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Megamouth Shark
The megamouth shark (''Megachasma pelagios'') is a species of deepwater shark. It is rarely seen by humans and is the smallest of the three extant taxon, extant filter-feeding sharks alongside the relatively larger whale shark and basking shark. Since its discovery in 1976, fewer than 100 specimens have been observed or caught. Like the other two Planktivore, planktivorous sharks, it swims with its mouth wide open, filtering water for plankton and jellyfish. It is recognizable from its large head with rubbery lips. The megamouth is so unlike any other type of shark that it is usually considered to be the sole extant species in the family Megachasmidae, though some scientists have suggested it may belong in the family Cetorhinidae. Description The appearance of the megamouth is distinctive, but little else is known about it. It has a brownish-black colour on top, is white underneath, and has an asymmetrical tail with a long upper lobe, similar to that of the thresher shark. The i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megachasma Pelagios
The megamouth shark (''Megachasma pelagios'') is a species of deepwater shark. It is rarely seen by humans and is the smallest of the three extant filter-feeding sharks alongside the relatively larger whale shark and basking shark. Since its discovery in 1976, fewer than 100 specimens have been observed or caught. Like the other two planktivorous sharks, it swims with its mouth wide open, filtering water for plankton and jellyfish. It is recognizable from its large head with rubbery lips. The megamouth is so unlike any other type of shark that it is usually considered to be the sole extant species in the family Megachasmidae, though some scientists have suggested it may belong in the family Cetorhinidae. Description The appearance of the megamouth is distinctive, but little else is known about it. It has a brownish-black colour on top, is white underneath, and has an asymmetrical tail with a long upper lobe, similar to that of the thresher shark. The interior of its gill slits a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megachasma Applegatei
''Megachasma applegatei'' is an extinct species of megamouth shark from the Oligocene to early Miocene (28-23 Mya) of the Western United States. The type fossil was discovered in the San Joaquin Valley The San Joaquin Valley ( ; es, Valle de San Joaquín) is the area of the Central Valley of the U.S. state of California that lies south of the Sacramento–San Joaquin River Delta and is drained by the San Joaquin River. It comprises seven c ... in 1973, but only described in 2014, when the species was named after its discoverer, Shelton Applegate. Description ''Magachasma applegatei'' was described from a single tooth. Based on comparison with the teeth of the recent species (''Megachasma pelagios''), it was approximately 6 m long and, like modern megamouth sharks, probably fed on fish and small planktonic invertebrates both in deep and shallow water habitats. Its teeth had shorter crowns and a pair of side cusplets. References Megachasmidae Prehistoric sharks Fossi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megamouth Shark Japan2
The megamouth shark (''Megachasma pelagios'') is a species of deepwater shark. It is rarely seen by humans and is the smallest of the three extant filter-feeding sharks alongside the relatively larger whale shark and basking shark. Since its discovery in 1976, fewer than 100 specimens have been observed or caught. Like the other two planktivorous sharks, it swims with its mouth wide open, filtering water for plankton and jellyfish. It is recognizable from its large head with rubbery lips. The megamouth is so unlike any other type of shark that it is usually considered to be the sole extant species in the family Megachasmidae, though some scientists have suggested it may belong in the family Cetorhinidae. Description The appearance of the megamouth is distinctive, but little else is known about it. It has a brownish-black colour on top, is white underneath, and has an asymmetrical tail with a long upper lobe, similar to that of the thresher shark. The interior of its gill slits a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toba Aquarium
is a public aquarium, which is located in Toba, Mie, Japan. The aquarium houses 12 zones which reproduce natural environments, housing some 25,000 individuals representing 1,200 species. The guests are free to tour the aquarium's grounds in any manner they please, as there is no fixed route. The total length of the aisle is about 1.5 kilometers. History Toba Aquarium opened May 1955. It was founded by Haruaki Nakamura(中村幸昭), now the honorary president. It has received more than 50 million visitors, making it one of the most visited locations in Japan. The aquarium hosts scholarly investigations as an adult education institution in conjunction with the Ministry of Education, Culture, Sports, Science and Technology officially specifying the Toba Aquarium as a museum. Toba Aquarium also emphasizes protection and breeding of rare marine creatures which are in danger of extinction. Notable breeding events include the birth of a finless porpoise, a birth of the second genera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caudal Keel
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 lure ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dana Point, California
Dana Point () is a city located in southern Orange County, California, United States. The population was 33,107 at the 2020 census. It has one of the few harbors along the Orange County coast, and with ready access via State Route 1, it is a popular local destination for surfing. The city was named after the headland of Dana Point, which was in turn named after Richard Henry Dana, Jr., author of ''Two Years Before the Mast'', which included a description of the area. Dana described the locale, including neighboring San Juan Capistrano, as "the only romantic spot on the coast". This area is designated California Historical Landmark #189. History Dana Point was a popular port for ships involved with the hide trade with nearby Mission San Juan Capistrano. Trading reached its peak in the 1830s and 1840s. In 1818, Argentine sailor Hippolyte de Bouchard anchored there while conducting his raid on the mission. Richard Henry Dana then visited the area in 1835 while serving aboard t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Convergent Evolution
Convergent evolution is the independent evolution of similar features in species of different periods or epochs in time. Convergent evolution creates analogous structures that have similar form or function but were not present in the last common ancestor of those groups. The cladistic term for the same phenomenon is homoplasy. The recurrent evolution of flight is a classic example, as flying insects, birds, pterosaurs, and bats have independently evolved the useful capacity of flight. Functionally similar features that have arisen through convergent evolution are ''analogous'', whereas '' homologous'' structures or traits have a common origin but can have dissimilar functions. Bird, bat, and pterosaur wings are analogous structures, but their forelimbs are homologous, sharing an ancestral state despite serving different functions. The opposite of convergence is divergent evolution, where related species evolve different traits. Convergent evolution is similar to parallel evo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudomegachasma
''Pseudomegachasma'' ("false Megamouth shark, megamouth") is an extinct genus of Filter feeder, filter-feeding shark that was closely related to the modern sand tiger shark. It is known from Cretaceous strata in Russia and the United States, and is the only known Planktivore, planktivorous Odontaspididae, odontaspid, as well as the oldest known planktivorous Elasmobranchii, elasmobranch. It most likely derived from its closest relative, the Piscivore, piscivorous shark ''Johnlongia''. As its name suggests, it was originally classified under ''Megachasma'', before it was found to be an odontaspid. References Odontaspididae Cretaceous sharks Cenomanian life Cretaceous Russia Fossils of Russia Cretaceous fish of North America Fossils of the United States Fossil taxa described in 2015 {{shark-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Miocene
The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recent" because it has 18% fewer modern marine invertebrates than the Pliocene has. The Miocene is preceded by the Oligocene and is followed by the Pliocene. As Earth went from the Oligocene through the Miocene and into the Pliocene, the climate slowly cooled towards a series of ice ages. The Miocene boundaries are not marked by a single distinct global event but consist rather of regionally defined boundaries between the warmer Oligocene and the cooler Pliocene Epoch. During the Early Miocene, the Arabian Peninsula collided with Eurasia, severing the connection between the Mediterranean and Indian Ocean, and allowing a faunal interchange to occur between Eurasia and Africa, including the dispersal of proboscideans into Eurasia. During the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oligocene
The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the exact dates of the start and end of the epoch are slightly uncertain. The name Oligocene was coined in 1854 by the German paleontologist Heinrich Ernst Beyrich from his studies of marine beds in Belgium and Germany. The name comes from the Ancient Greek (''olígos'', "few") and (''kainós'', "new"), and refers to the sparsity of extant forms of molluscs. The Oligocene is preceded by the Eocene Epoch and is followed by the Miocene Epoch. The Oligocene is the third and final epoch of the Paleogene Period. The Oligocene is often considered an important time of transition, a link between the archaic world of the tropical Eocene and the more modern ecosystems of the Miocene. Major changes during the Oligocene included a global expansion o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megachasma Alisonae
''Megachasma alisonae'' is an extinct species of megamouth shark that lived during the Eocene (Priabonian, ca. 36 mya). It is the oldest fossil record of a megamouth shark. The type fossil was recovered from the Søvind Marl Formation in Denmark and consists of a single tooth. Based on comparison with the teeth of the recent megamouth species (''Megachasma pelagios''), the length of the animal has been estimated at . Discovery and naming The holotype and only known specimen of ''M. alisonae'' is NHMUK PV P73711, an isolated tooth. It is nearly complete and either belonged to the right side of the upper jaw or the left side of the lower jaw. It was discovered on a sea cliff in the Pyt Member of the Søvind Marl Formation in Denmark. The tooth was discovered in a bulk sediment sample from the upper of the member that was collected in 1988. The species was described by Kenshu Shimada and David J. Ward in 2016. The specific name honors Alison Ward, who aided David J. Ward with t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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