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Flightless Birds
Flightless birds are birds that through evolution lost the ability to fly. There are over 60 extant species, including the well known ratites ( ostriches, emu, cassowaries, rheas, and kiwi) and penguins. The smallest flightless bird is the Inaccessible Island rail (length 12.5 cm, weight 34.7 g). The largest (both heaviest and tallest) flightless bird, which is also the largest living bird, is the ostrich (2.7 m, 156 kg). Many domesticated birds, such as the domestic chicken and domestic duck, have lost the ability to fly for extended periods, although their ancestral species, the red junglefowl and mallard, respectively, are capable of extended flight. A few particularly bred birds, such as the Broad Breasted White turkey, have become totally flightless as a result of selective breeding; the birds were bred to grow massive breast meat that weighs too much for the bird's wings to support in flight. Flightlessness has evolved in many different birds independ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Penguins Edinburgh Zoo 2004 SMC
Penguins (order (biology), order List of Sphenisciformes by population, Sphenisciformes , family (biology), family Spheniscidae ) are a group of Water bird, aquatic flightless birds. They live almost exclusively in the Southern Hemisphere: only one species, the Galápagos penguin, is found north of the Equator. Highly adapted for life in the water, penguins have Countershading, countershaded dark and white plumage and flippers for swimming. Most penguins feed on krill, fish, squid and other forms of sea life which they catch with their bills and swallow it whole while swimming. A penguin has a spiny tongue and powerful jaws to grip slippery prey. They spend roughly half of their lives on land and the other half in the sea. The largest living species is the emperor penguin (''Aptenodytes forsteri''): on average, adults are about tall and weigh . The smallest penguin species is the Little penguin, little blue penguin (''Eudyptula minor''), also known as the fairy penguin, whic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mallard
The mallard () or wild duck (''Anas platyrhynchos'') is a dabbling duck that breeds throughout the temperate and subtropical Americas, Eurasia, and North Africa, and has been introduced to New Zealand, Australia, Peru, Brazil, Uruguay, Argentina, Chile, Colombia, the Falkland Islands, and South Africa. This duck belongs to the subfamily Anatinae of the waterfowl family Anatidae. Males have purple patches on their wings, while the females (hens or ducks) have mainly brown-speckled plumage. Both sexes have an area of white-bordered black or iridescent blue feathers called a speculum on their wings; males especially tend to have blue speculum feathers. The mallard is long, of which the body makes up around two-thirds the length. The wingspan is and the bill is long. It is often slightly heavier than most other dabbling ducks, weighing . Mallards live in wetlands, eat water plants and small animals, and are social animals preferring to congregate in groups or flocks of varyin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Island Gigantism
Island gigantism, or insular gigantism, is a biological phenomenon in which the size of an animal species isolated on an island increases dramatically in comparison to its mainland relatives. Island gigantism is one aspect of the more general Foster's rule, "island effect" or "Foster's rule", which posits that when mainland animals colonize islands, small species tend to evolve larger bodies, and large species tend to evolve smaller bodies (insular dwarfism). This is itself one aspect of the more general phenomenon of island syndrome which describes the differences in Morphology (biology), morphology, ecology, physiology and ethology, behaviour of insular species compared to their continental counterparts. Following the arrival of humans and associated introduced predators (dogs, cats, rats, pigs), many giant as well as other island endemics have become Extinction, extinct. A similar size increase, as well as increased woodiness, has been observed in some insular plants. Possible ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cursorial
A cursorial organism is one that is adapted specifically to run. An animal can be considered cursorial if it has the ability to run fast (e.g. cheetah) or if it can keep a constant speed for a long distance (high endurance). "Cursorial" is often used to categorize a certain locomotor mode, which is helpful for biologists who examine behaviors of different animals and the way they move in their environment. Cursorial adaptations can be identified by morphological characteristics (e.g. loss of lateral digits as in ungulate species), physiological characteristics, maximum speed, and how often running is used in life. There is much debate over how to define a cursorial animal specifically. The most accepted definitions include that a cursorial organism could be considered adapted to long-distance running at high speeds or has the ability to accelerate quickly over short distances. Among vertebrates, animals under 1 kg of mass are rarely considered cursorial, and cursorial behaviors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Origin Of Birds
The scientific question of within which larger group of animals birds evolved has traditionally been called the "origin of birds". The present scientific consensus is that birds are a group of maniraptoran theropod dinosaurs that originated during the Mesozoic Era. A close relationship between birds and dinosaurs was first proposed in the nineteenth century after the discovery of the primitive bird ''Archaeopteryx'' in Germany. Birds and extinct non-avian dinosaurs share many unique skeletal traits. Moreover, fossils of more than thirty species of non-avian dinosaur with preserved feathers have been collected. There are even very small dinosaurs, such as ''Microraptor'' and '' Anchiornis'', which have long, vaned arm and leg feathers forming wings. The Jurassic basal avialan '' Pedopenna'' also shows these long foot feathers. Paleontologist Lawrence Witmer concluded in 2009 that this evidence is sufficient to demonstrate that avian evolution went through a four-winged stage ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cretaceous–Paleogene Extinction Event
The Cretaceous–Paleogene (K–Pg) extinction event (also known as the Cretaceous–Tertiary extinction) was a sudden mass extinction of three-quarters of the plant and animal species on Earth, approximately 66 million years ago. With the exception of some ectothermic species such as sea turtles and crocodilians, no tetrapods weighing more than survived. It marked the end of the Cretaceous Period, and with it the Mesozoic era, while heralding the beginning of the Cenozoic era, which continues to this day. In the geologic record, the K–Pg event is marked by a thin layer of sediment called the K–Pg boundary, which can be found throughout the world in marine and terrestrial rocks. The boundary clay shows unusually high levels of the metal iridium, which is more common in asteroids than in the Earth's crust. As originally proposed in 1980 by a team of scientists led by Luis Alvarez and his son Walter, it is now generally thought that the K–Pg extinction was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dromornithidae
Dromornithidae, known as mihirungs and informally as thunder birds or demon ducks, were a clade of large, flightless Australian birds of the Oligocene through Pleistocene Epochs. All are now extinct. They were long classified in Struthioniformes, but are now usually classified as galloanseres. Dromornithids were part of the Australian megafauna. One species, ''Dromornis stirtoni'', was tall. Only a single species, ''Genyornis newtoni'' survived into the Late Pleistocene. They are thought to have been herbivorous. The scientific name Dromornithidae derives from the Greek words , ("swift-running") and , ("bird"). Classification The family was named by Max Fürbringer in 1888, citing W. B. Clarke and Gerard Krefft, Owen's separation from ''" Dromaeus"'' and ''Dinornis'', and a note by von Haast allying ''Dromornis'' with ''Dromaeus''. What the nearest relatives of this group are is a controversial issue. For many years it was thought that dromornithids were related to ratite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gastornithiformes
Gastornithiformes were an extinct order of giant flightless fowl with fossils found in North America, Eurasia, and possibly Australia. Members of Gastornithidae were long considered to be a part of the order Gruiformes. However, the traditional concept of Gruiformes has since been shown to be an unnatural grouping. Beginning in the late 1980s and the first phylogenetic analysis of gastornithid relationships, consensus began to grow that they were close relatives of the lineage that includes waterfowl and screamers, the Anseriformes. Recognizing the apparent close relationship between gastornis and waterfowl, some researchers even classify them within the anseriform group itself. Others restrict the name Anseriformes only to the crown group formed by all modern species, and label the larger group including extinct relatives of anseriformes in the clade Anserimorphae (which this article and related pages have adopted). While the order is generally considered to be monotypic, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geranoididae
Geranoididae is a clade of extinct birds from the early to late Eocene and possibly early Oligocene of North America and Europe. These were mid-sized, long-legged flightless birds.Gerald Mayr (2009). Paleogene Fossil Birds Recent research shows that these birds may actually be palaeognaths related to ostriches. Classification It is rather unambiguous that geranoidids are either part of or stem representatives of Gruoidea, the clade that includes modern cranes, limpkins and trumpeters, though their precise relationship varies among studies, some recovering them as sister taxa to another clade of flightless ratite-like birds, the eogruiids. The most recent consensus appears to be that geranoidids are outside of Gruoidea, with eogruiids being more closely related to modern cranes. However, Mayr (2019) argued that close affinities between Geranoididae and the palaeognathous family Palaeotididae are at least as well supported as the classification of geranoidids into the Gruiformes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eogruidae
Eogruidae (also spelled Eogruiidae in some publications) is a family of large, flightless birds that inhabited Asia from the Eocene to Pliocene epochs. Related to modern ostriches, it was formerly thought to be related to cranes, limpkins and trumpeters and that the similarities with ostriches were due to similar speciations to cursoriality, with both groups showing reduced numbers of toes to two in some taxa.Kurochkin, E.N. 1976. A survey of the Paleogene birds of Asia. Smithsonian Contributions to Paleobiology 27:75-86.Kurochkin, E.N. 1981. New representatives and evolution of two archaic gruiform families in Eurasia. Transactions of the Soviet-Mongolian Paleontologial Expedition 15:59-85. It has been suggested that competition from true ostriches has caused the extinction of these birds, though this has never been formally tested and several ostrich taxa do occur in the late Cenozoic of AsiaMayr, G. (2009). Paleogene fossil birds. Springer. and some species do occur in areas w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathornithids
Bathornithidae is an extinct family of birds from the Eocene to Miocene of North America. Part of Cariamiformes, they are related to the still extant seriemas and the also extinct Phorusrhacidae. They were likely similar in habits, being terrestrial, long-legged predators, some of which attained massive sizes. It has been suggested that most, if not all, North American Paleogene cariamiforme fossils are part of this group. Storrs Olson also referred the European '' Elaphrocnemus'' to this clade, though it has since been rejected. Conversely, some analysis have instead recovered them as a polyphyletic group, with ''Bathornis'' and kin being sister taxa to phorusrhacids while ''Paracrax'' is rendered closer to modern seriemas, though this assessment is heavily debated.Mayr, G., & Noriega, J. I. A well-preserved partial skeleton of the poorly known early Miocene seriema ''Noriegavis santacrucensis'' (Aves, Cariamidae). ''Acta palaeontologica Polonica'', 60(3):589-598. The most rece ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Terror Birds
Phorusrhacids, colloquially known as terror birds, are an extinct clade of large carnivorous flightless birds that were one of the largest species of apex predators in South America during the Cenozoic era; their conventionally accepted temporal range covers from 62 to 0.1 million years ( Ma) ago. They ranged in height from . Their closest modern-day relatives are believed to be the seriemas. '' Titanis walleri'', one of the larger species, is known from Texas and Florida in North America. This makes the phorusrhacids the only known large South American predator to migrate north in the Great American Interchange that followed the formation of the Isthmus of Panama land bridge (the main pulse of the interchange began about 2.6 Ma ago; ''Titanis'' at 5 Ma was an early northward migrant). It was once believed that ''T. walleri'' became extinct in North America around the time of the arrival of humans, but subsequent datings of ''Titanis'' fossils provided no evidence for their su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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