Megalodon
''Otodus megalodon'' ( ; meaning "big tooth"), Common name, commonly known as megalodon, is an extinction, extinct species of giant mackerel shark that lived approximately 23 to 3.6 million years ago (Mya), from the Early Miocene to the Early Pliocene epochs. ''O. megalodon'' was formerly thought to be a member of the family (biology), family Lamnidae and a close relative of the great white shark (''Carcharodon carcharias''), but has been reclassified into the extinct family Otodontidae, which Speciation, diverged from the great white shark during the Early Cretaceous. While regarded as one of the largest and most powerful predators to have ever lived, megalodon is only known from fragmentary remains, and its appearance and maximum size are uncertain. Scientists have argued whether its body form was more stocky or elongated than the modern lamniform sharks. Maximum body length estimates between based on various analyses have been proposed, though the Mode (statistics), modal ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Livyatan
''Livyatan'' is an extinct genus of macroraptorial Physeteroidea, sperm whale containing one known species: ''L. melvillei''. The genus name was inspired by the Bible, biblical sea monster Leviathan, and the species name by Herman Melville, the author of the famous novel ''Moby-Dick'' about a white bull sperm whale. Herman Melville often referred to whales as "Leviathans" in his book. It is mainly known from the Pisco Formation of Peru during the Tortonian stage of the Miocene Epoch (geology), epoch, about 9.9–8.9 million years ago (mya); however, finds of isolated teeth from other locations such as Chile, Argentina, the United States (California), South Africa and Australia imply that either it or a close relative survived into the Pliocene, around 5mya, and may have had a global presence. It was a member of a group of macroraptorial sperm whales (or "raptorial sperm whales") and was probably an apex predator, preying on whales, seals and so forth. Characteristically of rapto ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Mackerel Shark
The Lamniformes (, from Greek ''lamna'' "fish of prey") are an order of sharks commonly known as mackerel sharks (which may also refer specifically to the family Lamnidae). It includes some of the most familiar species of sharks, such as the great white as well as less familiar ones, such as the goblin shark and megamouth shark. Members of the order are distinguished by possessing two dorsal fins, an anal fin, five gill slits, eyes without nictitating membranes, and a mouth extending behind the eyes. Species in two families of Lamniformes – Lamnidae and Alopiidae – are distinguished for maintaining a higher body temperature than the surrounding waters. Members of the group include macropredators, generally of medium-large size, including the largest macropredatory shark ever, the extinct '' Otodus megalodon,'' as well as large planktivores. Although some authors have argued that the Late Jurassic '' Palaeocarcharias'' should be considered the oldest known lamniform, ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Marine Life
Marine life, sea life or ocean life is the collective ecological communities that encompass all aquatic animals, aquatic plant, plants, algae, marine fungi, fungi, marine protists, protists, single-celled marine microorganisms, microorganisms and associated marine virus, viruses living in the saline water of marine habitats, either the sea water of marginal seas and oceans, or the brackish water of coastal wetlands, lagoons, estuary, estuaries and inland seas. , more than 242,000 marine species have been documented, and perhaps two million marine species are yet to be documented. An average of 2,332 new species per year are being described. Marine life is studied scientifically in both marine biology and in biological oceanography. By volume, oceans provide about 90% of the living space on Earth, and served as the cradle of life and vital biotic sanctuaries throughout Earth's geological history. The earliest known life forms evolved as anaerobe, anaerobic prokaryotes (archaea ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Lamniform
The Lamniformes (, from Greek ''lamna'' "fish of prey") are an order of sharks commonly known as mackerel sharks (which may also refer specifically to the family Lamnidae). It includes some of the most familiar species of sharks, such as the great white as well as less familiar ones, such as the goblin shark and megamouth shark. Members of the order are distinguished by possessing two dorsal fins, an anal fin, five gill slits, eyes without nictitating membranes, and a mouth extending behind the eyes. Species in two families of Lamniformes – Lamnidae and Alopiidae – are distinguished for maintaining a higher body temperature than the surrounding waters. Members of the group include macropredators, generally of medium-large size, including the largest macropredatory shark ever, the extinct '' Otodus megalodon,'' as well as large planktivores. Although some authors have argued that the Late Jurassic '' Palaeocarcharias'' should be considered the oldest known lamniform, ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Baleen Whale
Baleen whales (), also known as whalebone whales, are marine mammals of the order (biology), parvorder Mysticeti in the infraorder Cetacea (whales, dolphins and porpoises), which use baleen plates (or "whalebone") in their mouths to sieve plankton from the water. Mysticeti comprises the family (biology), families Balaenidae (right whale, right and Bowhead whale, bowhead whales), Balaenopteridae (rorquals), Eschrichtiidae (the gray whale) and Cetotheriidae (the pygmy right whale). There are currently 16 species of baleen whales. While cetaceans were historically thought to have descended from Mesonychia, mesonychians, molecular phylogenetics, molecular evidence instead supports them as a clade of even-toed ungulates (Artiodactyla). Baleen whales split from toothed whales (Odontoceti) around 34 mya (unit), million years ago. Baleen whales range in size from the and pygmy right whale to the and blue whale, the Largest organisms, largest known animal to have ever existed. They ar ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Otodontidae
Otodontidae is an extinct family of sharks belonging to the order Lamniformes. Its members have been described as megatoothed sharks. They lived from the Early Cretaceous to the Pliocene, and included genera such as '' Otodus,'' including the giant megalodon ''Otodus megalodon'' ( ; meaning "big tooth"), Common name, commonly known as megalodon, is an extinction, extinct species of giant mackerel shark that lived approximately 23 to 3.6 million years ago (Mya), from the Early Miocene to the Earl .... Recent studies of the newly described genus '' Megalolamna'' indicate that the members of the genus ''Carcharocles'' should be reclassified as members of the genus ''Otodus''. The genus '' Cretalamna'' which lived from the mid-Cretaceous-Paleogene is believed to be directly ancestral to ''Otodus,'' and thus to megalodon. There are certain dubious species of ''Otodontidae'' included species where teeth are not properly described, such as '' Otodus debrayi'', '' Otodus stromeri ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Whales
Whales are a widely distributed and diverse group of fully Aquatic animal, aquatic placental mammal, placental marine mammals. As an informal and Colloquialism, colloquial grouping, they correspond to large members of the infraorder Cetacea, i.e. all cetaceans apart from dolphins and porpoises. Dolphins and porpoises may be considered whales from a formal, Cladistics, cladistic perspective. Whales, dolphins and porpoises belong to the order Cetartiodactyla, which consists of even-toed ungulates. Their closest non-cetacean living relatives are the hippopotamuses, from which they and other cetaceans diverged about 54 million years ago. The two parvorders of whales, baleen whales (Mysticeti) and toothed whales (Odontoceti), are thought to have had their Most recent common ancestor, last common ancestor around 34 million years ago. Mysticetes include four Neontology, extant (living) Family (biology), families: Balaenopteridae (the rorquals), Balaenidae (right whales), Cetotheriid ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Teeth
A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tearing food, for defensive purposes, to intimidate other animals often including their own, or to carry prey or their young. The roots of teeth are covered by gums. Teeth are not made of bone, but rather of multiple tissues of varying density and hardness that originate from the outermost embryonic germ layer, the ectoderm. The general structure of teeth is similar across the vertebrates, although there is considerable variation in their form and position. The teeth of mammals have deep roots, and this pattern is also found in some fish, and in crocodilians. In most teleost fish, however, the teeth are attached to the outer surface of the bone, while in lizards they are attached to the inner surface of the jaw by one side. In cartilaginous ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Cosmopolitan Distribution
In biogeography, a cosmopolitan distribution is the range of a taxon that extends across most or all of the surface of the Earth, in appropriate habitats; most cosmopolitan species are known to be highly adaptable to a range of climatic and environmental conditions, though this is not always so. Killer whales ( orcas) are among the most well-known cosmopolitan species on the planet, as they maintain several different resident and transient (migratory) populations in every major oceanic body on Earth, from the Arctic Circle to Antarctica and every coastal and open-water region in-between. Such a taxon (usually a species) is said to have a ''cosmopolitan'' distribution, or exhibit cosmopolitanism, as a species; another example, the rock dove (commonly referred to as a ' pigeon'), in addition to having been bred domestically for centuries, now occurs in most urban areas around the world. The extreme opposite of a cosmopolitan species is an endemic (native) species, or one foun ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Early Miocene
The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene epoch (geology), Epoch made up of two faunal stage, stages: the Aquitanian age, Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 annum, Ma to 15.97 ± 0.05 Ma (million years ago). It was preceded by the Oligocene epoch. As the climate started to get cooler, the landscape started to change. New mammals evolved to replace the extinct animals of the Oligocene epoch. The first members of the hyena and weasel family started to evolve to replace the extinct ''Hyaenodon'', entelodonts and bear-dogs. The chalicotheres survived the Oligocene epoch. A new genus of entelodont called ''Daeodon'' evolved in order to adapt to the new habitats and hunt the new prey animals of the Early Miocene epoch; it quickly became the top predator of North America. But it became extinct due to competition from ''Amphicyon'', a newcomer from Eurasia. ''Amphicyon'' bested ''Daeodon'' because the bear-dog's la ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Pinniped
Pinnipeds (pronounced ), commonly known as seals, are a widely range (biology), distributed and diverse clade of carnivorous, fin-footed, semiaquatic, mostly marine mammals. They comprise the extant taxon, extant families Odobenidae (whose only living member is the walrus), Otariidae (the eared seals: sea lions and fur seals), and Phocidae (the earless seals, or true seals), with 34 extant species and more than 50 extinct species described from fossils. While seals were historically thought to have descended from two ancestral lines, molecular phylogenetics, molecular evidence supports them as a monophyletic group (descended from one ancestor). Pinnipeds belong to the suborder Caniformia of the order Carnivora; their closest living relatives are musteloids (Mustelidae, weasels, Procyonidae, raccoons, skunks and red pandas), having diverged about 50 million years ago. Seals range in size from the and Baikal seal to the and southern elephant seal. Several species exhibit ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |
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Sea Turtle
Sea turtles (superfamily Chelonioidea), sometimes called marine turtles, are reptiles of the order Testudines and of the suborder Cryptodira. The seven existing species of sea turtles are the flatback, green, hawksbill, leatherback, loggerhead, Kemp's ridley, and olive ridley. Six of the seven sea turtle species, all but the flatback, are present in U.S. waters, and are listed as endangered and/or threatened under the Endangered Species Act. They are listed as threatened with extinction globally on the IUCN Red List of Threatened Species. The flatback turtle is found only in the waters of Australia, Papua New Guinea, and Indonesia. Sea turtles can be categorized as hard-shelled ( cheloniid) or leathery-shelled ( dermochelyid).Wyneken, J. 2001. The Anatomy of Sea Turtles. U.S Department of Commerce NOAA Technical Memorandum NMFS-SEFSC-470, 1-172 pp. The only dermochelyid species of sea turtle is the leatherback. Description For each of the seven species of sea turtles, ... [...More Info...]       [...Related Items...]     OR:     [Wikipedia]   [Google]   [Baidu]   |