dinosaurs never existed wiki

Conifers and pteridophytes were the most common plants. [102], Dinosaurs diverged from their archosaur ancestors during the Middle to Late Triassic epochs, roughly 20million years after the devastating PermianTriassic extinction event wiped out an estimated 96% of all marine species and 70% of terrestrial vertebrate species approximately 252million years ago. Because the line of dinosaurs that includes Allosaurus and Tyrannosaurus diverged from the line that led to Tenontosaurus very early in the evolution of dinosaurs, this suggests that the production of medullary tissue is a general characteristic of all dinosaurs. [140], The sauropods were the largest and heaviest dinosaurs. [21][22][23] A 1995 study predicted that about 3,400 dinosaur genera ever existed, including many that would not have been preserved in the fossil record. [42], Scholarly descriptions of what would now be recognized as dinosaur bones first appeared in the late 17th century in England. Evidence suggests that all dinosaurs were egg-laying, and that nest-building was a trait shared by many dinosaurs, both avian and non-avian. Diplodocus (/ d p l d k s /, / d a p l d k s /, or / d p l o d o k s /) was a genus of diplodocid sauropod dinosaurs, whose fossils were first discovered in 1877 by S. W. Williston.The generic name, coined by Othniel Charles Marsh in 1878, is a neo-Latin term derived from Greek (diplos) "double" and (dokos) "beam", in . The eruptions can be separated into three phases around the K-Pg boundary, two prior to the boundary and one after. (Although fossils had been found before, their nature had not been correctly discerned.) Dinosaurs in China show some differences, with specialized metriacanthosaurid theropods and unusual, long-necked sauropods like Mamenchisaurus. Such modifications, originating in the most recent common ancestor of a certain taxonomic group, are called the synapomorphies of such a group.[30]. Birds, at over 10,700 living species, are among the most diverse groups of vertebrates. . Dinosaurs That May Never Have Actually Existed - Grunge Dinosaurs are big and impressive megafauna. Images of Earth from Space are Fake Sep. 07, 2022. [159][160], Many modern birds are highly social, often found living in flocks. Head wounds from bites suggest that theropods, at least, engaged in active aggressive confrontations. [271][272][278] However, these comparisons did not account either for varying preservation potential between rock units or for different extents of exploration and excavation. ", "How many dinosaur species were there? However, the mobile cricoid-arytenoid joint and long arytenoid cartilages would have allowed for air-flow control similar to that of birds, and thus could have made bird-like vocalizations. There is general agreement that some behaviors that are common in birds, as well as in crocodiles (closest living relatives of birds), were also common among extinct dinosaur groups. We have an over 50% complete Allosaurus skeleton in our Creation Museum, dug out of the ground in northwestern Colorado. [184] The crests of some hadosaurids and the nasal chambers of ankylosaurids have been suggested to have functioned in acoustic resonance. [14], Research by Matthew G. Baron, David B. Norman, and Paul M. Barrett in 2017 suggested a radical revision of dinosaurian systematics. List of dinosaurs - Simple English Wikipedia, the free encyclopedia 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. [66] At least sauropodomorphs experienced a further increase in the number of named species in the 2010s, with an average of 9.3 new species having been named each year between 2009 and 2020. [270] Alongside dinosaurs, many other groups of animals became extinct: pterosaurs, marine reptiles such as mosasaurs and plesiosaurs, several groups of mammals, ammonites (nautilus-like mollusks), rudists (reef-building bivalves), and various groups of marine plankton. 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. These stones are swallowed by animals to aid digestion and break down food and hard fibers once they enter the stomach. Although some later groups of dinosaurs featured further modified versions of these traits, they are considered typical for Dinosauria; the earliest dinosaurs had them and passed them on to their descendants. [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. Large animals are more efficient at digestion than small animals, because food spends more time in their digestive systems. [53][55] Though the taxonomic name has often been interpreted as a reference to dinosaurs' teeth, claws, and other fearsome characteristics, Owen intended it also to evoke their size and majesty. These ornithodirans support the model of early dinosaurs as small, bipedal predators. [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. [24], In 2016, the estimated number of dinosaur species that existed in the Mesozoic was 1,5432,468. 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 . Primitive birds and many non-avialan dinosaurs often lay eggs in communal nests, with males primarily incubating the eggs. While dinosaurs were ancestrally bipedal (as are all modern birds), some prehistoric species were quadrupeds, and others, such as Anchisaurus and Iguanodon, could walk just as easily on two or four legs. Rebuilding a complete skeleton by comparing the size and morphology of bones to those of similar, better-known species is an inexact art, and reconstructing the muscles and other organs of the living animal is, at best, a process of educated guesswork. 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. [312] Since then, however, most researchers have adopted a more moderate position, which identifies the Chicxulub impact as the primary progenitor of the extinction while also recognizing that the Deccan Traps may also have played a role. Fibrolamellar bone was common in both dinosaurs and pterosaurs,[210][211] though not universally present. [12], Birds are now recognized as being the sole surviving lineage of theropod dinosaurs. Dinosaurs can therefore be divided into avian dinosaursbirdsand the extinct non-avian dinosaurs, which are all dinosaurs other than birds. [289] The actual impact site remained elusive until a crater measuring 180km (110mi) wide was discovered in the Yucatn Peninsula of southeastern Mexico, and was publicized in a 1991 paper by Alan Hildebrand and colleagues. Humans are a young species when compared with dinosaurs. [327], By human standards, dinosaurs were creatures of fantastic appearance and often enormous size. [135][136] Two topics of particular interest and study have been dinosaur size and behavior. [90][94] Many fields of study contribute to our understanding of dinosaurs, including physics (especially biomechanics), chemistry, biology, and the Earth sciences (of which paleontology is a sub-discipline). [90], Concurrently, a line of work led by Mary Higby Schweitzer, Jack Horner, and colleagues reported various occurrences of preserved soft tissues and proteins within dinosaur bone fossils. Timeline of major dinosaur groups per Holtz (2007). [228][229] However, at least some modern birds (such as hummingbirds) can be facultatively ammonotelic, excreting most of the nitrogenous wastes as ammonia. [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. This was a revolutionary discovery as, until that point, most scientists had believed dinosaurs walked on four feet, like other lizards. [38] Erect limbs probably also helped support the evolution of large size by reducing bending stresses on limbs. [157][158] The smallest herbivorous non-avialan dinosaurs included Microceratus and Wannanosaurus, at about 60 centimeters (2.0ft) long each. Aerosteon. [66] Asian localities have produced the most complete theropod specimens,[68] while North American localities have produced the most complete sauropodomorph specimens. [269][270][309], Before 2000, arguments that the Deccan Traps eruptionsas opposed to the Chicxulub impactcaused the extinction were usually linked to the view that the extinction was gradual. [105], Less well-preserved remains of the sauropodomorphs Jaklapallisaurus and Nambalia, along with the early saurischian Alwalkeria, are known from the Upper Maleri and Lower Maleri Formations of India. [259], Because feathers are often associated with birds, feathered dinosaurs are often touted as the missing link between birds and dinosaurs. [288] Shocked quartz, indicative of a strong shockwave emanating from an impact, was also found worldwide. Dinosaurs are a diverse group of reptiles[note 1] of the clade Dinosauria. Saurischia includes those taxa sharing a more recent common ancestor with birds than with Ornithischia, while Ornithischia includes all taxa sharing a more recent common ancestor with Triceratops than with Saurischia. Jack Horner's 1978 discovery of a Maiasaura ("good mother lizard") nesting ground in Montana demonstrated that parental care continued long after birth among ornithopods. This was one of the seminal results that led to the dinosaur renaissance. [86][87]) Stomach contents in some Jehol and Yanliao dinosaurs closely related to birds have also provided indirect indications of diet and digestive system anatomy (e.g., crops). Did Dinosaurs Actually Exist? | Answers in Genesis [156] The smallest known non-avialan dinosaurs were about the size of pigeons and were those theropods most closely related to birds. [43][50] The second non-avian dinosaur genus to be identified, Iguanodon, was discovered in 1822 by Mary Ann Mantell the wife of English geologist Gideon Mantell. Agnosphitys - a silesaurid dinosauromorph. [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. . It is the largest animal alive today. [39] Some non-dinosaurian archosaurs, including rauisuchians, also had erect limbs but achieved this by a "pillar-erect" configuration of the hip joint, where instead of having a projection from the femur insert on a socket on the hip, the upper pelvic bone was rotated to form an overhanging shelf. [189], Another widespread trait among modern birds (but see below in regards to fossil groups and extant megapodes) is parental care for young after hatching. [271][272] In all, approximately 47% of genera and 76% of species on Earth became extinct during the K-Pg extinction event. [28] Modern birds inhabit most available habitats, from terrestrial to marine, and there is evidence that some non-avian dinosaurs (such as Microraptor) could fly or at least glide, and others, such as spinosaurids, had semiaquatic habits. Sauropods, like earlier sauropodomorphs, were not oral processors, but ornithischians were evolving various means of dealing with food in the mouth, including potential cheek-like organs to keep food in the mouth, and jaw motions to grind food. Many people believe that mammals never co-existed with dinosaurs and evolved after the non-avian dinosaurs went extinct 65 million years ago. One example is a site in Inner Mongolia that has yielded remains of over 20 Sinornithomimus, from one to seven years old. [225][226] Sauropods may also have benefitted from their sizetheir small surface area to volume ratio meant that they would have been able to thermoregulate more easily, a phenomenon termed gigantothermy. [141] There are several proposed advantages for the large size of sauropods, including protection from predation, reduction of energy use, and longevity, but it may be that the most important advantage was dietary. [182], In 2023, a fossilized larynx was described from a specimen of the ankylosaurid Pinacosaurus. Cranial modifications like horns and crests are common dinosaurian traits, and some extinct species had bony armor. [76], Starting from the 1990s, major discoveries of exceptionally preserved fossils in deposits known as conservation Lagersttten contributed to research on dinosaur soft tissues. 10 Reasons Dinosaurs never existed : r/conspiracy - Reddit At the same time, several groups of dinosaurian herbivores evolved more sophisticated ways to orally process food. [177], Modern birds are known to communicate using visual and auditory signals, and the wide diversity of visual display structures among fossil dinosaur groups, such as horns, frills, crests, sails, and feathers, suggests that visual communication has always been important in dinosaur biology. Soc. [317][318] They consider the Chicxulub impact to have worsened the ongoing climate change caused by the eruptions. Did all the dinosaurs live together, and at the same time? The scientists conclude that three known species of Brontosaurus exist: Brontosaurus excelsus, the first discovered, as well as B. parvus and B. yahnahpin. In birds, the larynx plays no role in sound production. The first dinosaur fossils were recognized in the early 19th century, with the name "dinosaur" (meaning "terrible lizard") being coined by Sir Richard Owen in 1842 to refer to these "great fossil lizards". They first appeared during the Triassic period, between 243 and 233.23 million years ago, although the exact origin and. The nature of the event that caused this mass extinction has been extensively studied since the 1970s, leading to the development of two mechanisms that are thought to have played major roles: an extraterrestrial impact event in the Yucatn Peninsula, along with flood basalt volcanism in India. Many of these specimens were unearthed in the lagersttten of the Jehol Biota. Several deinonychosaur and oviraptorosaur specimens have also been found preserved on top of their nests, likely brooding in a bird-like manner. Eric Dubay: Dinosaurs Never Existed! - YouTube 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). Afromimus. Why do people think dinosaurs are a myth? - Raven Report [148], There were larger dinosaurs, but knowledge of them is based entirely on a small number of fragmentary fossils. [209] Other lines of evidence suggesting endothermy include the presence of feathers and other types of body coverings in many lineages (see Feathers); more consistent ratios of the isotope oxygen-18 in bony tissue compared to ectotherms, particularly as latitude and thus air temperature varied, which suggests stable internal temperatures[215][216] (although these ratios can be altered during fossilization[217]); and the discovery of polar dinosaurs, which lived in Australia, Antarctica, and Alaska when these places would have had cool, temperate climates. Giant prehistoric mammals such as Paraceratherium (the largest land mammal ever) were dwarfed by the giant sauropods, and only modern whales approach or surpass them in size. [44] He correctly identified the bone as the lower extremity of the femur of a large animal, and recognized that it was too large to belong to any known species. [40] Villagers in central China have long unearthed fossilized "dragon bones" for use in traditional medicines. [150], The largest carnivorous dinosaur was Spinosaurus, reaching a length of 12.6 to 18 meters (41 to 59ft), and weighing 7 to 20.9 metric tons (7.7 to 23.0 short tons). Harry Jerison, in 1973, showed that proportionally smaller brains are expected at larger body sizes, and that brain size in dinosaurs was not smaller than expected when compared to living reptiles. Not true. In addition, the cartilages were ossified, implying that laryngeal ossification is a feature of some non-avian dinosaurs. Various researchers have supported dinosaurs as being endothermic, ectothermic ("cold-blooded"), or somewhere in between. [139] This contrasts sharply with the average size of Cenozoic mammals, estimated by the National Museum of Natural History as about 2 to 5kg (4.4 to 11.0lb). That said, dinosaurs would have some advantages over mammal megafauna that would probably help them avoid being wiped out quite so easily. It's impossible that dinosaurs existed because dinosaurs are too big? [58], Dinosaur mania was exemplified by the fierce rivalry between Edward Drinker Cope and Othniel Charles Marsh, both of whom raced to be the first to find new dinosaurs in what came to be known as the Bone Wars. Many dinosaurs were quite small, some measuring about 50 centimeters (20 inches) in length. Any proper look at the facts will reveal that dinosaurs simply never existed. Regardless, dinosaurs existed alongside non-dinosaurian ornithodirans for a period of time, with estimates ranging from 510 million years[116] to 21 million years. [314] Combined with mathematical modelling of the seismic waves that would have been generated by the impact, this has led to the suggestion that the Chicxulub impact may have triggered these eruptions by increasing the permeability of the mantle plume underlying the Deccan Traps. A compilation of dinosaur skeletons. [81][82] Both chemical traces of melanin and characteristically-shaped melanosomes have been reported from feathers and scales of Jehol and Yanliao dinosaurs, including both theropods and ornithischians. Dinosaurs are varied from taxonomic, morphological and ecological standpoints. For much of the dinosaur era, the smallest sauropods were larger than anything else in their habitat, and the largest was an order of magnitude more massive than anything else that has since walked the Earth. [266], Some dinosaurs are known to have used gizzard stones like modern birds. In 1972, Bakker expanded on his arguments based on energy requirements and predator-prey ratios. [51][52], The study of these "great fossil lizards" soon became of great interest to European and American scientists, and in 1842 the English paleontologist Sir Richard Owen coined the term "dinosaur", using it to refer to the "distinct tribe or sub-order of Saurian Reptiles" that were then being recognized in England and around the world. The course "Dinosauria" was originally specified by "Sir" Richard Owen of the Royal Culture, and Superintendent of the British Museum Natural History Department in 1842. [238] However, as later discoveries showed, clavicles (or a single fused wishbone, which derived from separate clavicles) were not actually absent;[14] they had been found as early as 1924 in Oviraptor, but misidentified as an interclavicle. Aetonyx - possible junior synonym of Massospondylus. [164] The interpretation of dinosaurs as gregarious has also extended to depicting carnivorous theropods as pack hunters working together to bring down large prey. [330], The popular preoccupation with dinosaurs has ensured their appearance in literature, film, and other media. Dinosaur is a term which is defined as a terrestrial reptile with one of two possible hip structures. Now more detailed research over the last 10 years has shown that . Its remains were discovered in Tanzania between 1907 and 1912. Some were herbivorous, others carnivorous. Bollettino della Societ Paleontologica Italiana. Agrosaurus - probably a junior synonym of Thecodontosaurus. Agilisaurus. [165][166] However, this lifestyle is uncommon among modern birds, crocodiles, and other reptiles, and the taphonomic evidence suggesting mammal-like pack hunting in such theropods as Deinonychus and Allosaurus can also be interpreted as the results of fatal disputes between feeding animals, as is seen in many modern diapsid predators. [73] Later, in 2009, Schweitzer and colleagues reported that a Brachylophosaurus femur preserved similar microstructures, and immunohistochemical techniques (based on antibody binding) demonstrated the presence of proteins such as collagen, elastin, and laminin. For examples of this work conducted on different dinosaur lineages, see, Natural History Museum of Los Angeles County, British Association for the Advancement of Science, CretaceousPaleogene (K-Pg) extinction event, Lists of dinosaur-bearing stratigraphic units, "Two New Species of Large Predatory Dinosaur With Crocodile-Like Skulls Discovered on Isle of Wight", "The origin and early evolution of birds: discoveries, disputes, and perspectives from fossil evidence", "Paleontology and Geology of the Upper Jurassic Morrison Formation", New Mexico Museum of Natural History and Science, "Report on British Fossil Reptiles. 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. I used to believe in dinosaurs. Potato-of-All-Trades 2 yr. ago B r u h Ray-Misuto 2 yr. ago 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). This assemblage is interpreted as a social group that was trapped in mud. Dinosaurs evolved and then became extinct long before man walked the Earth.245 mya (million years ago) dinosaurs evolved.208 mya birds evolved.65 mya dinosaurs became extinct.80 thousand years ago . Brought to light just two years after Charles Darwin's seminal On the Origin of Species (1859), its discovery spurred the nascent debate between proponents of evolutionary biology and creationism. Did Humans Live With Dinosaurs? - AZ Animals [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"). Dinosaur Hoax - Dinosaurs Never Existed! - The Greatest Deception In As clarified by British geologist and historian Hugh Torrens, Owen had given a presentation about fossil reptiles to the British Association for the Advancement of Science in 1841, but reports of the time show that Owen did not mention the word "dinosaur", nor recognize dinosaurs as a distinct group of reptiles in his address. For example, studies of the forces exerted by muscles and gravity on dinosaurs' skeletal structure have investigated how fast dinosaurs could run,[135] whether diplodocids could create sonic booms via whip-like tail snapping,[176] and whether sauropods could float. [63][64][60][207], One of the greatest contributions to the modern understanding of dinosaur physiology has been paleohistology, the study of microscopic tissue structure in dinosaurs. What about all the Pictures of the Earth? [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. [174] While some early bird-like species may have already been arboreal as well (including dromaeosaurids) such as Microraptor[175]) most non-avialan dinosaurs seem to have relied on land-based locomotion. TIL: The Troodon never existed, it is now the Latenivenatrix - Reddit Dinosaurs are another recreation of history to promote the big bang evolution teaching. Some other diapsid groups, including crocodilians, dyrosaurs, sebecosuchians, turtles, lizards, snakes, sphenodontians, and choristoderans, also survived the event. Theropods were also radiating as herbivores or omnivores, with therizinosaurians and ornithomimosaurians becoming common. Roy. [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. [178] Other researchers have countered that vocalizations also exist in turtles, the closest relatives of archosaurs, suggesting that the trait is ancestral to their lineage. CT scanning of Aerosteon's fossil bones revealed evidence for the existence of air sacs within the animal's body cavity. 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 CretaceousPaleogene extinction event approximately 66mya. [283][284] End-Cretaceous trends in diversity may have varied between dinosaur lineages: it has been suggested that sauropods were not in decline, while ornithischians and theropods were in decline. Acta Palaeontologica Polonica. [110] Predatory theropod dinosaurs, which occupied most terrestrial carnivore niches during the Mesozoic, most often fall into the 100 to 1000kg (220 to 2200lb) category when sorted by estimated weight into categories based on order of magnitude, whereas recent predatory carnivoran mammals peak in the 10 to 100kg (22 to 220lb) category. 30 Apr 2023 07:02:32 [157] For example, Anchiornis huxleyi is currently the smallest non-avialan dinosaur described from an adult specimen, with an estimated weight of 110g (3.9oz)[158] and a total skeletal length of 34 centimeters (1.12ft). A showman named Carl Hagenbeck wrote a book, called Beasts and Men, declaring that dinosaurs might still be alive in Africa. [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. Of these, skin coverings based on keratin proteins are most easily preserved because of their cross-linked, hydrophobic molecular structure. Dinosaur eggs were usually laid in a nest. The largest ornithischian dinosaur was probably the hadrosaurid Shantungosaurus giganteus which measured 16.6 meters (54ft).
Kristin Thompson Lawyer, 1602 Kittyhawk Dr, Columbia, Mo, Articles D