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Dinosaur
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic Geological period, period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the #Evolutionary history, evolution of dinosaurs is a subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya and their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record shows that birds are feathered dinosaurs, Evolution of birds, having evolved from earlier Theropoda, theropods during the Late Jurassic epoch, and are the only dinosaur lineage known to have survived the Cretaceous–Paleogene extinction event approximately 66 mya. Dinosaurs can therefore be divided into avian dinosaurs—birds—and the extinct non-avian dinosaurs, which are all dinosaurs other than birds. Dinosaurs are varied from taxonomy (biology), taxonomic, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sauropoda
Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their body), and four thick, pillar-like legs. They are notable for the enormous sizes attained by some species, and the group includes the largest animals to have ever lived on land. Well-known genera include ''Brachiosaurus'', ''Diplodocus'', ''Apatosaurus'' and ''Brontosaurus''. The oldest known unequivocal sauropod dinosaurs are known from the Early Jurassic. ''Isanosaurus'' and ''Antetonitrus'' were originally described as Triassic sauropods, but their age, and in the case of ''Antetonitrus'' also its sauropod status, were subsequently questioned. Sauropod-like sauropodomorph tracks from the Fleming Fjord Formation (Greenland) might, however, indicate the occurrence of the group in the Late Triassic. By the Late Jurassic (150 million yea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stegosaurus
''Stegosaurus'' (; ) is a genus of herbivorous, four-legged, armored dinosaur from the Late Jurassic, characterized by the distinctive kite-shaped upright plates along their backs and spikes on their tails. Fossils of the genus have been found in the western United States and in Portugal, where they are found in Kimmeridgian- to early Tithonian-aged strata, dating to between 155 and 145 million years ago. Of the species that have been classified in the upper Morrison Formation of the western US, only three are universally recognized: ''S. stenops'', ''S. ungulatus'' and ''S. sulcatus''. The remains of over 80 individual animals of this genus have been found. ''Stegosaurus'' would have lived alongside dinosaurs such as ''Apatosaurus'', ''Diplodocus'', ''Brachiosaurus'', ''Ceratosaurus'', and ''Allosaurus''; the latter two may have preyed on it. They were large, heavily built, herbivorous quadrupeds with rounded backs, short fore limbs, long hind limbs, and tails held hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dromaeosauridae
Dromaeosauridae () is a family of feathered theropod dinosaurs. They were generally small to medium-sized feathered carnivores that flourished in the Cretaceous Period. The name Dromaeosauridae means 'running lizards', from Greek ('), meaning 'runner', and ('), meaning 'lizard'. In informal usage, they are often called raptors (after ''Velociraptor''), a term popularized by the film '' Jurassic Park''; a few types include the term "raptor" directly in their name and have come to emphasize their bird-like appearance and speculated bird-like behavior. Dromaeosaurid fossils have been found across the globe in North America, Europe, Africa, Asia, South America and Antarctica, with some fossils giving credence to the possibility that they inhabited Australia as well. They first appeared in the mid-Jurassic Period (late Bathonian stage, about 167 million years ago) and survived until the end of the Cretaceous (Maastrichtian stage, 66 ma), existing until the Cretaceous–Paleogene ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hadrosaurid
Hadrosaurids (), or duck-billed dinosaurs, are members of the ornithischian family Hadrosauridae. This group is known as the duck-billed dinosaurs for the flat duck-bill appearance of the bones in their snouts. The ornithopod family, which includes genera such as ''Edmontosaurus'' and '' Parasaurolophus'', was a common group of herbivores during the Late Cretaceous Period. Hadrosaurids are descendants of the Upper Jurassic/Lower Cretaceous iguanodontian dinosaurs and had a similar body layout. Hadrosaurs were among the most dominant herbivores during the Late Cretaceous in Asia and North America, and during the close of the Cretaceous several lineages dispersed into Europe, Africa, South America and Antarctica. Like other ornithischians, hadrosaurids had a predentary bone and a pubic bone which was positioned backwards in the pelvis. Unlike more primitive iguanodonts, the teeth of hadrosaurids are stacked into complex structures known as dental batteries, which acted as effectiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Late Triassic
The Late Triassic is the third and final epoch (geology), epoch of the Triassic geologic time scale, Period in the geologic time scale, spanning the time between annum, Ma and Ma (million years ago). It is preceded by the Middle Triassic Epoch and followed by the Early Jurassic Epoch. The corresponding series (stratigraphy), series of rock beds is known as the Upper Triassic. The Late Triassic is divided into the Carnian, Norian and Rhaetian Geologic time scale, Ages. Many of the first dinosaurs evolved during the Late Triassic, including ''Plateosaurus'', ''Coelophysis'', and ''Eoraptor''. The Triassic–Jurassic extinction event began during this epoch and is one of the five major mass extinction events of the Earth. Etymology The Triassic was named in 1834 by Friedrich August von Namoh, Friedrich von Alberti, after a succession of three distinct rock layers (Greek meaning 'triad') that are widespread in southern Germany: the lower Buntsandstein (colourful sandstone'')'', t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alwalkeria
''Alwalkeria'' (; "for Alick Walker") is a genus partly based on basal saurischian dinosaur remains from the Late Triassic, living in India. A thighbone found indicates a small bipedal form. It has been seen as a chimera. Etymology This taxon was originally named ''Walkeria maleriensis'' by Sankar Chatterjee in 1987, in honor of British paleontologist Alick Walker. However, since the original generic name was found to be preoccupied by a bryozoan, the name ''Alwalkeria'' was created in 1994 by Chatterjee and Ben Creisler. The specific name ''maleriensis'' is a reference to the Maleri Formation, in southern India, where its fossils were found. Description The only known specimen, holotype ISI R306 is incomplete and consists of parts of the front ends of the upper and lower jaws, 28 incomplete vertebrae from all parts of the spinal column, most of a femur, and an astragalus (ankle bone). The partial skull is about 4 centimeters long (1.5 in). Although material of ''Alw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chilesaurus
''Chilesaurus'' is an extinct genus of herbivorous dinosaur. The type and only known species so far is ''Chilesaurus diegosuarezi''. ''Chilesaurus'' lived about 145 million years ago (Mya) in the Late Jurassic period of Chile. Showing a combination of traits from theropods, ornithischians, and sauropodomorphs, this genus has far-reaching implications for the evolution of dinosaurs, such as whether the traditional saurischian-ornithischian split is superior or inferior to the proposed group Ornithoscelida. Description ''Chilesaurus'' measured roughly from nose to tail. The holotype is a smaller individual of half that length. The most unusual feature of ''Chilesaurus'' is its spatula-shaped, elongated teeth, obliquely pointing forwards. Such dentition would be unique in the Theropoda, where it has sometimes been recovered, and is typical for a herbivore, indicating ''Chilesaurus'' was a plant-eater. Another adaptation for eating plants is the backward-pointing pubic bone in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chindesaurus
''Chindesaurus'' ( ) is an extinct genus of basal saurischian dinosaur from the Late Triassic (213-210 million years ago) of the southwestern United States. It is known from a single species, ''C. bryansmalli'', based on a partial skeleton recovered from Petrified Forest National Park in Arizona. The original specimen was nicknamed "Gertie", and generated much publicity for the park upon its discovery in 1984 and airlift out of the park in 1985. Other fragmentary referred specimens have been found in Late Triassic sediments throughout Arizona, New Mexico, and Texas, but these may not belong to the genus. ''Chindesaurus'' was a bipedal carnivore, approximately as large as a wolf.Holtz, Thomas R. Jr. (2012) ''Dinosaurs: The Most Complete, Up-to-Date Encyclopedia for Dinosaur Lovers of All Ages,'Winter 2011 Appendix./ref> ''Chindesaurus'''s classification is debated, and various papers have had different conclusions on its affinities. Its fossils were originally believed to belong to " ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Daemonosaurus
''Daemonosaurus'' is an extinct genus of possible theropod dinosaur from the Late Triassic of New Mexico. The only known fossil is a skull and neck fragments from deposits of the latest Triassic Chinle Formation at Ghost Ranch. ''Daemonosaurus'' was an unusual dinosaur with a short skull and large, fang-like teeth. It lived alongside early neotheropods such as ''Coelophysis'', which would have been among the most common dinosaurs by the end of the Triassic. However, ''Daemonosaurus'' retains several plesiomorphic ("primitive") traits of the snout, and it likely lies outside the clade Neotheropoda. It may be considered a late-surviving basal theropod or non-theropod basal saurischian, possibly allied to other early predatory dinosaurs such as herrerasaurids or '' Tawa''. Discovery ''Daemonosaurus'' is known from a single fossil, the holotype CM 76821, which consists of a skull, mandibles, an atlas bone, an axis bone, other neck vertebrae, and rib fragments. This specimen was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eodromaeus
''Eodromaeus'' (meaning "dawn runner") is an extinct genus of probable basal theropod dinosaurs from the Late Triassic of Argentina. Like many other of the earliest-known dinosaurs, it hails from the Carnian-age (~230 Ma) Ischigualasto Formation, within the Ischigualasto-Villa Unión Basin of northwestern Argentina. Upon its discovery, it was argued to be one of the oldest true theropods, supplanting its contemporary ''Eoraptor'', which was reinterpreted as a basal sauropodomorph.Martínez et al., 2011 Discovery Fossils from ''Eodromaeus'' were first discovered in 1996 by Argentinean paleontologist Ricardo N. Martinez and Earthwatch volunteer Jim Murphy, and it was first believed that the fossils were a new species of ''Eoraptor''. However, as the researchers started to take a closer look at the fossils, they found that it had many skeletal features which were absent in ''Eoraptor'', and they understood that it came from a new genus. ''Eodromaeus'' is known from six specimen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aves
Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweight skeleton. Birds live worldwide and range in size from the bee hummingbird to the ostrich. There are about ten thousand living species, more than half of which are passerine, or "perching" birds. Birds have whose development varies according to species; the only known groups without wings are the extinct moa and elephant birds. Wings, which are modified forelimbs, gave birds the ability to fly, although further evolution has led to the loss of flight in some birds, including ratites, penguins, and diverse endemic island species. The digestive and respiratory systems of birds are also uniquely adapted for flight. Some bird species of aquatic environments, particularly seabirds and some waterbirds, have further evolved for swimming. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nhandumirim
''Nhandumirim'' (meaning "small rhea" in the Tupi language) is a genus of basal sauropodomorph dinosaur from the Carnian age of Late Triassic Brazil. It is currently considered a saturnaliid sauropodomorph. The type and only species, ''Nhandumirim waldsangae,'' is known from a single immature specimen including vertebrae, a , pelvic material, and a hindlimb found in the Santa Maria Formation in Rio Grande do Sul. ''Nhandumirim'' is differentiated from other Santa Maria dinosaurs such as ''Staurikosaurus'' and ''Saturnalia'' on the basis of its more gracile, long-legged proportions and several more specific skeletal features. However, it is noteworthy that the holotype of ''Nhandumirim'' is an immature individual. Several features of the tibia led the describers of the genus and species to consider ''Nhandumirim'' ''waldsangae'' possibly the earliest theropod, but some analyses in their study offer alternative positions within Saurischia. All subsequent studies considered ''Nh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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