[161] Other mass-death sites have been discovered subsequently. [239] In the 1970s, Ostrom revived the dinosaurbird theory,[240] which gained momentum in the coming decades with the advent of cladistic analysis,[241] and a great increase in the discovery of small theropods and early birds. "The assembly of the avian body plan: a 160-million-year long process" (PDF). Despite their unrefined methods, the contributions of Cope and Marsh to paleontology were vast: Marsh unearthed 86 new species of dinosaur and Cope discovered 56, a total of 142 new species. Early saurischians"lizard-hipped", from the Greek sauros () meaning "lizard" and ischion () meaning "hip joint"retained the hip structure of their ancestors, with a pubis bone directed cranially, or forward. [265] The ratio between egg volume and body mass of adults among these dinosaurs suggest that the eggs were primarily brooded by the male, and that the young were highly precocial, similar to many modern ground-dwelling birds. "And. [168], From a behavioral standpoint, one of the most valuable dinosaur fossils was discovered in the Gobi Desert in 1971. Matthew G. Baron; Megan E. Williams (2018). [324][325][326] The age estimates have also been considered unreliable. Such modifications, originating in the most recent common ancestor of a certain taxonomic group, are called the synapomorphies of such a group.[30]. Dinosaur legs extend directly beneath the body, whereas the legs of lizards and crocodilians sprawl out to either side. These include an elongated scapula, or shoulder blade; a sacrum composed of three or more fused vertebrae (three are found in some other archosaurs, but only two are found in Herrerasaurus);[10] and a perforate acetabulum, or hip socket, with a hole at the center of its inside surface (closed in Saturnalia tupiniquim, for example). Bones from several similar-sized individuals were incorporated into the skeleton now mounted and on display at the Museum fr Naturkunde in Berlin;[144] this mount is 12 meters (39ft) tall and 21.8 to 22.5 meters (72 to 74ft) long,[145][146] and would have belonged to an animal that weighed between 30000 and 60000kilograms (70000 and 130000lb). Last Thread Tools: Mar 22, 2016, 04:57 PM #1; tim hooper. [245] Direct fossil evidence of feathers or feather-like structures has been discovered in a diverse array of species in many non-avian dinosaur groups,[70] both among saurischians and ornithischians. It is the largest animal alive today. He was quoted as saying, "God created the sun, the stars, the heavens and the earth, and then made Adam and Eve. [267], All non-avian dinosaurs and most lineages of birds[268] became extinct in a mass extinction event, called the CretaceousPaleogene (K-Pg) extinction event, at the end of the Cretaceous period. [29], While recent discoveries have made it more difficult to present a universally agreed-upon list of their distinguishing features, nearly all dinosaurs discovered so far share certain modifications to the ancestral archosaurian skeleton, or are clearly descendants of older dinosaurs showing these modifications. A discovery of features in a Tyrannosaurus skeleton provided evidence of medullary bone in extinct dinosaurs and, for the first time, allowed paleontologists to establish the sex of a fossil dinosaur specimen. [193] Trackways have also confirmed parental behavior among ornithopods from the Isle of Skye in northwestern Scotland. [20] They have always been recognized as an extremely varied group of animals; over 900 non-avian dinosaur genera have been identified with certainty as of 2018, and the total number of genera preserved in the fossil record has been estimated at around 1850, nearly 75% of which remain to be discovered, and 1124 species by 2016. Adeopapposaurus - A close relative of Massospondylus. He published his findings in 1825. Complete nonsense) Another has his own YouTube Channel and say's that Yutyrannus and other feathered dinosaurs don't exist and are all made in China. Those, along with multiple trackways, suggest that gregarious behavior was common in many early dinosaur species. [320] In 2020, Alfio Chiarenza and colleagues suggested that the Deccan Traps may even have had the opposite effect: they suggested that the long-term warming caused by its carbon dioxide emissions may have dampened the impact winter from the Chicxulub impact. They first appeared during the Triassic period, between 245 and 233.23million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is a subject of active research. In addition, vocal communication in dinosaurs is indicated by the development of advanced hearing in nearly all major groups. [208][209] From the 1960s forward, Armand de Ricqls suggested that the presence of fibrolamellar bonebony tissue with an irregular, fibrous texture and filled with blood vesselswas indicative of consistently fast growth and therefore endothermy. [113] The Carnian-aged Chaares Formation of Argentina preserves primitive, dinosaur-like ornithodirans such as Lagosuchus and Lagerpeton in Argentina, making it another important site for understanding dinosaur evolution. Within the archosaur group, dinosaurs are differentiated most noticeably by their gait. Although known for large size, many Mesozoic dinosaurs were human-sized or smaller, and modern birds are generally small in size. Off Topic Discussion Life, The Universe, and Politics Discussion Proof that dinosaurs never existed! In subsequent decades, dinosaur exhibits opened at parks and museums around the world, ensuring that successive generations would be introduced to the animals in an immersive and exciting way. [66] Asian localities have produced the most complete theropod specimens,[68] while North American localities have produced the most complete sauropodomorph specimens. However, its known fossils are too fragmentary to identify it as a dinosaur or only a close relative. Roy. [27] Some are herbivorous, others carnivorous, including seed-eaters, fish-eaters, insectivores, and omnivores. [151][152] Other large carnivorous theropods included Giganotosaurus, Carcharodontosaurus and Tyrannosaurus. Better specimens also led to new species being invalidated less frequently. As a consequence, more sauropodomorphs were named between 1990 and 2020 than in all previous years combined. [30], Collectively, dinosaurs as a clade are divided into two primary branches, Saurischia and Ornithischia. [271][272] In all, approximately 47% of genera and 76% of species on Earth became extinct during the K-Pg extinction event. [228][229] However, at least some modern birds (such as hummingbirds) can be facultatively ammonotelic, excreting most of the nitrogenous wastes as ammonia. [148], There were larger dinosaurs, but knowledge of them is based entirely on a small number of fragmentary fossils. The entry of the word "dinosaur" into the common vernacular reflects the animals' cultural importance: in English, "dinosaur" is commonly used to describe anything that is impractically large, obsolete, or bound for extinction. [79][80] In living reptiles and mammals, pigment-storing cellular structures known as melanosomes are partially responsible for producing colouration. 2 3 Next. [273] The relatively large size of most dinosaurs and the low diversity of small-bodied dinosaur species at the end of the Cretaceous may have contributed to their extinction;[274] the extinction of the bird lineages that did not survive may also have been caused by a dependence on forest habitats or a lack of adaptations to eating seeds for survival. Samuel Beckles discovered a sauropod forelimb with preserved skin in 1852 that was incorrectly attributed to a crocodile; it was correctly attributed by Marsh in 1888 and subject to further study by Reginald Hooley in 1917. [323] However, these supposed Paleocene dinosaurs are considered by many other researchers to be reworked, that is, washed out of their original locations and then re-buried in younger sediments. [212][213] This has led to a significant body of work in reconstructing growth curves and modeling the evolution of growth rates across various dinosaur lineages,[214] which has suggested overall that dinosaurs grew faster than living reptiles. The large sizes of some dinosaurs, as well as their seemingly monstrous and fantastic nature, have ensured their regular appearance in best-selling books and films, such as Jurassic Park. In the northern continents of North America and Asia, the major theropods were tyrannosaurids and various types of smaller maniraptoran theropods, with a predominantly ornithischian herbivore assemblage of hadrosaurids, ceratopsians, ankylosaurids, and pachycephalosaurians. For example, as diapsids, dinosaurs ancestrally had two pairs of Infratemporal fenestrae (openings in the skull behind the eyes), and as members of the diapsid group Archosauria, had additional openings in the snout and lower jaw. Dinosaur eggs were usually laid in a nest. In birds, the larynx plays no role in sound production. 58 Comments on Dinosaurs Never Existed! In 1896, Marsh calculated ratios between brain weight and body weight of seven species of dinosaurs, showing that the brain of dinosaurs was proportionally smaller than in today's crocodiles, and that the brain of Stegosaurus was smaller than in any living land vertebrate. Dinosaur Videos: 12 dinosaur myths that will blow your mind Knowledge about dinosaurs is derived from a variety of fossil and non-fossil records, including fossilized bones, feces, trackways, gastroliths, feathers, impressions of skin, internal organs and other soft tissues. thanks for watchinghttp://gvenews.com/the-dinosaurs-never-existed-bones-and-fossils-manmade/http://en.wikipedia.org/wiki/Archaeoraptor [270] In 1984, Dale Russell carried out an analysis to account for these biases, and found no evidence of a decline;[279] another analysis by David Fastovsky and colleagues in 2004 even showed that dinosaur diversity continually increased until the extinction,[280] but this analysis has been rebutted. [105], The Ischigualasto Formation (radiometrically dated at 231-230 million years old[106]) has produced the early saurischian Eoraptor, originally considered a member of the Herrerasauridae[107] but now considered to be an early sauropodomorph, along with the herrerasaurids Herrerasaurus and Sanjuansaurus, and the sauropodomorphs Chromogisaurus, Eodromaeus, and Panphagia. [17] Other prehistoric animals, including pterosaurs, mosasaurs, ichthyosaurs, plesiosaurs, and Dimetrodon, while often popularly conceived of as dinosaurs, are not taxonomically classified as dinosaurs. Dinosaur - Wikipedia Dinosaurs That May Never Have Actually Existed - Grunge [121] Ankylosaurians and ornithopods were also becoming more common, but primitive sauropodomorphs had become extinct. Dinosaurs Never Existed - Question EVERYTHING - unshackledminds.com It is considered a transitional fossil, in that it displays features of both groups. [288] Shocked quartz, indicative of a strong shockwave emanating from an impact, was also found worldwide. Evolution and Dinosaurs Debunked; Wiki Sections (0) FrontPage (1) Earth (2) Space (3) Science (4) History (5) Society (6) Disinformation Recent Changes. At the same time, several groups of dinosaurian herbivores evolved more sophisticated ways to orally process food. [135][136] Two topics of particular interest and study have been dinosaur size and behavior. Brontosaurus (/ b r n t s r s /; meaning "thunder lizard" from Greek , bront "thunder" and , sauros "lizard") is a genus of gigantic quadruped sauropod dinosaurs.Although the type species, B. excelsus, had long been considered a species of the closely related Apatosaurus and therefore invalid, researchers proposed in 2015 that Brontosaurus is a . 65 million years ago marks the end of the Cretaceous Period, and is when dinosaurs go extinct. Top Ten Scientific Flaws In The Theory of Prehistoric Dinosaurs [70][14] Birds share over a hundred distinct anatomical features with theropod dinosaurs, which are now generally accepted to have been their closest ancient relatives. Apatosaurus - Wikipedia [122] The general homogeneity of dinosaurian faunas continued into the Middle and Late Jurassic, where most localities had predators consisting of ceratosaurians, megalosauroids, and allosauroids, and herbivores consisting of stegosaurian ornithischians and large sauropods. In addition, the cartilages were ossified, implying that laryngeal ossification is a feature of some non-avian dinosaurs. The famous triceratops dinosaur never actually existed as a separate dinosaur species, paleontologists say. [32] Additionally, several characteristics once thought to be synapomorphies are now known to have appeared before dinosaurs, or were absent in the earliest dinosaurs and independently evolved by different dinosaur groups. Beginning in 1852 with a passing mention in Charles Dickens' Bleak House,[331] dinosaurs have been featured in large numbers of fictional works. What about all the Pictures of the Earth? [25][26] In 2021, the number of modern-day birds (avian dinosaurs) was estimated to be at 10,806 species. These were later supplemented or replaced in Africa by large spinosaurid and carcharodontosaurid theropods, and rebbachisaurid and titanosaurian sauropods, also found in South America. [125], The surviving lineages of neornithine birds, including the ancestors of modern ratites, ducks and chickens, and a variety of waterbirds, diversified rapidly at the beginning of the Paleogene period, entering ecological niches left vacant by the extinction of Mesozoic dinosaur groups such as the arboreal enantiornithines, aquatic hesperornithines, and even the larger terrestrial theropods (in the form of Gastornis, eogruiids, bathornithids, ratites, geranoidids, mihirungs, and "terror birds"). Despite the terms "bird hip" (Ornithischia) and "lizard hip" (Saurischia), birds are not part of Ornithischia. [13] Birds are classified as belonging to the subgroup Maniraptora, which are coelurosaurs, which are theropods, which are saurischians, which are dinosaurs. In 2021, the best preserved specimen of a dinosaur's cloacal vent exterior was described for Psittacosaurus, demonstrating lateral swellings similar to crocodylian musk glands used in social displays by both sexes and pigmented regions which could also reflect a signalling function. [204] Evidence from crocodiles and their extinct relatives suggests that such elevated metabolisms could have developed in the earliest archosaurs, which were the common ancestors of dinosaurs and crocodiles. Most research conducted since the 1970s, however, has indicated that dinosaurs were active animals with elevated metabolisms and numerous adaptations for social interaction. "THE DINOSAURS NEVER EXISTED" - YouTube [245] Research into the genetics of American alligators has revealed that crocodylian scutes do possess feather-keratins during embryonic development, but these keratins are not expressed by the animals before hatching. They resurrected the clade Ornithoscelida to refer to the group containing Ornithischia and Theropoda. 30 Apr 2023 07:02:32 Timeline of major dinosaur groups per Holtz (2007). Through the first half of the 20th century, before birds were recognized as dinosaurs, most of the scientific community believed dinosaurs to have been sluggish and cold-blooded. [56] Owen recognized that the remains that had been found so far, Iguanodon, Megalosaurus and Hylaeosaurus, shared distinctive features, and so decided to present them as a distinct taxonomic group. [7][8] With the backing of Prince Albert, the husband of Queen Victoria, Owen established the Natural History Museum, London, to display the national collection of dinosaur fossils and other biological and geological exhibits. Dinosaurs: Science or Science Fiction? This was a revolutionary discovery as, until that point, most scientists had believed dinosaurs walked on four feet, like other lizards. [285][286], The bolide impact hypothesis, first brought to wide attention in 1980 by Walter Alvarez, Luis Alvarez, and colleagues, attributes the K-Pg extinction event to a bolide (extraterrestrial projectile) impact. Your Favorite Dinosaur Never Even Existed, Says Jurassic World Scientist [42], Scholarly descriptions of what would now be recognized as dinosaur bones first appeared in the late 17th century in England. [91][92][93] However, in 2005, Schweitzer and colleagues reported that a femur of Tyrannosaurus preserved soft, flexible tissue within, including blood vessels, bone matrix, and connective tissue (bone fibers) that had retained their microscopic structure. A detailed assessment of archosaur interrelations by Sterling Nesbitt[31] confirmed or found the following twelve unambiguous synapomorphies, some previously known: Nesbitt found a number of further potential synapomorphies and discounted a number of synapomorphies previously suggested. Conifers and pteridophytes were the most common plants. [59], World War II caused a pause in palaeontological research; after the war, research attention was also diverted increasingly to fossil mammals rather than dinosaurs, which were seen as sluggish and cold-blooded. The structure was composed of cricoid and arytenoid cartilages, similar to those of non-avian reptiles. Dinosaur fossils with scaly skin impressions have been found since the 19th century. Anatomically, these two groups can be distinguished most noticeably by their pelvic structure. Acrotholus - North America's earliest bone-headed dinosaur. This video will reveal one of the greatest hoaxes in human history. [260], Large meat-eating dinosaurs had a complex system of air sacs similar to those found in modern birds, according to a 2005 investigation led by Patrick M. O'Connor. [277] It remains uncertain whether the diversity of dinosaurs was in gradual decline before the K-Pg extinction event, or whether dinosaurs were actually thriving prior to the extinction. [164] The interpretation of dinosaurs as gregarious has also extended to depicting carnivorous theropods as pack hunters working together to bring down large prey. [135], The first potential evidence for herding or flocking as a widespread behavior common to many dinosaur groups in addition to birds was the 1878 discovery of 31Iguanodon, ornithischians that were then thought to have perished together in Bernissart, Belgium, after they fell into a deep, flooded sinkhole and drowned. This definition includes major groups such as ankylosaurians (armored herbivorous quadrupeds), stegosaurians (plated herbivorous quadrupeds), ceratopsians (bipedal or quadrupedal herbivores with neck frills), pachycephalosaurians (bipedal herbivores with thick skulls), ornithopods (bipedal or quadrupedal herbivores including "duck-bills"), theropods (mostly bipedal carnivores and birds), and sauropodomorphs (mostly large herbivorous quadrupeds with long necks and tails). Trackways of hundreds or even thousands of herbivores indicate that duck-billed (hadrosaurids) may have moved in great herds, like the American bison or the African springbok. Several deinonychosaur and oviraptorosaur specimens have also been found preserved on top of their nests, likely brooding in a bird-like manner. [322] Other evidence includes the presence of dinosaur remains in the Hell Creek Formation up to 1.3m (4.3ft) above the CretaceousPaleogene boundary, representing 40,000 years of elapsed time. But what I learn now is that the Troodon never existed. [18] Pterosaurs are distantly related to dinosaurs, being members of the clade Ornithodira. [303][304] Greenhouse gases such as carbon dioxide and sulfur dioxide would have been released by this volcanic activity,[305][306] resulting in climate change through temperature perturbations of roughly 3C (5.4F) but possibly as high as 7C (13F). [170] Additional evidence for attacking live prey is the partially healed tail of an Edmontosaurus, a hadrosaurid dinosaur; the tail is damaged in such a way that shows the animal was bitten by a tyrannosaur but survived. The largest ornithischian dinosaur was probably the hadrosaurid Shantungosaurus giganteus which measured 16.6 meters (54ft). Dinosaurs are a diverse group of reptiles [note 1] of the clade Dinosauria. Dinosaurs in China show some differences, with specialized metriacanthosaurid theropods and unusual, long-necked sauropods like Mamenchisaurus. Single-task at best. [276], At the time of the K-Pg extinction, the Deccan Traps flood basalts of India were actively erupting. [292][293][294], Within hours, the Chicxulub impact would have created immediate effects such as earthquakes,[295] tsunamis,[296] and a global firestorm that likely killed unsheltered animals and started wildfires. [121] Gymnosperm plants (particularly conifers), a potential food source, radiated in the Late Triassic. Humans are a young species when compared with dinosaurs. Persistent public enthusiasm for the animals has resulted in significant funding for dinosaur science, and new discoveries are regularly covered by the media. [60] Concurrently, Robert T. Bakker published a series of studies that likewise argued for active lifestyles in dinosaurs based on anatomical and ecological evidence (see Physiology),[63][64] which were subsequently summarized in his 1986 book The Dinosaur Heresies. They also contend that the causes of different mass extinctions should be assessed separately. [222] Such respiratory systems, which may have appeared in the earliest saurischians,[223] would have provided them with more oxygen compared to a mammal of similar size, while also having a larger resting tidal volume and requiring a lower breathing frequency, which would have allowed them to sustain higher activity levels. Thanks to museums, books, and pop culture, dinosaurs remain larger-than-life. The React team investigates as conspiracists take to social media to dispel dinosaurs' existence Though the first dinosaurs appeared about 243 million years ago, they remain as prominent as ever today. [88][89] More concrete evidence of internal anatomy has been reported in Scipionyx from the Pietraroja Plattenkalk of Italy. [10] It has also been suggested that Dinosauria be defined with respect to the MRCA of Megalosaurus and Iguanodon, because these were two of the three genera cited by Richard Owen when he recognized the Dinosauria. [7][8][9] Since then, mounted fossil dinosaur skeletons have been major attractions at museums worldwide, and dinosaurs have become an enduring part of popular culture. The earliest part of this time saw the spread of ankylosaurians, iguanodontians, and brachiosaurids through Europe, North America, and northern Africa. Elaborate display structures such as horns or crests are common to all dinosaur groups, and some extinct groups developed skeletal modifications such as bony armor and spines. [38] Erect limbs probably also helped support the evolution of large size by reducing bending stresses on limbs. [108][114] Dinosaurs may have appeared as early as the Anisian epoch of the Triassic, approximately 245million years ago, which is the age of Nyasasaurus from the Manda Formation of Tanzania. [134] Further details and other hypotheses of classification may be found on individual articles. The release of the first and second editions of The Dinosauria in 1990 and 2004, and of a review paper by Paul Sereno in 1998, were accompanied by increases in the number of published phylogenetic trees for dinosaurs. That is why they indoctrinate the young with love of dinosaurs and books and movies etc. Saurischia includes the theropods (exclusively bipedal and with a wide variety of diets) and sauropodomorphs (long-necked herbivores which include advanced, quadrupedal groups).[29][133]. Across theropods, sauropodomorphs, and ornithischians, the number of named genera began to increase exponentially in the 1990s. [143], The tallest and heaviest dinosaur known from good skeletons is Giraffatitan brancai (previously classified as a species of Brachiosaurus). The other groups mentioned are, like dinosaurs and pterosaurs, members of Sauropsida (the reptile and bird clade), except Dimetrodon (which is a synapsid). Aetonyx - possible junior synonym of Massospondylus. Many of these specimens were unearthed in the lagersttten of the Jehol Biota. Birds are thus considered to be dinosaurs and dinosaurs are, therefore, not extinct. Adamantisaurus - This titanosaur was named 50 years after its discovery. Eric Dubay: Dinosaurs Never Existed! - YouTube [14][248] Feather-like structures known as pycnofibres have also been found in pterosaurs. [108] Eoraptor's likely resemblance to the common ancestor of all dinosaurs suggests that the first dinosaurs would have been small, bipedal predators. [187] Some species of modern bird have no nests; the cliff-nesting common guillemot lays its eggs on bare rock, and male emperor penguins keep eggs between their body and feet. Archosaurian reptiles that dominated the Mesozoic Era, Dinosaurs (including birds) are members of the. [122], The CretaceousPaleogene extinction event, which occurred approximately 66million years ago at the end of the Cretaceous, caused the extinction of all dinosaur groups except for the neornithine birds. It preserves portions of the intestines, colon, liver, muscles, and windpipe. [11] Both definitions result in the same set of animals being defined as dinosaurs: "Dinosauria = Ornithischia + Saurischia". [73] Fossils of keratin-based skin coverings or bony skin coverings are known from most major groups of dinosaurs. [122] Another notable evolutionary event of the Jurassic was the appearance of true birds, descended from maniraptoran coelurosaurians. [294], Non-avian dinosaur remains have occasionally been found above the K-Pg boundary. [10], A variety of other skeletal features are shared by dinosaurs. [202] An emerging consensus among researchers is that, while different lineages of dinosaurs would have had different metabolisms, most of them had higher metabolic rates than other reptiles but lower than living birds and mammals,[203] which is termed mesothermy by some.
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