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Three-toed Sloth
The three-toed or three-fingered sloths are arboreal neotropical mammals . They are the only members of the genus ''Bradypus'' and the family Bradypodidae. The four living species of three-toed sloths are the brown-throated sloth, the maned sloth, the pale-throated sloth, and the pygmy three-toed sloth. In complete contrast to past morphological studies, which tended to place ''Bradypus'' as the sister group to all other folivorans, molecular studies place them nested within the sloth superfamily Megatherioidea, making them the only surviving members of that radiation. Extant species Evolution A study of mitochondrial cytochrome b and 16S rRNA sequences suggests that '' B. torquatus'' diverged from '' B. variegatus'' and '' B. tridactylus'' about 12 million years ago, while the latter two split 5 to 6 million years ago. The diversification of ''B. variegatus'' lineages was estimated to have started 4 to 5 million years ago. Relation to the two-toed sloth Both types of sloth t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brown-throated Three-toed Sloth
The brown-throated sloth (''Bradypus variegatus'') is a species of three-toed sloth found in the Neotropical realm of Central and South America. It is the most common of the four species of three-toed sloth, and is found in the forests of South and Central America. Description The brown-throated sloth is of similar size and build to most other species of three-toed sloths, with both males and females being in total body length. The tail is relatively short, only long. Adults weigh from , with no significant size difference between males and females. Each foot has three fingers, ending in long, curved claws, which are long on the fore feet, and on the hind feet. The head is rounded, with a blunt nose and inconspicuous ears. As with other sloths, the brown-throated sloth has no incisor or canine teeth, and the cheek teeth are simple and peg-like. They have no gall bladder, cecum, or appendix. The brown-throated sloth has grayish-brown to beige-color fur over the body, wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Megatherioidea
Sloths are a group of Neotropical xenarthran mammals constituting the suborder Folivora, including the extant arboreal tree sloths and extinct terrestrial ground sloths. Noted for their slowness of movement, tree sloths spend most of their lives hanging upside down in the trees of the tropical rainforests of South America and Central America. Sloths are considered to be most closely related to anteaters, together making up the xenarthran order Pilosa. There are six extant sloth species in two genera – '' Bradypus'' (three–toed sloths) and '' Choloepus'' (two–toed sloths). Despite this traditional naming, all sloths have three toes on each rear limb-- although two-toed sloths have only two digits on each forelimb. The two groups of sloths are from different, distantly related families, and are thought to have evolved their morphology via parallel evolution from terrestrial ancestors. Besides the extant species, many species of ground sloths ranging up to the size of elep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two-toed Sloth
''Choloepus'' is a genus of xenarthran mammals of Central and South America within the monotypic family Choloepodidae, consisting of two-toed sloths, sometimes also called two-fingered sloths. The two species of ''Choloepus'' (which means "lame foot"), Linnaeus's two-toed sloth (''Choloepus didactylus'') and Hoffmann's two-toed sloth (''Choloepus hoffmanni''), were formerly believed on the basis of morphological studies to be the only surviving members of the sloth family Megalonychidae, but have now been shown by molecular results to be closest to extinct ground sloths of the family Mylodontidae. Extant species Evolution A study of retrovirus and mitochondrial DNA suggests that ''C. didactylus'' and ''C. hoffmani'' diverged 6 to 7 million years ago. Furthermore, based on cytochrome c oxidase subunit I sequences, a similar divergence date ( years ago) between the two populations of ''C. hofmanni'' separated by the Andes has been reported. Their ancestors evolved with mari ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sloth
Sloths are a group of Neotropical xenarthran mammals constituting the suborder Folivora, including the extant arboreal tree sloths and extinct terrestrial ground sloths. Noted for their slowness of movement, tree sloths spend most of their lives hanging upside down in the trees of the tropical rainforests of South America and Central America. Sloths are considered to be most closely related to anteaters, together making up the xenarthran order Pilosa. There are six extant sloth species in two genera – '' Bradypus'' (three–toed sloths) and '' Choloepus'' (two–toed sloths). Despite this traditional naming, all sloths have three toes on each rear limb-- although two-toed sloths have only two digits on each forelimb. The two groups of sloths are from different, distantly related families, and are thought to have evolved their morphology via parallel evolution from terrestrial ancestors. Besides the extant species, many species of ground sloths ranging up to the size of ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pale-throated Sloth
The pale-throated sloth (''Bradypus tridactylus''), occasionally known as the ai (), is a species of three-toed sloth that inhabits tropical rainforests in northern South America. It is similar in appearance to, and often confused with, the brown-throated sloth, which has a much wider distribution. Genetic evidence has been interpreted to suggest the two species diverged only around 400,000 years ago, although the most recent evidence indicates the split was closer to 6 million years. Description Pale-throated sloths have a rounded head with a blunt nose and small external ears. The limbs are long and weak, with the arms being nearly twice the length of the hindlimbs. The hands and feet each have three digits, armed with long, arched claws, with the middle claw being the largest and most powerful. Males are in head-body length, with a short, , tail, and weigh from . However, the females are noticeably larger, being from in length, and weighing . The body is covered with coars ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brown-throated Sloth
The brown-throated sloth (''Bradypus variegatus'') is a species of three-toed sloth found in the Neotropical realm of Central and South America. It is the most common of the four species of three-toed sloth, and is found in the forests of South and Central America. Description The brown-throated sloth is of similar size and build to most other species of three-toed sloths, with both males and females being in total body length. The tail is relatively short, only long. Adults weigh from , with no significant size difference between males and females. Each foot has three fingers, ending in long, curved claws, which are long on the fore feet, and on the hind feet. The head is rounded, with a blunt nose and inconspicuous ears. As with other sloths, the brown-throated sloth has no incisor or canine teeth, and the cheek teeth are simple and peg-like. They have no gall bladder, cecum, or appendix. The brown-throated sloth has grayish-brown to beige-color fur over the body, wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maned Sloth
The maned sloth (''Bradypus torquatus'') is a three-toed sloth that is native to South America. It is one of four species of three-toed sloths belonging to the suborder Xenarthra and are placental mammals. They are endemic to the Atlantic coastal rainforest of southeastern and northeastern Brazil, located in the states of Espírito Santo, Rio de Janeiro and Bahia. Each of the individuals within the species are genetically distinct with different genetic makeup.The maned sloth is listen under Vulnerable (VU) according to the IUCN Red List and have a decreasing population trend. Distribution and habitat The maned sloth is found only in the Atlantic coastal rainforest of southeastern and northeastern Brazil. The sloths are an endemic species unique to Espírito Santo, Rio de Janeiro and Bahia. The largest number of individuals that inhabit the same space within the species currently occupy the state of Bahia. Bahia is also the location for the largest number of genetically divers ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MT-RNR2
Mitochondrially encoded 16S RNA (often abbreviated as ''16S'') is the mitochondrial large subunit ribosomal RNA that in humans is encoded by the MT-RNR2 gene. The MT-RNR2 gene also encodes the Humanin polypeptide that has been the target of Alzheimer's disease research. The 16S rRNA is the mitochondrial homologue of the prokaryotic 23S and eukaryotic nuclear 28S ribosomal RNAs. See also * Mitochondrial DNA * Humanin Humanin is a micropeptide encoded in the mitochondrial genome by the 16S ribosomal RNA gene, MT-RNR2. Its structure contains a three-turn α-helix, and no symmetry. In ''in vitro'' and animal models, it appears to have cytoprotective effects. ... References Ribosomal RNA Human mitochondrial genes {{genetics-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytochrome B
Cytochrome b within both molecular and cell biology, is a protein found in the mitochondria of eukaryotic cells. It functions as part of the electron transport chain and is the main subunit of transmembrane cytochrome bc1 and b6f complexes. Function In the mitochondrion of eukaryotes and in aerobic prokaryotes, cytochrome b is a component of respiratory chain complex III () — also known as the bc1 complex or ubiquinol-cytochrome c reductase. In plant chloroplasts and cyanobacteria, there is an analogous protein, cytochrome b6, a component of the plastoquinone-plastocyanin reductase (), also known as the b6f complex. These complexes are involved in electron transport, the pumping of protons to create a proton-motive force ( PMF). This proton gradient is used for the generation of ATP. These complexes play a vital role in cells. Structure Cytochrome b/b6 is an integral membrane protein of approximately 400 amino acid residues that probably has 8 transmembrane segments. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pale-throated Three-toed Sloth
The pale-throated sloth (''Bradypus tridactylus''), occasionally known as the ai (), is a species of three-toed sloth that inhabits tropical rainforests in northern South America. It is similar in appearance to, and often confused with, the brown-throated sloth, which has a much wider distribution. Genetic evidence has been interpreted to suggest the two species diverged only around 400,000 years ago, although the most recent evidence indicates the split was closer to 6 million years. Description Pale-throated sloths have a rounded head with a blunt nose and small external ears. The limbs are long and weak, with the arms being nearly twice the length of the hindlimbs. The hands and feet each have three digits, armed with long, arched claws, with the middle claw being the largest and most powerful. Males are in head-body length, with a short, , tail, and weigh from . However, the females are noticeably larger, being from in length, and weighing . The body is covered with coars ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
