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Antineosteus
''Antineosteus'' is an extinct genus of homostiid arthrodire from the Emsian, Early Devonian Kess-Kess Mounds, in the eastern Anti-Atlas Mountains, Morocco, and the Barrandian area of the Czech Republic. Description ''Antineosteus lehmani'' is rather fragmentary, known from a left anterior dorsolateral plate, a left paranuchal plate, and an inferognathal. ''A. rufus'' is known from a nearly-complete right head shield plate, and a right anterior dorsolateral plate. ''A. rufus'' is estimated to exceed , from measuring the plates with the ones from better-preserved, related taxa. Diet ''Antineosteus'', like many other members of Homostiidae, lacked bladed dentition on their jaws, and was large in size. These traits all in one animal support a planktivorous lifestyle, like baleen whales, or the whale shark, as supported by Denison, 1978, suggesting similar lifestyles for arthrodires like ''Homostius'', making it reasonable for many homostiids to be suspension-feeders like th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homostiidae
Homostiidae is a family of flattened arthrodire placoderms from the Early to Middle Devonian. Fossils appear in various strata in Europe, Russia, Morocco, Australia, Canada and Greenland. Many homostiids have " toothless" jaws, and large sizes. suggesting that many homostiids were probably filter feeders, like the also noticeably flattened Rhincodon typus. All homostiids have flattened and elongated skulls. According to Denison 1978, primitive homostiids have moderately long median dorsal plates, whereas in "advanced" homostiids, the median dorsal tends to be short and broad. Obruchev (1964) placed the following primitive genera ''Euleptaspis'', ''Lophostracon'' and ''Luetkeichthys'' in a separate family, "Euleptaspididae," and Ørvig (1969), claimed that the Euleptaspidids were totally unrelated to Homostiidae proper (i.e., being neither related to, nor ancestral), but, according to Denison, did not clearly explain his reasons why this was so. Genera ''Angarichthys'' A comp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tityosteus
''Tityosteus'' is an extinct genus of homostiid arthrodire from the Early Emsian of the Early Devonian, with fossils known from Germany, the Ibero-Armorican Trough, and southern Siberia. Description ''Tityosteus'' has only an 11 cm right marginal plate known, and margin ends and parts, in addition to the central plate overlap area being broken. According to "Tityosteus, A MARINE FISH (ARTHRODIRA, HOMOSTIIDAE) FROM THE EMSIAN OF ARAGÓN, SPAIN, AND ITS DISTRIBUTION", given Tityosteus's distribution, and Carolowilhelma (a pelagic arthrodire), being from similar facies as Tityosteus (Eifelian of Aragón, Spain), it may have been pelagic, and able to cross open waters. Diet While the inferognathals of ''Tityosteus'' have not been found, they could be either "toothless", like '' Homosteus'', which has been suggested to be planktivorous, or possessing fine denticles, like ''Antineosteus''. It has been suggested that ''Tityosteus'' probably was similar to the whale shark ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placoderms Of Africa
Placodermi (from Greek πλάξ 'plate' and δέρμα 'skin', literally ' plate-skinned') is a class of armoured prehistoric fish, known from fossils, which lived from the Silurian to the end of the Devonian period. Their head and thorax were covered by articulated armoured plates and the rest of the body was scaled or naked, depending on the species. Placoderms were among the first jawed fish; their jaws likely evolved from the first of their gill arches. Placoderms are thought to be paraphyletic, consisting of several distinct outgroups or sister taxa to all living jawed vertebrates, which originated among their ranks. In contrast, one 2016 analysis concluded that placodermi are likely monophyletic, though these analyses have been further dismissed with more transitional taxa between placoderms and modern gnathosthomes, solidifying their paraphyletic status. Placoderms were also the first fish to develop pelvic fins, the precursor to hindlimbs in tetrapods, as well as tru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arthrodira
Arthrodira (Greek for "jointed neck") is an order of extinct armored, jawed fishes of the class Placodermi that flourished in the Devonian period before their sudden extinction, surviving for about 50 million years and penetrating most marine ecological niches. Arthrodires were the largest and most diverse of all groups of Placoderms. Description Arthrodire placoderms are notable for the movable joint between armor surrounding their heads and bodies. Like all placoderms, they lacked distinct teeth; instead, they used the sharpened edges of a bony plate on their jawbone as a biting surface. The eye sockets are protected by a bony ring, a feature shared by birds and some ichthyosaurs. Early arthrodires, such as the genus '' Arctolepis'', were well-armoured fishes with flattened bodies. The largest member of this group, '' Dunkleosteus'', was a true superpredator of the latest Devonian period, reaching as much as 6 m in length. In contrast, the long-nosed '' Rolfosteus'' measured j ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homosteus
''Homosteus'' is a genus of flattened arthrodire placoderm from the Middle Devonian. Fossils are found primarily in Eifelian-epoch aged strata of Europe, Canada, Greenland, and Estonia. All of the species had comparatively large, flattened heads with, as suggested by the upward opening orbits, upward-pointing eyes. These adaptations suggest that the various species were benthic predators. A study on '' Titanichthys'', in contrast, suggests that species of ''Homosteus'' may have been filter-feeders instead. ''Homosteus'' specimens from the Old Red Sandstone of Scotland are known to be significantly radioactive, on the order of 1.2 * 104 gamma/min/g ic Notably, ''Homosteus'' specimens are the only fish fossils from the Old Red Sandstone to show significant radioactivity. This suggests that these specimens became radioactive from the animals ingesting radioactive isotopes in life (e.g., through ingesting radioactive sediment), rather than radioactive isotopes being absorbed by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homostius
''Homosteus'' is a genus of flattened arthrodire placoderm from the Middle Devonian. Fossils are found primarily in Eifelian-epoch aged strata of Europe, Canada, Greenland, and Estonia. All of the species had comparatively large, flattened heads with, as suggested by the upward opening orbits, upward-pointing eyes. These adaptations suggest that the various species were benthic predators. A study on ''Titanichthys'', in contrast, suggests that species of ''Homosteus'' may have been filter-feeders instead. ''Homosteus'' specimens from the Old Red Sandstone of Scotland are known to be significantly radioactive, on the order of 1.2 * 104 gamma/min/g ic Notably, ''Homosteus'' specimens are the only fish fossils from the Old Red Sandstone to show significant radioactivity. This suggests that these specimens became radioactive from the animals ingesting radioactive isotopes in life (e.g., through ingesting radioactive sediment), rather than radioactive isotopes being absorbed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taemasosteus
''Taemasosteus'' is an extinct genus of arthrodire placoderm. Its fossils have been found in Emsian-aged marine strata in New South Wales, Australia. It contains two species, ''T. novaustrocambricus'', and ''T. maclartiensis''. The genus (and a monotypic family, "Taemasosteidae") was originally erected on the basis of "an imperfect" paranuchal, though, more specimens were found, eventually leading "Taemasosteidae" to be subsumed into Buchanosteidae. Even so, the reconstructed anatomy leads some researchers to conclude that ''Taemasosteus'' is close to the ancestry of Homostiidae. These researchers place ''Taemasosteus'' as the sister taxon of Homostiidae (or a select group of the better known homostiid genera) within the taxon In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanichthys
''Titanichthys'' is an extinct genus of giant, aberrant marine placoderm from shallow seas of the Late Devonian of Morocco, Eastern North America, and possibly Europe. Many of the species approached '' Dunkleosteus'' in size and build. Unlike its relative, however, the various species of ''Titanichys'' had small, ineffective-looking mouth-plates that lacked a sharp cutting edge. It is assumed that ''Titanichthys'' was a filter feeder that used its capacious mouth to swallow or inhale schools of small, anchovy-like fish, or possibly krill-like zooplankton, and that the mouth-plates retained the prey while allowing the water to escape as it closed its mouth. A study has since confirmed this assumption as its jaws are functionally closer to that of filter feeders like baleen whales and basking sharks, and it appears to have developed from benthic durophagists that became pelagic suspension feeders. This would make it the first (known) large-sized vertebrate filter feeder. ''Titani ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suspension Feeder
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 resul ... [...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, dod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whale Shark
The whale shark (''Rhincodon typus'') is a slow-moving, filter-feeding carpet shark and the largest known extant fish species. The largest confirmed individual had a length of .McClain CR, Balk MA, Benfield MC, Branch TA, Chen C, Cosgrove J, Dove ADM, Gaskins LC, Helm RR, Hochberg FG, Lee FB, Marshall A, McMurray SE, Schanche C, Stone SN, Thaler AD. 2015. "Sizing ocean giants: patterns of intraspecific size variation in marine megafauna". ''PeerJ'' 3:e715 . The whale shark holds many records for size in the animal kingdom, most notably being by far the largest living nonmammalian vertebrate. It is the sole member of the genus ''Rhincodon'' and the only extant member of the family Rhincodontidae, which belongs to the subclass Elasmobranchii in the class Chondrichthyes. Before 1984 it was classified as ''Rhiniodon'' into Rhinodontidae. The whale shark is found in open waters of the tropical oceans and is rarely found in water below . Studies looking at vertebral growth bands an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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