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Ralli (suborder)
The Gruiformes are an order containing a considerable number of living and extinct bird families, with a widespread geographical diversity. Gruiform means "crane-like". Traditionally, a number of wading and terrestrial bird families that did not seem to belong to any other order were classified together as Gruiformes. These include 14 species of large cranes, about 145 species of smaller crakes and rails, as well as a variety of families comprising one to three species, such as the Heliornithidae, the limpkin, or the Psophiidae. Other birds have been placed in this order more out of necessity to place them ''somewhere''; this has caused the expanded Gruiformes to lack distinctive apomorphies. Recent studies indicate that these "odd Gruiformes" are if at all only loosely related to the cranes, rails, and relatives ("core Gruiformes"). Systematics There are only two suprafamilial clades (natural groups) among the birds traditionally classified as Gruiformes. Rails (Rallidae), f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paleocene
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 and possibly volcanism, marked the beginning of the Paleocene and killed off 75% of living 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 Hemisphere were still connected v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gondwanaland
Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages of break-up, involving the separation of Antarctica from South America (forming the Drake Passage) and Australia, occurred during the Paleogene. Gondwana was not considered a supercontinent by the earliest definition, since the landmasses of Baltica, Laurentia, and Siberia were separated from it. To differentiate it from the Indian region of the same name (see ), it is also commonly called Gondwanaland. Gondwana was formed by the accretion of several cratons. Eventually, Gondwana became the largest piece of continental crust of the Palaeozoic Era, covering an area of about , about one-fifth of the Earth's surface. During the Carboniferous Period, it merged with Laurasia to form a larger supercontinent called Pangaea. Gondwana (and Panga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gondwana
Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages of break-up, involving the separation of Antarctica from South America (forming the Drake Passage) and Australia, occurred during the Paleogene. Gondwana was not considered a supercontinent by the earliest definition, since the landmasses of Baltica, Laurentia, and Siberia were separated from it. To differentiate it from the Indian region of the same name (see ), it is also commonly called Gondwanaland. Gondwana was formed by the accretion of several cratons. Eventually, Gondwana became the largest piece of continental crust of the Palaeozoic Era, covering an area of about , about one-fifth of the Earth's surface. During the Carboniferous Period, it merged with Laurasia to form a larger supercontinent called Pangaea. Gondwana ... [...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 deri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA–DNA Hybridization
In genomics, DNA–DNA hybridization is a molecular biology technique that measures the degree of genetic similarity between pools of DNA sequences. It is usually used to determine the genetic distance between two organisms and has been used extensively in phylogeny and taxonomy. Method The DNA of one organism is labelled, then mixed with the unlabelled DNA to be compared against. The mixture is incubated to allow DNA strands to dissociate and then cooled to form renewed hybrid double-stranded DNA. Hybridized sequences with a high degree of similarity will bind more firmly, and require more energy to separate them: i.e. they separate when heated at a higher temperature than dissimilar sequences, a process known as "DNA melting". To assess the melting profile of the hybridized DNA, the double-stranded DNA is bound to a column and the mixture is heated in small steps. At each step, the column is washed; sequences that melt become single-stranded and wash off the column. The tem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Otididae
Bustards, including floricans and korhaans, are large, terrestrial birds living mainly in dry grassland areas and on the steppes of the Old World. They range in length from . They make up the family Otididae (, formerly known as Otidae). Bustards are omnivorous and opportunistic, eating leaves, buds, seeds, fruit, small vertebrates, and invertebrates.del Hoyo, J. Elliott, A. & Sargatal, J. (editors). (1996) ''Handbook of the Birds of the World. Volume 3: Hoatzin to Auks''. Lynx Edicions. There are 26 species currently recognised. Description Bustards are all fairly large with the two largest species, the kori bustard (''Ardeotis kori'') and the great bustard (''Otis tarda''), being frequently cited as the world's heaviest flying birds. In both the largest species, large males exceed a weight of , weigh around on average and can attain a total length of . The smallest species is the little brown bustard (''Eupodotis humilis''), which is around long and weighs around on avera ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pedionomidae
The plains-wanderer (''Pedionomus torquatus'') is a bird, the only representative of family Pedionomidae and genus ''Pedionomus''. It is endemic to Australia. The majority of the remaining population is found in the Riverina region of New South Wales. Description The plains-wanderer is a quail-like ground bird, measuring 15–19 cm. It is such an atypical bird that it is placed in an entire family of its own, Pedionomidae. The adult male is light brown above, with fawn-white underparts with black crescents. The adult female is substantially larger than the male, and has a distinctive white-spotted black collar. They have excellent camouflage, and will first hide at any disturbance. If approached too closely, they will run rather than fly, at which they are very poor. Females lay four eggs, which the male then incubates. Taxonomy It was formerly believed to be related to the buttonquails and thus placed in the gamebird order Galliformes or with the cranes and rails ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turnicidae
Buttonquail or hemipodes are members of a small family of birds, Turnicidae, which resemble, but are unrelated to, the quails of Phasianidae. They inhabit warm grasslands in Asia, Africa, Europe, and Australia. There are 18 species in two genera, with most species placed in the genus ''Turnix'' and a single species in the genus '' Ortyxelos''. Buttonquails are small, drab, running birds, which avoid flying. The female is the more richly colored of the sexes. While the quail-plover is thought to be monogamous, ''Turnix'' buttonquails are sequentially polyandrous; both sexes cooperate in building a nest in the earth, but normally only the male incubates the eggs and tends the young, while the female may go on to mate with other males. Taxonomy The genus ''Turnix'' was introduced in 1791 by French naturalist in Pierre Bonnaterre. The genus name is an abbreviation of the genus ''Coturnix''. The type species was subsequently designated as the common buttonquail. The buttonquail ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesitornithidae
The mesites (Mesitornithidae) are a family of birds that are part of a clade ( Columbimorphae) that include Columbiformes and Pterocliformes. They are smallish flightless or near flightless birds endemic to Madagascar. They are the only family with more than two species in which every species is threatened (all three are listed as vulnerable). Description The mesites are forest and scrubland birds that feed on insects and seeds. The brown and white-breasted mesites forage on the ground, gleaning insects from the leaves and under them, as well as low vegetation. The subdesert mesite uses its long bill to probe in the soil. Other birds, such as drongos and flycatchers, will follow mesites to catch any insects they flush and miss. Mesites are vocal birds, with calls similar to passerine song, used for territorial defence. Two or three white eggs are laid in a stick-nest located in a bush or low branch. The ''Mesitornis'' species are monogamous while ''Monias benschi'' is polygamo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sunbittern
The sunbittern (''Eurypyga helias'') is a bittern-like bird of tropical regions of the Americas, and the sole member of the family Eurypygidae (sometimes spelled Eurypigidae) and genus ''Eurypyga''. It is found in Central and South America, and has three subspecies. The sunbittern shows both morphological and molecular similarities with the kagu (''Rhynochetos jubatus'') of New Caledonia, indicating a gondwanic origin, both species being placed in the clade Eurypygiformes.del Hoyo, J. Elliott, A. & Sargatal, J. (editors). (1996) ''Handbook of the Birds of the World. Volume 3: Hoatzin to Auks''. Lynx Edicions. Taxonomy The sunbittern is usually placed in the Gruiformes, but this was always considered preliminary. Altogether, the bird is most similar to another bird that was provisionally placed in the Gruiformes, the kagu (''Rhynochetos jubatus''). Molecular studies seem to confirm that the kagu and sunbittern are each other's closest living relatives and have a similar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.JPG "Click for more on -> Otididae")
