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Mylodontid
Mylodontidae is a family of extinct South American and North American ground sloths within the suborder Folivora of order Pilosa, living from around 23 million years ago (Mya) to 11,000 years ago. This family is most closely related to another family of extinct ground sloths, Scelidotheriidae, as well as to the extant arboreal two-toed sloths, family Choloepodidae; together these make up the superfamily Mylodontoidea. Phylogenetic analyses based on morphology uncovered the relationship between Mylodontidae and Scelidotheriidae; in fact, the latter was for a time considered a subfamily of mylodontids. However, molecular sequence comparisons were needed for the correct placement of Choloepodidae. These studies have been carried out using mitochondrial DNA sequences as well as with collagen amino acid sequences. The latter results indicate that Choloepodidae is closer to Mylodontidae than Scelidotheriidae is. The only other living sloth family, Bradypodidae (three-toed sloths), belo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudoprepotherium
''Pseudoprepotherium'' is an extinct genus of sloths of the family Mylodontidae. It was widespread across northern South America during the Early to Late Miocene epoch around 21 to 5.3 million years ago. Fossils of the animal have been found in Brazil, Venezuela, and Peru. ''Pseudoprepotherium'' lived in a tropical climate with a water-rich environment. Their known remains are limited to limb bones, except for a few skulls and teeth. Based on these remains, they were most likely medium to large-sized mylodontid. The genus was described in 1961 and currently contains three species, which were originally assigned to the genus ''Prepotherium''. Description ''Pseudoprepotherium'' is a medium to a large-sized member of the family Mylodontidae. The material documented so far consists mainly of limb bones but includes individual skulls and remains of jaws. Body weight of around 550kg is reconstructed for the smaller relatives using a thigh bone around 42cm long. Large molds with femur l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mylodontoidea
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] |
Folivora
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] |
Ground Sloth
Ground sloths are a diverse group of extinct sloths in the mammalian superorder Xenarthra. The term is used to refer to all extinct sloths because of the large size of the earliest forms discovered, compared to existing tree sloths. The Caribbean ground sloths, the most recent survivors, lived in the Antilles, possibly until 1550 BCE. However, radiocarbon dating suggests an age of between 2819 and 2660 BCE for the last occurrence of ''Megalocnus'' in Cuba. Ground sloths had been extinct on the mainland of North and South America for 10,000 years or more. They survived 5,000–6,000 years longer in the Caribbean than on the American mainland, which correlates with the later colonization of this area by humans. Much ground sloth evolution took place during the late Paleogene and Neogene of South America, while the continent was isolated. At their earliest appearance in the fossil record, the ground sloths were already distinct at the family level. The presence ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paramylodon Harlani
''Paramylodon'' is an extinct genus of ground sloth of the family Mylodontidae endemic to North America during the Pliocene through Pleistocene epochs, living from around ~4.9 Mya–11,000 years ago. It is also known as Harlan's ground sloth. Due to the partly very good fossil preservation, the body armor typical for the mylodonts has mostly been preserved in the form of osteoderms. In addition, a sex-specific difference in cranial structure can be demonstrated. According to the finds, the representatives of ''Paramylodon'' lived in open landscapes, sometimes also in mountainous locations, and most likely fed on grass-eating or mixed plant diets. Unique trace fossils also provide information about the locomotion of the animals, which was quadrupedal. In addition, due to the design of the forelimbs, a certain burrowing way of life cannot be disputed. Within the genus only two species are recognized: ''Paramylodon harlani'' and ''Paramylodon garbanii''. The first fossil findings d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pilosa
The order Pilosa is a clade of xenarthran placental mammals, native to the Americas. It includes the anteaters and sloths (which includes the extinct ground sloths). The name comes from the Latin word for "hairy". Origins and taxonomy The biogeographic origins of the Pilosa are still unclear, but they can be traced back in South America as far as the early Paleogene (about 60 million years ago, only a short time after the end of the Mesozoic Era). The presence of these animals in Central America and their former presence in North America is a result of the Great American Interchange. A number of sloths were also formerly present on the Antilles, which they reached from South America by some combination of rafting or floating with the prevailing currents. Together with the armadillos, which are in the order Cingulata, pilosans are part of the larger superorder Xenarthra, a defining characteristic of which is the presence of xenarthrals (extra formations between lumbar verte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eionaletherium
''Eionaletherium'' is an extinct genus of ground sloth from the Late Miocene coasts of Venezuela containing one species: ''E. tanycnemius''. Taxonomy ''Eionaletherium'' was discovered in the Late Miocene Urumaco Formation in the Falcón State of Venezuela and described in 2015 as a species of mylodontid ground sloth. It is a member of the family Mylodontidae in a clade including ''Bolivartherium'', and ''Glossotherium''. The holotype specimen, IVIC-P-2870, housed at the Venezuelan Institute for Scientific Research, comprises the femurs, a tibia, fibula, some vertebrae, and fragments of the scapulae, ribs, and the ankle bone. The genus name ''Eionaletherium'' comes from the Greek words ''eion'' (shore), ''ale'' (wanderer), and ''therium'' (beast), in reference to the nearshore environment it probably inhabited. The species name ''tanycnemius'' comes from Greek ''tany'' (long) and ''cnemius'' (shin). Description ''Eionaletherium'', based on a femur-to-body-size ratio, is estimat ... [...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] |
Proceedings Of The National Academy Of Sciences
''Proceedings of the National Academy of Sciences of the United States of America'' (often abbreviated ''PNAS'' or ''PNAS USA'') is a peer-reviewed multidisciplinary scientific journal. It is the official journal of the National Academy of Sciences, published since 1915, and publishes original research, scientific reviews, commentaries, and letters. According to ''Journal Citation Reports'', the journal has a 2021 impact factor of 12.779. ''PNAS'' is the second most cited scientific journal, with more than 1.9 million cumulative citations from 2008 to 2018. In the mass media, ''PNAS'' has been described variously as "prestigious", "sedate", "renowned" and "high impact". ''PNAS'' is a delayed open access journal, with an embargo period of six months that can be bypassed for an author fee ( hybrid open access). Since September 2017, open access articles are published under a Creative Commons license. Since January 2019, ''PNAS'' has been online-only, although print issues are a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitochondrial DNA
Mitochondrial DNA (mtDNA or mDNA) is the DNA located in mitochondria, cellular organelles within eukaryotic cells that convert chemical energy from food into a form that cells can use, such as adenosine triphosphate (ATP). Mitochondrial DNA is only a small portion of the DNA in a eukaryotic cell; most of the DNA can be found in the cell nucleus and, in plants and algae, also in plastids such as chloroplasts. Human mitochondrial DNA was the first significant part of the human genome to be sequenced. This sequencing revealed that the human mtDNA includes 16,569 base pairs and encodes 13 proteins. Since animal mtDNA evolves faster than nuclear genetic markers, it represents a mainstay of phylogenetics and evolutionary biology. It also permits an examination of the relatedness of populations, and so has become important in anthropology and biogeography. Origin Nuclear and mitochondrial DNA are thought to be of separate evolutionary origin, with the mtDNA being derived ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phylogenetic
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups of organisms. These relationships are determined by Computational phylogenetics, phylogenetic inference methods that focus on observed heritable traits, such as DNA sequences, protein amino acid sequences, or morphology. The result of such an analysis is a phylogenetic tree—a diagram containing a hypothesis of relationships that reflects the evolutionary history of a group of organisms. The tips of a phylogenetic tree can be living taxa or fossils, and represent the "end" or the present time in an evolutionary lineage. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the tree. An unrooted tree diagram (a network) makes no assumption about the ancestral line, and does ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
