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Ctenacanth
Ctenacanthiformes is an extinct order of chondrichthyan fish. They possessed ornamented fin spines and cladodont dentition. Members of the family Ctenacanthidae may have survived into the Cretaceous based on teeth found in deep water deposits of Valanginian In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 139.8 ± 3.0 Ma and 132.9 ± 2.0 Ma (million years ago). The Valanginian Stage succeeds the Berriasian Stage of the Lower Cretaceou ... age in France and Austria. References Prehistoric cartilaginous fish orders {{Paleo-cartilaginous-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ctenacanthidae
Ctenacanthidae is an extinct family of prehistoric sharks in the order Ctenacanthiformes. Species of the different genera are found in strata ranging from Devonian to Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ..., with a worldwide distribution. References External links * * Prehistoric cartilaginous fish families {{Paleo-cartilaginous-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ctenacanth
Ctenacanthiformes is an extinct order of chondrichthyan fish. They possessed ornamented fin spines and cladodont dentition. Members of the family Ctenacanthidae may have survived into the Cretaceous based on teeth found in deep water deposits of Valanginian In the geologic timescale, the Valanginian is an age or stage of the Early or Lower Cretaceous. It spans between 139.8 ± 3.0 Ma and 132.9 ± 2.0 Ma (million years ago). The Valanginian Stage succeeds the Berriasian Stage of the Lower Cretaceou ... age in France and Austria. References Prehistoric cartilaginous fish orders {{Paleo-cartilaginous-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ctenacanthoidea
Ctenacanthoidea is an extinct superfamily of prehistoric Elasmobranchs. These nectonic carnivores first appeared around 407 million years ago, during the Devonian, and survived until the early Cretaceous. A Miocene record, ''Wodnika ocoyae'', is now considered a concretion A concretion is a hard, compact mass of matter formed by the precipitation of mineral cement within the spaces between particles, and is found in sedimentary rock or soil. Concretions are often ovoid or spherical in shape, although irregular .... Fossils belonging to this group have been found worldwide. References Prehistoric cartilaginous fish taxa {{Paleo-cartilaginous-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chondrichthyan
Chondrichthyes (; ) is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fishes'', which have skeletons primarily composed of bone tissue. Chondrichthyes are jawed vertebrates with paired fins, paired nares, scales, and a heart with its chambers in series. Extant chondrichthyes range in size from the 10 cm (3.9 in) finless sleeper ray to the 10 m (32 ft) whale shark. The class is divided into two subclasses: Elasmobranchii (sharks, rays, skates, and sawfish) and Holocephali ( chimaeras, sometimes called ghost sharks, which are sometimes separated into their own class). Within the infraphylum Gnathostomata, cartilaginous fishes are distinct from all other jawed vertebrates. Anatomy Skeleton The skeleton is cartilaginous. The notochord is gradually replaced by a vertebral column during development, except in Holocephali, where the notochord stays intact. In some deepwater ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chondrichthyes
Chondrichthyes (; ) is a class that contains the cartilaginous fishes that have skeletons primarily composed of cartilage. They can be contrasted with the Osteichthyes or ''bony fishes'', which have skeletons primarily composed of bone tissue. Chondrichthyes are jawed vertebrates with paired fins, paired nares, scales, and a heart with its chambers in series. Extant chondrichthyes range in size from the 10 cm (3.9 in) finless sleeper ray to the 10 m (32 ft) whale shark. The class is divided into two subclasses: Elasmobranchii (sharks, rays, skates, and sawfish) and Holocephali ( chimaeras, sometimes called ghost sharks, which are sometimes separated into their own class). Within the infraphylum Gnathostomata, cartilaginous fishes are distinct from all other jawed vertebrates. Anatomy Skeleton The skeleton is cartilaginous. The notochord is gradually replaced by a vertebral column during development, except in Holocephali, where the notochord stays intact. In some deepwat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kaibabvenator
''Kaibabvenator swiftae'' is a very large, extinct ctenacanthiform shark that lived in marine environments in what is now Arizona, during the Middle Permian Period. ''K. swiftae'' is known from large teeth up to 30 millimeters long found in the Kachina Microsite, of the lower Fossil Mountain Member, in the Kaibab Formation near Flagstaff, Arizona. The specific name honors researcher Sandra Swift for her paleontological contributions to Northern Arizona University Northern Arizona University (NAU) is a public research university based in Flagstaff, Arizona. It was founded in 1899 as the final public university established in the Arizona Territory, 13 years before Arizona was admitted as the 48th state. .... References Permian fish of North America Fish enigmatic taxa Monotypic prehistoric animal genera {{Paleo-cartilaginous-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holdenius
''Holdenius'' is an extinct genus of arthrodire placoderm fish which lived during the Late Devonian period. Description ''Holdenius'' was a large arthrodire, reaching lengths of around . This placoderm is known only from isolated jaw bones, and little is known about it except that it is relatively morphologically similar to its more famous relative ''Dunkleosteus'', with which it shared a spatial and temporal range. ''Holdenius'' was a piscivorous animal that used its sharp shearing gnathal plates to seize and cleave its prey into manageable pieces. One articulated specimen of this placoderm from the Upper Devonian Cleveland Shale was preserved adjacent to the remains of its prey; a ''Ctenacanth'' chondrichthyan, which had been bitten in half. Considering its prey was over half its size, it can be inferred that ''Holdenius'' was an exceptionally aggressive nektonic predator. An anterior dorsal spine from the ctenacanth was found lodged in the palate and extending into the bra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Goodrichthys
''Goodrichthys'' is a Carboniferous genus of 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 Selachimo ... from the Glencartholm Volcanic Beds Formation ( Upper Border Group) of Scotland. References Prehistoric cartilaginous fish genera Carboniferous sharks {{Paleo-cartilaginous-fish-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cladodont
This is a typical Cladodont tooth, of a shark called ''Glikmanius''">Glikmanius.html" ;"title="shark called ''Glikmanius">shark called ''Glikmanius'' Cladodont (from Latin cladus, meaning branch and Greek Odon, meaning tooth) is the term for a common category of early Devonian shark known primarily for its "multi-cusped" tooth consisting of one long blade surrounded by many short, fork-like tines, designed to catch food that was swallowed whole, instead of being used to saw off chunks of meat like many modern sharks. The skinny teeth would puncture and grasp the prey, keeping it from wriggling free. Because the most common fossil evidence of cartilaginous fish is teeth, this term is also used for the fossilised teeth themselves. History The fossil tooth of '' Cladodus belifer'', which lived about 260,000,000 years ago in what would someday be Illinois. The roundness of the main tooth, and the small tines around it, show it to be a cladodont. The earliest known shark, ''Clado ... [...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] |
Extinction
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. More than 99% of all species that ever lived on Earth, amounting to over five billion species, are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryote globally, and possibly many times more if microorganisms, like bacteria, are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, dodos, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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