes Bleeker 1859 spidorhynchida; Aspidorhynchoidei Bleeker 1859** Family †Aspidorhynchidae Bleeker 1859 inctiferidae Silva Santos 1990; Diphyodontidae Jordan 1923*** Genus †'' Jonoichthys'' Gouiric-Cavalli 2015 *** Genus ?†'' Ophirachis'' Costa 1854 *** Genus †'' Platycerhynchus'' Costa 1864 *** Genus †'' Pseudovinctifer'' Arratia 2015 *** Genus †'' Richmondichthys'' Bartholomai 2004 *** Genu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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