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Eugeneodontid
The Eugeneodontida is an extinct and poorly known order of cartilaginous fishes. They possessed "tooth-whorls" on the symphysis of either the lower or both jaws and pectoral fins supported by long radials. They probably lacked pelvic fins and anal fins. The palatoquadrate was either fused to the skull or reduced. Now determined to be within the Holocephali, their closest living relatives are ratfish. The eugeneodonts are named after paleontologist Eugene S. Richardson, Jr. The Eugeneodontida disappeared in the Early Triassic. Members of the Eugeneodontida are further classified into different families, the most well-preserved members that have been discovered are commonly placed within the families Helicoprionidae ("spiral saws"), and Edestidae ("those which devour"), the former containing the genera ''Helicoprion'', ''Sarcoprion'', and ''Parahelicoprion'', and the latter containing the genera ''Edestus'', '' Lestrodus'', and '' Metaxyacanthus''. All eugeneodonts are thought to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fadenia
''Fadenia'' is an extinct genus of eugeneodontid holocephalian chondrichthyan from the Carboniferous Period of Missouri (United States), the Permian period of Greenland, and the Early Triassic epoch of Greenland and Sulphur Mountain Formation of British Columbia, Canada. Eugeneodontida are an extinct order of Chondrichthyes. They are characterized by the presence of tooth whorls. They include iconic genera, such as ''Helicoprion'' (buzz-saw shark), ''Ornithoprion'', ''Edestus'' or '' Caseodus''. ''Fadenia'' is one of the few eugeneodontid genera that survived the end-Permian mass extinction event. It is one of the last surviving genera of this clade. It could reach about in length. The first fossils of Fadenia were discovered and written about in the periodical Meddelelser om Grønland in 1932 by the Danish vertebrate palaeontologist Eigil Nielsen after studying the Upper Permian beds of Cape Stosch, in the fjord of Godthab Gulf in King Christian X Land, Greenland. He ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caseodus
''Caseodus'' is an extinct genus of eugeneodontid holocephalian from the Carboniferous of the United States (Illinois, Indiana, Kansas, South Dakota) and the Early Triassic of Canada (British Columbia). It was of medium size, measuring in length. Eugeneodontida are an extinct order of Chondrichthyes. They are characterized by the presence of tooth whorls. They include iconic genera, such as ''Helicoprion'' ("buzz-saw shark"), ''Ornithoprion'', ''Edestus'' or ''Fadenia ''Fadenia'' is an extinct genus of eugeneodontid holocephalian chondrichthyan from the Carboniferous Period of Missouri (United States), the Permian period of Greenland, and the Early Triassic epoch of Greenland and Sulphur Mountain Formati ...''. ''Caseodus'' is one of the few eugeneodontid genera that survived the end-Permian mass extinction event. It is one of the last surviving genera of this clade. ''Caseodus'' is named after the late paleoichthyologist Gerard Case. References * Caseodo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parahelicoprion
''Parahelicoprion'' is an extinct genus of shark-like eugeneodontid holocephalids from the Permian of the Ural Mountains (Russia) and Copacabana Formation, Bolivia. The genus name, from "nearly coiled saw" in Greek, directly refers to ''Helicoprion'', a related holocephalid that shares similar traits to it, including the helical whorl of teeth. Description One of the primary qualities that separate ''Parahelicoprion'' from ''Helicoprion'' is the shape, thickness, and angle of the tooth whorl. Its teeth protrude outwards not like a tightly coiled saw, but instead a curved arrangement of cutting blades indicating it relied less on crushing slow-moving invertebrates and catching cephalopods, or other small mollusk prey, but inflicting traumatic damage against more durable, faster prey. Their teeth grew at a much slower pace than those of other whorl-tooth sharks, resulting in a depreciated spiral, growing only half of the teeth a ''Helicoprion'' would grow in its lifetime. The too ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sarcoprion
''Sarcoprion'' (from the Ancient Greek for "flesh saw") is an extinct genus of eugeneodontid holocephalids from the Permian of Greenland. Similar to other eugeneodontids such as ''Edestus'' and ''Helicoprion'', it was best known for its extremely bizarre tooth morphology compared to other species of sharks and their closest relatives, the chimaeras. Compared to other members of the Helicoprionidae (teeth of Agassiz), its "tooth whorls" were found to be sharper, more compact, and in better condition than other sharks of the time, and refrained from growing to extremely unwieldy forms that would raise questions about its ability to feed properly. The genus contains one species, ''Sarcoprion edax'' ("gluttonous flesh saw"), found in Permian-aged marine strata of ''Meddelelser om Grønland''. Description ''Sarcoprion'' had a jaw and mouth structure which allowed it to be more hydrodynamic, reducing the size and shape of the tooth whorl and increasing the size of the rostrum. ''Sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicoprion
''Helicoprion'' is an extinct genus of shark-like eugeneodont fish. Almost all fossil specimens are of spirally arranged clusters of the individuals' teeth, called "tooth whorls", which in life were embedded in the lower jaw. As with most extinct cartilaginous fish, the skeleton is mostly unknown. Fossils of ''Helicoprion'' are known from a 20 million year timespan during the Permian period from the Artinskian stage of the Cisuralian (Early Permian) to the Roadian stage of the Guadalupian (Middle Permian). The closest living relatives of ''Helicoprion'' (and other eugeneodonts) are the chimaeras, though their relationship is very distant. The unusual tooth arrangement is thought to have been an adaption for feeding on soft bodied prey, and may have functioned as a deshelling mechanism for hard bodied cephalopods such as nautiloids and ammonoids. In 2013, systematic revision of ''Helicoprion'' via morphometric analysis of the tooth whorls found only ''H. davisii, H. bessonowi'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edestus
''Edestus'' is an extinct genus of edestoid cartilaginous fish known from the Late Carboniferous (Pennsylvanian) of the United Kingdom, Russia, and the United States. Most remains consist of isolated curved blades or "whorls" that are studded with teeth, that in life were situated within the jaws. ''Edestus'' is a Greek name derived from the word ''edeste'' (to devour), in reference to the aberrant quality and size of the species' teeth. The largest species, ''E. heinrichi'', has been conservatively estimated to reach greater than 6.7 m (22 ft) in length, around the size of the largest known great white shark. Like its other relatives, such as ''Helicoprion'', and unlike modern sharks, the species of ''Edestus'' grew teeth in curved blades or "whorls". In ''Edestus''' case, only a single row of teeth occurred in the midline of each jaw, leading ''Edestus'' to sometimes be described as the "scissor tooth shark". The degree of curvature in the teeth brackets, along with s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caseodontoidea
The Eugeneodontida is an extinct and poorly known order of cartilaginous fishes. They possessed "tooth-whorls" on the symphysis of either the lower or both jaws and pectoral fins supported by long radials. They probably lacked pelvic fins and anal fins. The palatoquadrate was either fused to the skull or reduced. Now determined to be within the Holocephali, their closest living relatives are ratfish. The eugeneodonts are named after paleontologist Eugene S. Richardson, Jr. The Eugeneodontida disappeared in the Early Triassic. Members of the Eugeneodontida are further classified into different families, the most well-preserved members that have been discovered are commonly placed within the families Helicoprionidae ("spiral saws"), and Edestidae ("those which devour"), the former containing the genera ''Helicoprion'', '' Sarcoprion'', and '' Parahelicoprion'', and the latter containing the genera '' Edestus'', '' Lestrodus'', and '' Metaxyacanthus''. All eugeneodonts are thoug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Romerodus
''Romerodus'' is an extinct genus of eugeneodontid holocephalian from the Carboniferous of North America. Fossils have been found in Nebraska Nebraska () is a state in the Midwestern region of the United States. It is bordered by South Dakota to the north; Iowa to the east and Missouri to the southeast, both across the Missouri River; Kansas to the south; Colorado to the so .... References Caseodontidae Animals described in 1981 {{paleo-cartilaginous-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bobbodus
''Bobbodus'' is an extinct genus of eugeneodont shark from the Carboniferous and Permian periods. ''B. schaefferi'' is the type species and is known from three specimens, all from what was the eastern coast of the Panthallasic Ocean. They were found in the Kasimovian of Iowa, Gzhelian of Nebraska, Asselian of Kansas. Specimens of this species show the partial upper and lower dentition, the palatoquadrate, and gill arch. ''B. xerxesi'' is known from a single tooth found in Wuchiapingian-aged deposits in the Baghuk Mountains of central Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkm .... It is named for Xerxes, a famous Archaemenid ruler from the area whose monuments impressed the first author of the paper describing it.Hampe, O., Hairapetian, V., Dorka, M., Witzmann, F., Ak ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helicoprionidae
The Helicoprionidae, also known as the Agassizodontidae are an extinct, poorly known family of bizarre holocephalids within the poorly understood order Eugeneodontida. Members of the Helicoprionidae possessed a unique "tooth-whorl" on the symphysis A symphysis (, pl. symphyses) is a fibrocartilaginous fusion between two bones. It is a type of cartilaginous joint, specifically a secondary cartilaginous joint. # A symphysis is an amphiarthrosis, a slightly movable joint. # A growing togethe ... of the lower jaw and pectoral fins supported by long radials. The closest living relatives of the Helicoprionidae and all other eugeneodontids are the ratfishes. The anatomy of the tooth-whorl differed amongst genus and species, some possessing complete spirals (such as those of '' Helicoprion''), others possessing halved spirals (seen in '' Parahelicoprion''), and some with wedged half-spirals (seen in '' Sarcoprion''). Each tooth-whorl is thought to be adapted to a different type of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edestidae
The Edestidae are a poorly known, extinct family of shark-like eugeneodontid holocephalid cartilaginous fish. Similar to the related family Helicoprionidae, members of this family possessed a unique "tooth-whorl" on the symphysis of the lower jaw and pectoral fins supported by long radials. In addition to having a tooth-whorl on the lower jaw, at least one species of the genus ''Edestus'' had a second tooth-whorl in the upper jaw. The palatoquadrate was either fused to the skull or reduced. Edestids, along with the rest of the Eugeneodontida, are placed within the Holocephali.Tapanila, L., Pruitt, J., Pradel, A., Wilga, C., Ramsay, J., Schlader, R., Didier, D. 2013. Jaws for a spiral-tooth whorl: CT images reveal novel adaptation and phylogeny in fossil Helicoprion. Biology Letters. 10.1098/rsbl.2013.0057 The family disappeared in the Early Triassic The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ornithoprion
''Ornithoprion'' is an extinct genus of eugeneodont holocephalan closely related to '' Caseodus.'' It lived in the Moscovian Moscovian may refer to: *An inhabitant of Moscow, the capital of Russia *Something of, from, or related to Moscow *Moscovian (Carboniferous) The Moscovian is in the International Commission on Stratigraphy, ICS geologic timescale a stage (strati ... stage of the Carboniferous from 315.2 to 307 million years ago. Various species had an elongated lower jaw. The discovery and description of ''Ornithoprion'' helped establish many aspects of eugeneodont skull anatomy, which previously could only be gleaned from tooth data. References Carboniferous fish of North America Carboniferous cartilaginous fish Prehistoric cartilaginous fish genera {{Paleo-cartilaginous-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
