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Sirenians
The Sirenia (), commonly referred to as sea-cows or sirenians, are an order (biology), order of fully aquatic, herbivorous mammals that inhabit swamps, rivers, estuaries, marine wetlands, and coastal marine waters. The Sirenia currently comprise two distinct family (biology), families: Dugongidae (the dugong and the now extinct Steller's sea cow) and Trichechidae (manatees, namely the Amazonian manatee, West Indian manatee, and West African manatee) with a total of four species. The Protosirenidae (Eocene sirenians) and Prorastomidae (terrestrial sirenians) families are extinct. Sirenians are classified in the clade Paenungulata, alongside the elephants and the hyraxes, and evolved in the Eocene 50 million years ago (mya). The Dugongidae Genetic divergence, diverged from the Trichechidae in the late Eocene or early Oligocene (30–35 mya). Sirenians grow to between in length and in weight. The historic Steller's sea cow was the largest known sirenian to have lived, and could r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prorastomidae
Prorastomidae is a family of extinct sirenians from Jamaica, related to the extant manatees and dugong. The family includes the oldest known fossils of Sirenians, represented in two genera: *''Pezosiren'' ''Pezosiren'' comprises one known species, ''Pezosiren portelli'', that was discovered in modern-day Jamaica. One of the earliest true Sirenian species, ''P. portelli'' is distinct from extant Sirenians due to its quadrupedal stature. The species is estimated to have lived 50 million years ago during the Mid Eocene, and the skeletal elements suggest that ''P. portelli'' was able to properly support its body weight while out of the water. However, several morphological features suggest that this species spent significant amounts of time in an aquatic environment, such as ''P. portellis pachyosteosclerotic ribs. Similar to an extant manatee's ribs, these ribs provided a ballast and allowed the animal to achieve neutral buoyancy. ''P. portelli'' lacked the large, muscular tail used i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
West Indian Manatee
The West Indian manatee (''Trichechus manatus''), also known as the North American manatee, is a large, aquatic mammal native to warm coastal areas of the Caribbean, from the eastern US to northern Brazil. Living alone or in herds, it feeds on underwater plants and uses its whiskers to navigate. It is divided into two endangered subspecies, the Florida manatee (''T. m. latirostris'') in the US and the Antillean manatee (''T. m. manatus'') in the Caribbean, both of which face pressure from habitat loss, pollution, and other human activity. The West Indian manatee is the largest of the sirenians (order Sirenia), a group of large aquatic mammals that includes the dugong, other manatees, and the extinct Steller's sea cow. Manatees are herbivores, have developed vocal communication abilities, and are covered in highly sensitive whiskers (called vibrissae) that are used for feeding and navigation. In breeding season, several males form mating herds around an individual female; on aver ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Steller's Sea Cow
Steller's sea cow (''Hydrodamalis gigas'') is an extinct sirenian described by Georg Wilhelm Steller in 1741. At that time, it was found only around the Commander Islands in the Bering Sea between Alaska and Russia; its range extended across the North Pacific during the Pleistocene epoch, and likely contracted to such an extreme degree due to the glacial cycle. It is possible indigenous populations interacted with the animal before Europeans. Steller first encountered it on Vitus Bering's Great Northern Expedition when the crew became shipwrecked on Bering Island. Much of what is known about its behavior comes from Steller's observations on the island, documented in his posthumous publication ''On the Beasts of the Sea''. Within 27 years of its discovery by Europeans, the slow-moving and easily-caught mammal was hunted into extinction for its meat, fat, and hide. Some 18th-century adults would have reached weights of and lengths up to . It was a member of the family Dugongida ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dugong
The dugong (; ''Dugong dugon'') is a marine mammal. It is one of four living species of the order Sirenia, which also includes three species of manatees. It is the only living representative of the once-diverse family Dugongidae; its closest modern relative, Steller's sea cow (''Hydrodamalis gigas''), was hunted to extinction in the 18th century. The dugong is the only sirenian in its range, which spans the waters of some 40 countries and territories throughout the Indo-West Pacific. The dugong is largely dependent on seagrass communities for subsistence and is thus restricted to the coastal habitats which support seagrass meadows, with the largest dugong concentrations typically occurring in wide, shallow, protected areas such as bays, mangrove channels, the waters of large inshore islands and inter-reefal waters. The northern waters of Australia between Shark Bay and Moreton Bay are believed to be the dugong's contemporary stronghold. Like all modern sirenians, the dugong ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trichechidae
Trichechidae is a family of sirenians that includes all living manatees and several extinct genera. Systematics TRICHECHIDAE *MiosireninaeM. Voss. 2014. On the invalidity of Halitherium schinzii Kaup, 1838 (Mammalia, Sirenia), with comments on systematic consequences. Zoosystematics and Evolution 90(1):87-93 **''Anomotherium'' ***''Anomotherium langewieschei'' **''Miosiren'' ***''Miosiren canhami'' ***''Miosiren kocki'' *Trichechinae **''Trichechus'' ***''Trichechus inunguis'' - Amazonian Manatee ***''Trichechus manatus'' - West Indian Manatee ***''Trichechus senegalensis'' - African Manatee ***''Trichechus hesperamazonicus'' **''Potamosiren'' ***''Potamosiren magdalensis'' **''Ribodon ''Ribodon'' is an extinct genus of manatee that lived around South America (Ituzaingó Formation, then described as Entrerriana Formation, Argentina, Solimões Formation, Brazil and Urumaco Formation, Urumaco, Venezuela) during the Tortonian (May ...'' ***''Ribodon limbatus'' References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
African Manatee
The African manatee (''Trichechus senegalensis''), also known as the West African manatee, is a species of manatee that inhabits much of the western region of Africa – from Senegal to Angola. It is the only manatee species to be found in the Old World. Not a great deal is known about ''T. senegalensis.'' Taxonomy The African manatee was officially declared a species under the ''Trichechus senegalensis'' taxon in 1795 by naturalist Johann Heinrich Friedrich Link. No subspecies of this taxon are known. Although African manatees live in both coastal areas and isolated inland areas, genetic evidence suggests no significant differences between the two populations. The African manatee falls under the genus ''Trichechus'' with only two other species, the Amazonian manatee and the West Indian manatee, which are also sirenians. Range and habitat African manatees inhabit the widest ranges of habitats of any sirenian species, ranging from offshore islands in the Atlantic, rivers in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amazonian Manatee
The Amazonian manatee (''Trichechus inunguis'') is a species of manatee that lives in the Amazon Basin in Brazil, Peru, Colombia and Ecuador. It has thin, wrinkled brownish or gray colored skin, with fine hairs scattered over its body and a white chest patch. It is the smallest of the three extant species of manatee.''Trials of a Primatologist.'' - smithsonianmag.com. Accessed March 16, 2008. Taxonomy The specific name, ''inunguis'' is Latin for "nailless." The genus name ''Trichechus'', comes from Latin meaning "hair", referencing the whiskers around the manatee's mouth.Physical characteristics The Amazonian manatee is the smallest member of the manatee family and can be distinguished b ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dugongidae
Dugongidae is a family in the order of Sirenia. The family has one surviving species, the dugong (''Dugong dugon''), one recently extinct species, Steller's sea cow (''Hydrodamalis gigas''), and a number of extinct genera known from fossil records. Dugongidae's body weight ranges from 217 to 307 kg for juveniles, 334 to 424 kg for subadults, and 435 to 568.5 kg for adults. Oral temperatures for individual dugongs is determined from 24° to 34.2 °C. Heart rate readings are from 40 to 96 bpm and vary between individual dugongs. Respiration rate during the out-of-water phase is from 1 to 33. Taxonomy * Family DUGONGIDAE ** Genus †''Anisosiren'' ** Genus †''Caribosiren'' ** Genus †'' Indosiren'' ** Genus †''Lentiarenium'' ** Genus †''Kaupitherium'' ** Genus †'' Paralitherium'' ** Genus †''Priscosiren'' ** Genus †'' Prohalicore'' ** Genus †''Sirenavus'' ** Subfamily †Halitheriinae *** Genus †''Halitherium'' (''nomen dubium'') ** Subfamily ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manatee
Manatees (family Trichechidae, genus ''Trichechus'') are large, fully aquatic, mostly herbivorous marine mammals sometimes known as sea cows. There are three accepted living species of Trichechidae, representing three of the four living species in the order Sirenia: the Amazonian manatee (''Trichechus inunguis''), the West Indian manatee (''Trichechus manatus''), and the West African manatee (''Trichechus senegalensis''). They measure up to long, weigh as much as , and have paddle-like tails. Manatees are herbivores and eat over 60 different freshwater and saltwater plants. Manatees inhabit the shallow, marshy coastal areas and rivers of the Caribbean Sea, the Gulf of Mexico, the Amazon basin, and West Africa. The main causes of death for manatees are human-related issues, such as habitat destruction and human objects. Their slow-moving, curious nature has led to violent collisions with propeller-driven boats and ships. Some manatees have been found with over 50 scars on them ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene
The Eocene ( ) Epoch is a geological epoch (geology), epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period (geology), Period in the modern Cenozoic Era (geology), Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', "dawn") and (''kainós'', "new") and refers to the "dawn" of modern ('new') fauna that appeared during the epoch. The Eocene spans the time from the end of the Paleocene Epoch to the beginning of the Oligocene Epoch. The start of the Eocene is marked by a brief period in which the concentration of the carbon isotope Carbon-13, 13C in the atmosphere was exceptionally low in comparison with the more common isotope Carbon-12, 12C. The end is set at a major extinction event called the ''Grande Coupure'' (the "Great Break" in continuity) or the Eocene–Oligocene extinction event, which may be related to the impact of one or more large bolides in Popigai impact structure, Siberia and in what is now ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paenungulata
Paenungulata (from Latin ''paene'' "almost" + ''ungulātus'' "having Hoof, hoofs") is a clade of "sub-Ungulate, ungulates", which groups three Extant taxon, extant mammal Order (biology), orders: Proboscidea (including elephants), Sirenia (sirenia, sea cows, including dugongs and manatees), and Hyracoidea (hyraxes). At least two more possible orders are known only as fossils, namely Embrithopoda and Desmostylia. Molecular evidence indicates that Paenungulata (or at least its extant members) is part of the cohort Afrotheria, an ancient assemblage of mainly African mammals of great diversity. The other members of this cohort are the orders Afrosoricida (tenrecs and golden moles), Macroscelidea (elephant shrews) and Tubulidentata (aardvarks). Of the five orders, hyraxes are the most basal, followed by embrithopods; the remaining orders (sirenians and elephants) are more closely related. These latter three are grouped as the Tethytheria, because it is believed that their common ancest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Elephant
Elephants are the largest existing land animals. Three living species are currently recognised: the African bush elephant, the African forest elephant, and the Asian elephant. They are the only surviving members of the family Elephantidae and the order Proboscidea. The order was formerly much more diverse during the Pleistocene, but most species became extinct during the Late Pleistocene epoch. Distinctive features of elephants include a long proboscis called a trunk, tusks, large ear flaps, pillar-like legs, and tough but sensitive skin. The trunk is used for breathing, bringing food and water to the mouth, and grasping objects. Tusks, which are derived from the incisor teeth, serve both as weapons and as tools for moving objects and digging. The large ear flaps assist in maintaining a constant body temperature as well as in communication. African elephants have larger ears and concave backs, whereas Asian elephants have smaller ears, and convex or level backs. Elephants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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