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Dinosaurian
Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is the subject of active research. They became the dominant terrestrial vertebrates after the Triassic–Jurassic extinction event 201.3 mya; their dominance continued throughout the Jurassic and Cretaceous periods. The fossil record shows that birds are feathered dinosaurs, having evolved from earlier 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 taxonomic, morphological and ecological standpoints. Birds, at over 10,700 living species ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theropoda
Theropoda (; ), whose members are known as theropods, is a dinosaur clade that is characterized by hollow bones and three toes and claws on each limb. Theropods are generally classed as a group of saurischian dinosaurs. They were ancestrally carnivorous, although a number of theropod groups evolved to become herbivores and omnivores. Theropods first appeared during the Carnian age of the late Triassic period 231.4 million years ago ( Ma) and included all the large terrestrial carnivores from the Early Jurassic until at least the close of the Cretaceous, about 66 Ma. In the Jurassic, birds evolved from small specialized coelurosaurian theropods, and are today represented by about 10,500 living species. Biology Diet and teeth Theropods exhibit a wide range of diets, from insectivores to herbivores and carnivores. Strict carnivory has always been considered the ancestral diet for theropods as a group, and a wider variety of diets was historically considered a characteris ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apatosaurus
''Apatosaurus'' (; meaning "deceptive lizard") is a genus of herbivorous sauropod dinosaur that lived in North America during the Late Jurassic period. Othniel Charles Marsh described and named the first-known species, ''A. ajax'', in 1877, and a second species, ''A. louisae'', was discovered and named by William H. Holland in 1916. ''Apatosaurus'' lived about 152 to 151 million years ago (mya), during the late Kimmeridgian to early Tithonian age, and are now known from fossils in the Morrison Formation of modern-day Colorado, Oklahoma, New Mexico, Wyoming, and Utah in the United States. ''Apatosaurus'' had an average length of , and an average mass of . A few specimens indicate a maximum length of 11–30% greater than average and a mass of approximately . The cervical vertebrae of ''Apatosaurus'' are less elongated and more heavily constructed than those of '' Diplodocus'', a diplodocid like ''Apatosaurus'', and the bones of the leg are much stockier despite being ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stegosauria
Stegosauria is a group of herbivorous ornithischian dinosaurs that lived during the Jurassic and early Cretaceous periods. Stegosaurian fossils have been found mostly in the Northern Hemisphere, predominantly in what is now North America, Europe, Africa, South America and Asia. Their geographical origins are unclear; the earliest unequivocal stegosaurian, '' Huayangosaurus taibaii'', lived in China. Stegosaurians were armored dinosaurs ( thyreophorans). Originally, they did not differ much from more primitive members of that group, being small, low-slung, running animals protected by armored scutes. An early evolutionary innovation was the development of spikes as defensive weapons. Later species, belonging to a subgroup called the Stegosauridae, became larger, and developed long hindlimbs that no longer allowed them to run. This increased the importance of active defence by the thagomizer, which could ward off even large predators because the tail was in a higher position, ... [...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] |
Pisanosaurus
''Pisanosaurus'' () is an extinct genus of early dinosauriform, likely an ornithischian or silesaurid, from the Late Triassic of Argentina. It was a small, lightly built, ground-dwelling herbivore, that could grow up to an estimated long. Only one species, the type, ''Pisanosaurus mertii'', is known, based on a single partial skeleton discovered in the Ischigualasto Formation of the Ischigualasto-Villa Unión Basin in northwestern Argentina. This part of the formation has been dated to the late Carnian, approximately 229 million years ago. Discovery and naming ''Pisanosaurus'' is known from a single fragmented skeleton discovered in 1962 by Galileo Juan Scaglia at the Hoyada del Cerro Las Lajas locality (also known as Agua de Las Catas) in the Ischigualasto Formation of La Rioja Province, Argentina. The genus is based on a specimen given the designation PVL 2577, which consists of a partial skull including a fragmentary right maxilla with teeth, and incomplete rig ... [...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 specim ... [...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 spe ... [...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 conside ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nyasasaurus
''Nyasasaurus'' (meaning " Lake Nyasa lizard") is an extinct genus of avemetatarsalian archosaur from the putatively Middle Triassic Manda Formation of Tanzania that may be the earliest known dinosaur. The type species ''Nyasasaurus parringtoni'' was first described in 1956 in the doctoral thesis of English paleontologist Alan J. Charig, but it was not formally described until 2013. Previously, the oldest record of dinosaurs was from Brazil and Argentina and dated back to the mid-late Carnian stage, about 233.23 to 231.4 million years ago. ''Nyasasaurus'' comes from a deposit formerly considered Anisian in age, meaning that it would predate other early dinosaurs by about 12 million years. However, more recent studies cast doubt to this age, pointing out that the deposits would actually be Carnian in age, which would considerably reduce this temporal gap. History of study In the 1930s, the holotype of ''Nyasasaurus'' was collected in Parrington's locality B36 from the Li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tawa Hallae
''Tawa'' (named after the Hopi word for the Puebloan sun god) is a genus of possible basal theropod dinosaurs from the Late Triassic period. The fossil remains of ''Tawa hallae'', the type and only species were found in the Hayden Quarry of Ghost Ranch, New Mexico, US. Its discovery alongside the relatives of '' Coelophysis ''and ''Herrerasaurus'' supports the hypothesis that the earliest dinosaurs arose in Gondwana during the early Late Triassic period in what is now South America, and radiated from there around the globe. The specific name honours Ruth Hall, founder of the Ghost Ranch Museum of Paleontology. Description ''Tawa'' was estimated to have been long as an adult, with a weight of . ''Tawa'' preserves characters that can be associated with different dinosaur taxa. Its skull morphology resembles that of coelophysoids and the ilium approximates that of a herrerasaurid. Like the coelophysoids, ''Tawa'' has a kink in its upper jaws, between the maxilla and the pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Smok (archosaur)
''Smok'' (meaning "dragon" in Polish) is an extinct genus of large carnivorous archosaur. It lived during the latest Triassic period (latest Norian to early Rhaetian stage, between 205–200 Ma). Its remains have been found in Lisowice, southern Poland. The only species is ''Smok wawelski'' (after the Wawel Dragon, a dragon from Polish folklore) and was named in 2012. It is larger than any other known predatory archosaur from the Late Triassic or Early Jurassic of central Europe. The relation of ''Smok'' to other archosaurs has not yet been thoroughly studied; it may be a rauisuchid, prestosuchid, an ornithosuchid pseudosuchian (part of the crocodilian lineage of archosaurs) or a theropod dinosaur (part of the bird/dinosaurian lineage of archosaurs). Description At an estimated in length, ''Smok'' was the largest carnivorous archosaur in central Europe in the time it was alive. It was larger than any other known theropod dinosaur or pseudosuchian living in cen ... [...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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
