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Arctostylopidae
Arctostylopidae is an extinct family of placental mammals from the Late Palaeocene of Eastern Asia and North America. All arctostylopid specimens in North America have been referred to the genus '' Arctostylops''. They are animals of uncertain affinities to other groups and it was believed that they may be related to 'ungulate Ungulates ( ) are members of the diverse clade Euungulata ("true ungulates"), which primarily consists of large mammals with Hoof, hooves. Once part of the clade "Ungulata" along with the clade Paenungulata, "Ungulata" has since been determined ...s'. Originally they were considered to be northern relatives of South American notoungulates, specifically Notostylopidae. Recently, other palaeontologists have suggested that they might be descendants of Asian gliriforms, and therefore related to rabbits and rodents. This relationship is based upon similarities in the shape of their tarsal (ankle) bones. In particular, arctostylopid tarsals bear a strong r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euarchontoglires
Euarchontoglires (from: '' Euarchonta'' ("true rulers") + '' Glires'' ("dormice")), synonymous with Supraprimates, is a clade and a superorder of placental mammals, the living members of which belong to one of the five following groups: rodents, lagomorphs, treeshrews, primates, and colugos. Evolutionary affinities within mammals The Euarchontoglires clade is based on DNA sequence analyses and retrotransposon markers that combine the clades Glires (Rodentia + Lagomorpha) and Euarchonta (Scandentia + Primates + Dermoptera). It is usually discussed without a taxonomic rank but has been called a cohort, magnorder, or superorder. Relations among the four cohorts (Euarchontoglires, Xenarthra, Laurasiatheria, Afrotheria) and the identity of the placental root remain controversial. So far, few, if any, distinctive anatomical features have been recognized that support Euarchontoglires; nor does any strong evidence from anatomy support alternative hypotheses. Although both Eu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gliriformes
Euarchontoglires (from: ''Euarchonta'' ("true rulers") + ''Glires'' ("dormice")), synonymous with Supraprimates, is a clade and a superorder of placental mammals, the living members of which belong to one of the five following groups: rodents, lagomorphs, treeshrews, primates, and colugos. Evolutionary affinities within mammals The Euarchontoglires clade is based on DNA sequence analyses and retrotransposon markers that combine the clades Glires (Rodentia + Lagomorpha) and Euarchonta (Scandentia + Primates + Dermoptera). It is usually discussed without a taxonomic rank but has been called a cohort, magnorder, or superorder. Relations among the four cohorts (Euarchontoglires, Xenarthra, Laurasiatheria, Afrotheria) and the identity of the placental root remain controversial. So far, few, if any, distinctive anatomical features have been recognized that support Euarchontoglires; nor does any strong evidence from anatomy support alternative hypotheses. Although both Euarchontoglire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Paleocene
The Thanetian is, in the International Commission on Stratigraphy, ICS Geologic timescale, the latest age (geology), age or uppermost stage (stratigraphy), stratigraphic stage of the Paleocene epoch (geology), Epoch or series (stratigraphy), Series. It spans the time between . The Thanetian is preceded by the Selandian Age and followed by the Ypresian Age (part of the Eocene). The Thanetian is sometimes referred to as the Late Paleocene. Stratigraphic definition The Thanetian was established by Switzerland, Swiss geologist Eugène Renevier in 1873. The Thanetian is named after the Thanet Formation, the oldest Cenozoic deposit of the London Basin, which was first identified in the area of Kent (southern England) known as the Isle of Thanet. The base of the Thanetian Stage is laid at the base of magnetic chronozone C26n. The references profile (Global Boundary Stratotype Section and Point) is in the Zumaia section (43° 18'N, 2° 16'W) at the beach of Itzurun, Pais Vasco, northern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eocene Mammals
The Eocene ( ) is a geological epoch that lasted from about 56 to 33.9 million years ago (Ma). It is the second epoch of the Paleogene Period in the modern Cenozoic 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.See: *Letter from William Whewell to Charles Lyell dated 31 January 1831 in: * From p. 55: "The period next antecedent we shall call Eocene, from ήως, aurora, and χαινος, recens, because the extremely small proportion of living species contained in these strata, indicates what may be considered the first commencement, or ''dawn'', of the existing state of the animate creation." 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 13C in the atmosphere was exceptionally low in co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleocene Mammals
The Paleocene ( ), or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''palaiós'' meaning "old" and the Eocene Epoch (which succeeds the Paleocene), translating to "the old part of the Eocene". The epoch is bracketed by two major events in Earth's history. The K–Pg extinction event, brought on by an asteroid impact ( Chicxulub impact) and possibly volcanism ( Deccan Traps), marked the beginning of the Paleocene and killed off 75% of species, most famously the non-avian dinosaurs. The end of the epoch was marked by the Paleocene–Eocene Thermal Maximum (PETM), which was a major climatic event wherein about 2,500–4,500 gigatons of carbon were released into the atmosphere and ocean systems, causing a spike in global temperatures and ocean acidification. In the Paleocene, the continents of the Northern He ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Mammal Families
Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared years ago. It took thousands of years for writing systems to be widely adopted, with writing having spread to almost all cultures by the 19th century. The end of prehistory therefore came at different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. It is based on an old conception of history that without written records there could be no history. The most common conception today is that history is based on evidence, however the concept of prehistory hasn't been completely discarded. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Notoungulata
Notoungulata is an extinct order of ungulates that inhabited South America from the early Paleocene to the end of the Pleistocene, living from approximately 61 million to 11,000 years ago. Notoungulates were morphologically diverse, with forms resembling animals as disparate as rabbits and rhinoceroses. Notoungulata are the largest group of South American native ungulates, with over 150 genera in 14 families having been described, divided into two major subgroupings, Typotheria and Toxodontia. Notoungulates first diversified during the Eocene. Their diversity declined from the late Neogene onwards, with only the large Toxodontidae, toxodontids persisting until the end of the Pleistocene (with ''Mixotoxodon'' expanding into Central America and southern North America), perishing as part of the Late Pleistocene extinctions, Late Pleistocene megafauna extinctions along with most other large mammals across the Americas. Collagen sequence analysis suggests that notoungulates are closely ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ungulate
Ungulates ( ) are members of the diverse clade Euungulata ("true ungulates"), which primarily consists of large mammals with Hoof, hooves. Once part of the clade "Ungulata" along with the clade Paenungulata, "Ungulata" has since been determined to be a polyphyletic and thereby invalid clade based on molecular data. As a result, true ungulates had since been reclassified to the newer clade Euungulata in 2001 within the clade Laurasiatheria while Paenungulata has been reclassified to a distant clade Afrotheria. Living ungulates are divided into two orders: Perissodactyla including Equidae, equines, rhinoceroses, and tapirs; and Artiodactyla including Bos, cattle, antelope, Sus (genus), pigs, giraffes, camels, Ovis, sheep, deer, and Hippopotamidae, hippopotamuses, among others. Cetaceans such as Whale, whales, Dolphin, dolphins, and Porpoise, porpoises are also classified as artiodactyls, although they do not have hooves. Most terrestrial ungulates use the hoofed tips of their toes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palaeocene
The Paleocene ( ), or Palaeocene, is a geological epoch that lasted from about 66 to 56 million years ago (mya). It is the first epoch of the Paleogene Period in the modern Cenozoic Era. The name is a combination of the Ancient Greek ''palaiós'' meaning "old" and the Eocene Epoch (which succeeds the Paleocene), translating to "the old part of the Eocene". The epoch is bracketed by two major events in Earth's history. The K–Pg extinction event, brought on by an asteroid impact (Chicxulub impact) and possibly volcanism ( Deccan Traps), marked the beginning of the Paleocene and killed off 75% of species, most famously the non-avian dinosaurs. The end of the epoch was marked by the Paleocene–Eocene Thermal Maximum (PETM), which was a major climatic event wherein about 2,500–4,500 gigatons of carbon were released into the atmosphere and ocean systems, causing a spike in global temperatures and ocean acidification. In the Paleocene, the continents of the Northern Hemispher ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placental Mammal
Placental mammals ( infraclass Placentalia ) are one of the three extant subdivisions of the class Mammalia, the other two being Monotremata and Marsupialia. Placentalia contains the vast majority of extant mammals, which are partly distinguished from monotremes and marsupials in that the fetus is carried in the uterus of its mother to a relatively late stage of development. The name is something of a misnomer, considering that marsupials also nourish their fetuses via a placenta, though for a relatively briefer period, giving birth to less-developed young, which are then nurtured for a period inside the mother's pouch. Placentalia represents the only living group within Eutheria, which contains all mammals that are more closely related to placentals than they are to marsupials. Anatomical features Placental mammals are anatomically distinguished from other mammals by: * a sufficiently wide opening at the bottom of the pelvis to allow the birth of a large baby relative to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
