Researchers found two different sites containing 50 dinosaur footprints; stegosaur footprints were distinctly identified among them due to their characteristic oval shape.
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In addition to the stegosaur footprints, they also spied what looked like tracks belonging to large ornithopods, which are like duck-billed dinosaurs.
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"Most stegosaurs we know of, including the Natural History Museum's Sophie, the most complete stegosaur discovered, have been found in Laurasian rock formations," Maidment said.
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The tracks represent some of the oldest evidence anywhere of a stegosaur, according to University of Edinburgh doctoral student Paige dePolo, lead author of the study published in the journal PLOS ONE.
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Fossil remains indicate that stegosaurs have five digits on the forefeet and three weight-bearing digits on the hind feet. From this, scientists were able to successfully predict the appearance of stegosaur tracks in 1990, six years in advance of the first actual discovery of Morrison stegosaur tracks. Since the erection of Stegopodus, more trackways have been found, however none have preserved traces of the front feet, and stegosaur traces remain rare.
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Fossil remains indicate that stegosaurs have five digits on the forefeet and three weight-bearing digits on the hind feet. From this, paleontologists were able to successfully predict the appearance of stegosaur tracks in 1990, six years in advance of the first actual discovery of Morrison stegosaur tracks. Since the erection of Stegopodus, more trackways have been found, however none have preserved traces of the front feet, and stegosaur traces remain rare.
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Mongolostegus was first reported by Alifanov et al. (2005) and Alifanov (2012) as an indeterminate stegosaur based on posterior dorsal and anterior caudal vertebrae as well as pelvic material.Alifanov, B.P., Tumanova, T.A. & Kurzanov, C.M. (2005): [First discovery of a stegosaur in Mongolia]. – Priroda, 12: 61-63.
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Gigantspinosaurus (meaning "giant-spined lizard") is a genus of herbivorous ornithischian dinosaur from the Late Jurassic. It was a stegosaur found in China.
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The type species, W. homheni, is known from the Tugulu Group, while W. ordosensis was found in the Ejinhoro Formation. The approximate age of Wuerhosaurus is 130 mya, based on the approximate dating of the Tsaganstabian fauna, and thus the stegosaur would have lived in the Hauterivian era, which is roughly coeval with the Wealden group, from which other stegosaur material has been found.
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Stegosaur tracks were first recognized in 1996 from a hindprint-only trackway discovered at the Clevland-Lloyd quarry, which is located near Price, Utah."Walk and Don't Look Back: The Footprints; Stegosaurs" Foster (2007) pg. 238 Two years later, a new ichnogenus called Stegopodus was erected for another set of stegosaur tracks which were found near Arches National Park, also in Utah. Unlike the first, this trackway preserved traces of the forefeet.
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Dinosaurs contemporaneous with Xiyunykus in the Tugulu Group of Xinjiang include the stegosaur Wuerhosaurus, the coeval alvarezsaur Tugulusaurus, the carcharodontosaurid Kelmayisaurus, the dubious maniraptoran Phaedrolosaurus, the problematic coelurosaur Xinjiangovenator, and the ceratopsian Psittacosaurus xinjiangensis.
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Lexovisaurus is a genus of stegosaur from mid-to-Late Jurassic Europe, 164.7 mya. Fossils of limb bones and armor fragments have been found in middle to late Jurassic-aged strata of England and France.
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Lower jaw A study by Maidment indicated that Gigantspinosaurus is the most basal known member of the Stegosauria. Peng and colleagues, however, placed it in the Huayangosaurinae. A 2018 redescription by Hao et al clarified aspects of the anatomy and found that it was an intermediate basal stegosaur, sharing basal traits with huayangosaurines as well as somewhat more advanced traits with other stegosaurs. Nevertheless, this analysis found that it was not the most basal stegosaur, as the huayangosaurids Chungkingosaurus and Huayangosaurus were considered more basal.
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Skeletal mount of Stegosaurus. This timeline of stegosaur research is a chronological listing of events in the history of paleontology focused on the stegosaurs, the iconic plate-backed, spike-tailed herbivorous eurypod dinosaurs that predominated during the Jurassic period. The first scientifically documented stegosaur remains were recovered from Early Cretaceous strata in England during the mid-19th century. However, they would not be recognized as a distinct group of dinosaurs until Othniel Charles Marsh described the new genus and species Stegosaurus armatus in 1877, which he regarded as the founding member of the Stegosauria.
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S. weiyuanensis would have lived near a coastal environment and lived alongside the sauropod Sanpasaurus yaoi and an undescribed stegosaur genus. The holotype, IVPP V140, consists of three vertebrae and a tooth, discovered in a layer of the Ziliujing Formation.
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Dinosaur tracksite of the Chacarilla Formation Fossil stegosaur, sauropod and theropod tracks and fossil flora have been reported from the formation.Weishampel et al., 2004, pp.517-607 The fourteen trackways of the Chacarilla III tracksite consist of 76 individual footprints.
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"Table 13.1," in Weishampel, et al. (2004). Page 270 A partial skull and teeth of a stegosaur, Paranthodon, has also been discovered."Table 16.1," in Weishampel, et al. (2004). Page 345 Mesozoic-aged amber has also been recovered from the Kirkwood.
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Maidment has published more than 30 scientific papers, primarily focused on the systematics, evolution and palaeobiology of ornithischian dinosaurs. She has worked extensively on stegosaurs, and is considered the world leader on this group. Her contributions have included overall revisions of the systematics of the group, the description of the Portuguese stegosaur Miragaia, the description of the oldest known stegosaur, Adratiklit, from the Middle Jurassic of Morocco, anatomical and systematic revisions of Chinese stegosaurs, and work on the postcranial skeleton and body mass of Stegosaurus. She has also published several papers on locomotion and the evolution of quadrupedality in ornithischian dinosaurs.
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It has been suggested that stegosaur plates functioned in control of body temperature (thermoregulation) and/or were used as a display to identify members of a species, as well as to attract mates and intimidate rivals. Well known stegosaurs are Stegosaurus and Kentrosaurus.
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Kenneth Carpenter of the Denver Museum of Nature and Science published a preliminary phyletic treeCarpenter, K., Miles, C.A., and Cloward, K. (2001). "New Primitive Stegosaur from the Morrison Formation, Wyoming", in Carpenter, Kenneth(ed) The Armored Dinosaurs. Indiana University Press. , 55–75.
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Yangchuanosaurus is a large theropod from the Shangshaximiao, and it probably preyed on sauropods. The smaller Xuanhanosaurus was also present. In the Xiashaximiao, another theropod, Gasosaurus, was also present, as was the herbivorous stegosaur Huayangosaurus. The latter probably did not compete with sauropods for food.
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Ornithischians were more diverse than they were in the Jurassic Period. Tenontosaurus, Dakotadon, Protohadros, and Eolambia are some of the ornithopods that lived during this time period. Ankylosaurs replaced their stegosaur cousins in the Cretaceous. Ankylosaurs from the Early Cretaceous of North America include Sauropelta and Gastonia.
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Nevertheless, the existence of fragmentary remains and trackways in the deposits of Gondwana indicates the presence of eurypodan taxa there. Adratiklit is the first described eurypodan taxon from North Africa and the oldest known stegosaur from anywhere in the world, with the possible exception of Isaberrysaura.
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This debate is still ongoing; at this time, Scelidosaurus is considered to be either more closely related to ankylosaurids than to stegosaurids and, by extension, a true ankylosaur,Kazlev, M. Alan (2007). "Ornithischia: Ankylosauromorpha" Palaeos. Retrieved on 2007-02-11. or basal to the ankylosaur-stegosaur split.
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A spin-off series of Astrosaurs started on 1 May 2008. This series focuses on Teggs Stegosaur in Astrosaurs Academy, it is based before Teggs becomes an Astrosaur. In Astrosaurs Academy, Teggs has two best friends, Blink and Dutch. Gipsy, Arx and Iggy do not appear in this series.
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Emausaurus has been put on an outgroup to Ankylosauria, with Scelidosaurus and the basal stegosaur Huayangosaurus.Hill RV, Witmer LM, Norell MA. 2003. A new specimen of Pinacosaurus grangeri (Dinosauria: Ornithischia) from the Late Cretaceous of Mongolia: ontogeny and phylogeny of ankylosaurs. American Museum Novitates 3395: 1–29 7\.
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Stegosaurs are easily recognised by the prominent row of plates above the spine and long spines on the tail. Most stegosaurs, but not Stegosaurus, also have a spine over each shoulder. These spines and plates have evolved from the earlier surface scutes. Huayangosaurus is the oldest and most primitive known stegosaur.
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Maidment, S.C., Wei G.-B. & Norman, D.B., 2006, "Re-description of the postcranial skeleton of the Middle Jurassic stegosaur Huayangosaurus taibaii", Journal of Vertebrate Paleontology, 26: 944-956 Mounted skeletons of Huayangosaurus are on display at the Zigong Dinosaur Museum in Zigong and the Municipal Museum of Chongqing in Sichuan Province in China.
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Stegopodus was a new ichnogenus erected in 1998 for the second set of stegosaur tracks from the Morrison Formation. The tracks were found near Arches National Park, also in Utah."Walk and Don't Look Back: The Footprints; Stegosaurs" Foster (2007) pg. 238 Unlike the first, this trackway preserved traces of the forefeet.
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Galton, P.M., 1990, "Stegosauria", in: D.B. Weishampel, P. Dodson, & H. Osmólska (eds.), The Dinosauria. University of California Press, pp. 435-455 Susannah Maidment in 2008 even listed Chialingosaurus kuani among the invalid stegosaur taxa in her phylogeny of Stegosauria.Susannah C. R. Maidment, David B. Norman, Paul M. Barrett and Paul Upchurch (2008).
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The exhibits include the skeletons of the Omeisaurus Zigongensis dinosaur and the Tuojiang stegosaur. The museum also publishes books on dinosaurs. The original museum building was in the Beibei District. A new museum building in the Yuzhong District was under construction as of 2013, consisting of six exhibition halls and covering an area of 14.4 hectares.
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"Amargastegos" is an informally named genus of extinct stegosaurid ornithischian dinosaur known from the La Amarga Formation of Argentina on the basis of MACN N-43 (some dorsal osteoderms, the cervical and caudal vertebrae, and one skull bone). In 2016, Peter Malcolm Galton and Kenneth Carpenter declared it a nomen dubium, establishing it as an indeterminate stegosaur.
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Stegosaurus stenops had four dermal spikes, each about long. Discoveries of articulated stegosaur armor show that, at least in some species, these spikes protruded horizontally from the tail, not vertically as is often depicted. Initially, Marsh described S. armatus as having eight spikes in its tail, unlike S. stenops. However, recent research re-examined this and concluded this species also had four.
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Cambridge, Cambridge University Press, 1999; p. 95. (At the time in question, c. 116–117 Ma, India was located in the southern Indian Ocean; plate tectonics had not yet moved the Indian landmass into its present position.) Note that the stegosaur group of dinosaurs went extinct around this time. Wuerhosaurus, probably the last of the stegosaurs, lived during this time.
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Zoological Journal of the Linnean Society 136(1): 145–169 Shunosaurus accounts for 90% of the fossils found in the Dashanpu fauna, showing it was a dominant and/ or common member of its habitat and environment. It shared the local Middle Jurassic landscape with other sauropods, Datousaurus, Omeisaurus and Protognathosaurus, the possible ornithopod Xiaosaurus, and the early stegosaur Huayangosaurus, as well as the carnivorous theropod Gasosaurus.
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In 2001, it represented the oldest known American stegosaur. It consists of a nearly complete skull and much of the skeleton. It includes the disarticulated elements of the skull, the rear lower jaws, a hyoid, thirteen neck vertebrae, thirteen back vertebrae, three sacrals, forty-four tail vertebrae, neck ribs, dorsal ribs, chevrons, a left shoulderblade, a complete pelvis, ossified tendons and ten neck and back plates.
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During the twentieth century, it has been classified at different times as an ankylosaur or stegosaur. Alfred von Zittel (1902), William Elgin Swinton (1934), and Robert Appleby et al. (1967) identified the genus as a stegosaurian,Thulborn, R.A. (1977) Relationships of the lower Jurassic dinosaur Scelidosaurus harrisonii. Journal of Paleontology. July 1977; v. 51; no. 4; p. 725-739 though this concept then encompassed all armoured forms.
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Astrosaurs is a series of children's science fiction novels written by Steve Cole, which have been released since 2005. The main characters are space-going dinosaurs named Teggs Stegosaur (a Stegosaurus), Gipsy Saurine (a Corythosaurus), Arx Orano (a Triceratops) and Iggy Tooth (an Iguanodon). The series are published by Random House. The first two Astrosaurs books were released on 1 February 2005, with over twenty books following.
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Alshev and Pterobone :One of the Watcher's allies that willingly wants Resentment to be unleashed. He has a massive ego and fancies himself as a genius and an inventor (e.g. making a toothpaste sandwich for people to eat and clean their teeth at the same time). Pterobone is a living fossil that seems to combine aspects of a triceratops, a pterosaur, and a stegosaur.
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Datousaurus, meaning "Big-head Lizard" (from the Chinese da tou "Big Head" and Greek sauros/σαυρος "lizard") was a dinosaur from the Middle Jurassic. It was a sauropod collected from the Lower Shaximiao Formation in Dashanpu, Zigong Sichuan province, China. It shared the local Middle Jurassic landscape with other sauropods such as Shunosaurus, Omeisaurus, Protognathosaurus, the ornithopod Xiaosaurus, the early stegosaur Huayangosaurus as well as the carnivorous Gasosaurus.
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In 1994 however, Zhu Songlin fully described the animal.Zhu Songlin, 1994, "记四川盆地营山县一剑龙化石 [Record of a fossil stegosaur from Yingshan in the Sichuan Basin]", Sichuan Cultural Relics, 1994(S1): 8-14 This fact escaped most Western researchers who considered the taxon invalid until well into the twenty-first century. The generic name is derived from the county of Yingshan.
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The Qigu Formation is a Late Jurassic (Oxfordian) geologic formation in the Southern Junggar Basin in China. Indeterminate Dinosaur remains are among the fossils that have been recovered from the formation, including theropod teeth and a fibula. a stegosaur dorsal vertebra and a Eusauropod tooth. Xinjiangtitan was erroneously thought to be from this formation, but it is actually from the older Qiketai Formation, which is in a different basin.
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In 1985, fossil hunter Patrick McSherry, at the ranch of S.B. Smith in Johnson County, Wyoming, found the remains of a stegosaur. As he had difficulty securing the specimen due to the hard rock matrix, he sought help from Ronald G. Mjos and Jeff Parker of Western Paleontological Laboratories, Inc. They, in turn, cooperated with paleontologist Dee Hall of Brigham Young University. At first, it was assumed it represented an exemplar of Stegosaurus.
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Soon after its description, a controversy arose over the stegosaur's name, which is very similar to the ceratopsian Centrosaurus. Under the rules of biological nomenclature, forbidding homonymy, two animals may not be given the same name. Hennig renamed his stegosaur Kentrurosaurus, "pointed-tail saurian", in 1916, while Hungarian paleontologist Franz Nopcsa renamed the genus Doryphorosaurus, "lance-bearing saurian", the same year. If a renaming had been necessary, Hennig's would have had priority.
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In 1930, American paleontologist Oliver Perry Hay placed Poposaurus in Anchisauridae, a family of sauropodomorph dinosaurs. German paleontologist Friedrich von Huene considered it a very early stegosaur in 1950. In 1961, American paleontologist Edwin Harris Colbert gave an extensive description of the known material of Poposaurus and classified it as a theropod dinosaur. Colbert thought that Poposaurus could not have been a more primitive archosaur because it had hollow leg bones and complex vertebrae.
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The deposit is younger than the Psittacosaurus-bearing Guyang Group, but is still Early Cretaceous. It was found alongside the plates and scapula of a stegosaur. The foot of "Nurosaurus" is notable for a stress fracture present on the first of the fourth digit of the left foot, which was the first identified fracture of its kind, and have since been identified on the phalanges and metatarsals of Apatosaurus, Barosaurus, Brachiosaurus, Camarasaurus, and Diplodocus.
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For example, cranial material is known from Stegosaurus, Paranthodon, Kentrosaurus, and Tuojiangosaurus, and the tooth morphology differs in all of them. Maxilla and premaxilla in multiple views The premaxilla of Paranthodon is incomplete, but the anterior process is sinuous and curves ventrally. This is similar to in Miragaia, Huayangosaurus, the ankylosaur Silvisaurus, and Heterodontosaurus, but unlike in Chungkingosaurus, Stegosaurus, Edmontonia and Lesothosaurus. The premaxilla also lacks any teeth, like in every stegosaur except Huayangosaurus where the premaxilla is preserved.
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The Mugher locality is approximately 151 million years old, about 14 million older than has previously been suggested for Paranthodon, as well as across both southern and eastern Africa. The fauna in the Mugher locality differ from elsewhere of the same time and place in Africa. While the Tendaguru has abundant stegosaurs, sauropods, ornithopods and theropods, the Mugher Mudstone preserves the stegosaur Paranthodon, a hypsilophodontid ornithopod, a probable sauropod, and theropods related to Allosauridae and Dromaeosauridae.
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He assumed that the plates formed a flat skin cover — hence the name, meaning "roof saurian" — and that the animal was bipedal with the spikes sticking out sideways from the rear of the skull. A succession of additional discoveries from the Como Bluff sites allowed a quick update of the presumed build. In 1882, Marsh was able to publish the first skeletal reconstruction of a stegosaur. Hereby, stegosaurians became much better known to the general public.
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Lectotype, partial individual from excavation 'St' at Kindope, Tendaguru, Tanzania Typically for a stegosaur, Kentrosaurus had extensive osteoderm (bony structures in the skin) covering, including small plates (probably located on the neck and anterior trunk), and spikes of various shapes. The spikes of Kentrosaurus are very elongated, with one specimen having a bone core length of 731 millimetres. The plates have a thickened section in the middle, as if they were modified spines. The spikes and plates were likely covered by horn.
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Kentrosaurus was by Hennig assigned to the Stegosauridae in 1915. This is confirmed by modern cladistic analyses, although in 1915 Stegosauridae was a far more inclusive concept. A consecutive narrowing down of this concept caused Kentrosaurus, until the 1980s to be seen as a typical "primitive" stegosaurian, to be placed in a more derived, higher, position in the stegosaur evolutionary tree. Derived traits include a sacral yoke, a long prepubic process, a long thighbone and two rows of plates or spikes.
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This hypothesis was put forth in a broader context of scientists considering the possibility that dinosaurs may have maintained body temperatures and activity levels similar to those of modern birds and mammals, in which case the plates may have served primarily to shed heat rather than gain it. In the late 1980s Buffrenil and others revived the idea that stegosaur plates were display structures, an interpretation that would continue to find favor from researchers like Main and colleagues into the 21st century.
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"Review of the Late Cretaceous nodosauroid Dinosauria: Denversaurus schlessmani, a new armor- plated dinosaur from the Latest Cretaceous of South Dakota, the last survivor of the nodosaurians, with comments on Stegosaur-Nodosaur relationships". Hunteria 1(3): 1-23.(1988). The fossil the species is based on, the holotype DMNH 468, was discovered in a layer of the late Maastrichtian-age Lance Formation of South Dakota. It consists of a skull, lacking the lower jaws, and a number of osteoderms of the body armour.
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Plate of W. homheni, Paleozoological Museum of China Wuerhosaurus homheni is the type species, described by Dong Zhiming in 1973 from the Tugulu Group in Xinjiang, western China. The generic name is derived from the city of Wuerho. Three separate localities in the Wuerho Valley were discovered to contain material from the new stegosaur: 64043-5, 64043 and 64045. The remains consisted of the holotype, Institute of Vertebrate Paleontology and Paleoanthropology (IVPP) V.4006, a skull-less fragmentary skeleton, and the paratype IVPP V.4007.
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The crocodylomorphs Sunosuchus and Junggarsuchus are known from other localities in the "lower beds". Meanwhile, the sauropods Bellusaurus, Mamenchisaurus sinocanadorum, and Tienshanosaurus are known from the "upper beds", above the level of the tuff at 162.2 Ma, and thus were not contemporaries of Klamelisaurus. Asides from these sauropods, Aorun, and Sinraptor, the Oxfordian portion of the Shishugou Formation preserves a diverse dinosaur fauna that also includes the theropods Haplocheirus, Shishugounykus, Zuolong, Guanlong, and Limusaurus; the ornithopod Gongbusaurus; the stegosaur Jiangjunosaurus; and the marginocephalians Yinlong and Hualianceratops.
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Kentrosaurus was a small stegosaur. It had the typical dinosaurian body bauplan, characterised by a small head, a long neck, short forelimbs and long hindlimbs, and a long, horizontal and muscular tail. Typical stegosaurid traits included the elongation and flatness of the head, the powerful build of the forelimbs, erect and pillar-like hindlimbs and an array of plates and spikes running along both sides of the top mid-line of the animal. Only a single complete tooth was known when Hennig published his monography in 1925.
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Maryanska T., 1977. "Ankylosauridae (Dinosauria) from Mongolia", Palaeontologia Polonica 37:85-151 In 2004, Matthew Lamanna e.a. considered it unlikely that any Ornithischia were present in the Maastrichtian of India.Lamanna, M.C., J.B. Smith, Y.S. Attia, and P. Dodson, 2004, "From dinosaurs to dyrosaurids (Crocodyliformes): removal of the post-Cenomanian (Late Cretaceous) record of Ornithischia from Africa", Journal of Vertebrate Paleontology 24: 764-768 The other Late Cretaceous genus from India originally described as a stegosaur, Dravidosaurus, is also a nomen dubium based on plesiosaurian remains.
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Restoration of Gigantspinosaurus (middle) and other dinosaurs from the Shaximiao Formation Gigantspinosaurus was described by Peng and colleagues as a "medium-sized stegosaur". It was estimated by Gregory S. Paul in 2010 to have been about long and in weight.Paul, G.S., 2010, The Princeton Field Guide to Dinosaurs, Princeton University Press p. 222 Gigantspinosaurus has a distinctive appearance with relatively small dorsal plates and greatly enlarged shoulder spines, spinae parascapulares, twice the length of the shoulder blades on which they rested via large flat bases.
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The generic name refers to Huayang, an old name for Sichuan, but at the same time alludes to the Hua Yang Guo Zhi from the Jin Dynasty, the oldest known gazetteer from China. The specific name honours the great Chinese poet Li Bai whose courtesy name was Taibai.Dong, Z., Tang, Z. and Zhou, S.W. (1982). ["Note on the new Mid- Jurassic stegosaur from Sichuan Basin, China"] (in Chinese). Vertebrata PalAsiatica 20 (1) :83-87 The holotype, IVPP V6728, was recovered from a layer of the lower Shaximiao Formation dating from the Bathonian-Callovian.
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Life restoration Size compared to a human It is unknown if the material representing Bellusaurus is from juvenile specimens. Juvenile characteristics of dinosaurs have been noted by Galton in 1982 of stegosaur growth, whose study would suggest that the group of small Bellusaurus sauropods were juveniles that were subjected to a single catastrophe resulting in the mass death assemblage seen from this discovery. Because of the uncertainty of the specimens age, it could be difficult to place the species into a specific taxonomic assignment due to having unstable morphological characteristics.
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Rebbachisaurids like Zapalasaurus presumably fed at ground-level, while basal Titanosauriforms exploited food sources at higher levels. Other dinosaurs of the La Amarga Formation include the stegosaur Amargastegos; predatory dinosaurs include the small ceratosaur Ligabueino, and the presence of a large tetanuran is indicated by teeth. Other than dinosaurs, the formation is notable for the cladotherian mammal Vincelestes, the only mammal known from the Early Cretaceous of South America. Crocodylomorphs are represented by the trematochampsid Amargasuchus – the holotype of this genus was found in association with the Amargasaurus bones.
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Yang's scientific work was instrumental in the creation of China's Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, which today houses one of the most important collections of fossil vertebrates in the world. He was director of both the IVPP and the Beijing Natural History Museum. He supervised the collection of fossil remains of and research on dinosaurs in China from 1933 until the 1970s. He presided over some of the most important fossil discoveries in history, such as those of the prosauropods, Lufengosaurus and Yunnanosaurus; the ornithopod, Tsintaosaurus; and the gigantic sauropod, Mamenchisaurus; as well as China's first stegosaur, Chialingosaurus.
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In 1910, Richard Swann Lull would agree with this hypothesis. Charles Whitney Gilmore disagreed in 1914 and argued that the only protection a stegosaur could gain from its plates was to appear intimidatingly larger to potential predators. Nearly forty years later, Davitashvili argued that the plates were too fragile to be used for defense and instead used to attract mates and signal the stegosaur's rank in a social hierarchy. In the late 1970s, James O. Farlow and others would propose that the thin, blood vessel-rich plates helped absorb or lose body heat, depending on the animal's own physiological requirements.
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An entirely different suggestion was made by John Ostrom who surmised it might have been a sauropod. The first to state that it was a stegosaurian in the modern sense was George Olshevsky in 1993.Olshevsky, G., and Ford, T.L., 1993, "The origin and evolution of the stegosaurs", Gakken Mook, Dinosaur Frontline, 4: 65-103 This was confirmed by Paul Barrett and Paul Upchurch in 1995 who concluded that it is a stegosaur similar to Huayangosaurus, as the jaws are very similar. As the remains are so limited, many recent researchers have concluded Regnosaurus to be a nomen dubium.
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The stegosaur classification has fallen out of favor, but is seen in older dinosaur books. Cladistic analyses have invariably recovered a basal position for Scelidosaurus, outside of the Eurypoda. The position of Scelidosaurus according to a cladistic study of 2011 is shown by this cladogram:Richard S. Thompson, Jolyon C. Parish, Susannah C. R. Maidment and Paul M. Barrett, 2011, "Phylogeny of the ankylosaurian dinosaurs (Ornithischia: Thyreophora)", Journal of Systematic Palaeontology 10(2): 301–312 Fossil records of thyreophorans more basal than Scelidosaurus are sparse. The more "primitive" Scutellosaurus, also found in Arizona, was an earlier genus which was facultatively bipedal.
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Holotype material includes a mostly complete pelvis and sacrum lacking the ischium, the first caudal vertebrae, two dorsal vertebrae, a scapulocoracoid, humerus and phalanx, as well as two dermal plates. Three posterior caudal vertebrae from the tail and a partial ulna of a second individual form the paratype, and Dong referred a partial ischium from a third locality to Wuerhosaurus. A smaller stegosaur from the Ejinhoro Formation in the Ordos Basin in Inner Mongolia, was found in 1988. When the specimen (IVPP V.6877) was described by Dong in 1993, it was named W. ordosensis, as it was from a similar age and had a similar anatomy.
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The Mother’s Day Quarry (MDQ) is a Late Jurassic (Kimmeridgian) fossil site in the Morrison Formation that is located at the base of the Pryor Mountains in Carbon County, Montana. The site was first discovered by the Museum of the Rockies in 1994 and has produced over 2,500 elements since its discovery. Apart from approximately 12 theropod teeth, stegosaur limb material, and two conchostracans found at the site, these elements almost exclusively belong to specimens of the sauropod dinosaur Diplodocus sp. This deposit of fossils is thought to be the result of an age-segregated herd of these dinosaurs congregating at a limited water source and eventually succumbing to drought conditions.
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Carpenter had originally concluded that Hesperosaurus was a rather basal stegosaur. However, Susannah Maidment and colleagues in 2008 published a more extensive phylogenetic study in which it was recovered as a derived form, closely related to Stegosaurus and Wuerhosaurus. They proposed that Hesperosaurus should be considered a species of Stegosaurus, with Hesperosaurus mjosi becoming Stegosaurus mjosi; at the same time Wuerhosaurus was renamed into a Stegosaurus homheni. Carpenter, considering the problem more of a philosophical than a scientific nature, in 2010 rejected the synonymy of Hesperosaurus with Stegosaurus stating that in his opinion Hesperosaurus was sufficiently different from Stegosaurus to be named a separate genus.
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Herbivorous dinosaurs from the Porto Novo Member include, among others, the sauropods Dinheirosaurus and Zby, as well as the stegosaur Miragaia. During the Late Jurassic, Europe had just been separated from North America by the still narrow Atlantic Ocean, and Portugal, as part of the Iberian Peninsula, was still separated from other parts of Europe. According to Mateus and colleagues, the similarity between the Portuguese and North American theropod faunas indicates the presence of a temporary land bridge, allowing for faunal interchange. Malafaia and colleagues, however, argued for a more complex scenario, as other groups, such as sauropods, turtles, and crocodiles, show clearly different species compositions in Portugal and North America.
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Galton and Carpenter considered Alcovasaurus a member of the Stegosauridae, not more closely related to Kentrosaurus than to Stegosaurus. However, a 2017 phylogeny of stegosaurids by Thomas Raven and Susannah Maidment found that Alcovasaurus lacked the fusion between the trochanters of the femur seen in adult eurypodans (stegosaurians and ankylosaurians), which means that it cannot be confidently placed as a stegosaur. However, this may be due to the fact that the specimen is immature, which is impossible to verify since the holotype has been lost. In 2019, Costa and Mateus re-interpreted A. longispinus in the context of newly recognized specimens of Miragaia found in Portugal.
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A sauropod in MUJA The collection of vertebrates of the Jurassic period is unique. Some of the specimens on display in the museum are an incomplete skeleton of a marine crocodile, a piece of the jaw of a small ichthyosaur, a long specimen of ulna (equivalent to the cubitus bone) of a brachiosaurid, the partial skeleton of a stegosaur, several bones of plesiosaurs, bone remnants of sea turtles (including several shells), and also specimens of several partial fish. Also on display are Jurassic period fossil plants. ;Triassic hall Feathered reconstruction of Velociraptor In the Triassic hall, there are exhibits of dinosaurs as they first appeared in the Triassic period, 251 to 200 million years ago.
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Previously, it had been described as a species of Yandusaurus, Y. multidens (He and Cai, 1983), but was reclassified as a new taxon by Paul M. Barrett, Richard J. Butler and Fabien Knoll in 2005, who diagnosed this anatomically conservative species as follows: "A small ornithischian dinosaur distinguished from all other basal ornithischians by a single autapomorphy, the presence of a marked concavity that extends over the lateral surface of the postorbital." The etymology of the genus name honors Professor He Xin-Lu (from the Chengdu University of Technology) who originally named the specimen as Y. multidens + the Greek sauros (=lizard). Hexinlusaurus was a small, fleet-footed herbivore. Other dinosaurs known from Dashanpu include the sauropod Shunosaurus, the theropod Gasosaurus, and the stegosaur Huayangosaurus.
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Witton also discussed an unpublished Ph.D. thesis by the German palaeontologist Michael Fastnacht, wherein biomechanical calculations predicted that Istiodactylus filter-fed in a manner similar to ducks. Witton found that Fastnacht had reconstructed the skull incorrectly, for example by making the rostrum too broad and the jaws too long, resulting in a misleading similarity to the skull of a duck. Pointing out that the jaws were dissimilar to the broad, flattened, and spatulate bills of ducks, and that the teeth were not suited for filter-feeding, he dismissed the idea of a duck-like lifestyle for Istiodactylus. Restoration of a group feeding on a stegosaur carcass in a shallow riverbed, by Witton, 2012 Witton elaborated in 2012 and 2013 on the idea that Istiodactylus was a scavenger.
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A hypothetical recreation of a group of Istiodactylus feeding on a carcass of a stegosaur Ornithocheiromorphs were originally regarded as piscivorous creatures, feeding mainly on small and mid-sized fish. Some paleontologists even suggested details on how these pterosaurs caught fish, some of which included dipping their beaks close to the water for prey. Hooley for example, found that the beak of the well known Istiodactylus was similar to those of birds such as herons, storks, and skimmers, and suggested that Istiodactylus probably fed on fish, this was mainly based on his 1913 jaw reconstruction of the animal. In 1991, Peter Wellnhofer compared the jaw endings of Istiodactylus with those of a duck, but he then noticed that it wasn't a "duck-billed pterosaur" or anything similar, even though it was popularly called that way.
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A thagomizer on the tail of a Stegosaurus fossil There has been debate about whether the spikes were used simply for display, as posited by Gilmore in 1914, or used as a weapon. Robert Bakker noted that it is likely that the stegosaur tail was much more flexible than those of other ornithischian dinosaurs because it lacked ossified tendons, thus lending credence to the idea of the tail as a weapon. He also observed that Stegosaurus could have maneuvered its rear easily by keeping its large hindlimbs stationary and pushing off with its very powerfully muscled but short forelimbs, allowing it to swivel deftly to deal with attack. In 2010, analysis of a digitized model of Kentrosaurus aethiopicus showed that the tail could bring the thagomizer around to the sides of the dinosaur, possibly striking an attacker beside it.
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The skeleton was partly articulated and, in view of healed fractures, belongs to an old individual. It was obtained by the Japanese Hayashibara Museum of Natural Science at Okayama. Deltopectoral crest of the "Lilly" specimen From 1995 onward at the Howe-Stephens Quarry in Big Horn County, Wyoming, named after the historic location of the Howe Ranch, once explored by Barnum Brown, and the new owner Press Stephens, Swiss palaeontologist Hans Jacob Siber excavated stegosaur specimens. The first was SMA 3074-FV01 (also SMA M04), a partial skeleton dubbed "Moritz" after Max und Moritz as an earlier Galeamopus sauropod skeleton from the site had been nicknamed "Max". In 1996/97, specimen SMA 0018 (also mistakenly referred to as SMA V03) was uncovered, dubbed "Victoria" after the feeling of victory the exploring team felt when they discovered Allosaurus "Big Al Two" after the original "Big Al" had been confiscated as federal property.
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The type species name magniventris is derived from the ('great') and ('belly'), referring to the great width of the animal's body. 1908 skeletal reconstruction of AMNH 5895, with missing parts restored after Stegosaurus The skeletal reconstruction accompanying the 1908 description restored the missing parts in a fashion similar to Stegosaurus, and Brown likened the result to the extinct armored mammal Glyptodon. In contrast to modern depictions, Brown's stegosaur-like reconstruction showed robust forelimbs, a strongly arched back, a pelvis with prongs projecting forwards from the ilium and pubis, as well as a short, drooping tail without a tail club, which was unknown at the time. Brown also reconstructed the armor plates in parallel rows running down the back; this arrangement was purely hypothetical. Brown's reconstruction became highly influential, and restorations of the animal based on his diagram were published as late as the 1980s. In a 1908 review of Brown's Ankylosaurus description, the American paleontologist Samuel Wendell Williston criticised the skeletal reconstruction as being based on too few remains, and claimed that Ankylosaurus was merely a synonym of the genus Stegopelta, which Williston had named in 1905.
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