Illustration: Andrey Atuchin/DMNS 2017Working in this high desert terrain, paleontologists from the Natural History Museum of Utah and the University of Utah managed to pull out a number of bones, including an immaculately preserved complete skull, bony armor (including neck rings and spiked plates), several vertebrae, a forelimb, various hindlimb bones, and nearly complete tail with the iconic ankylosaur club still attached.
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Transplantation of the AER to flank mesoderm between the normal limb buds results in ectopic limbs. If the AER is transplanted closer to the forelimb bud, the ectopic limb develops like a forelimb. If the AER is transplanted closer to the hindlimb bud, the ectopic limb develops like a hindlimb. If the AER is transplanted near the middle, the ectopic limb has both forelimb and hindlimb features.
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In animal models, several genes have been found to cause or be associated with sirenomelia. The srn (siren) gene is observed to cause hindlimb fusion in homozygous mice. Mice with knockouts or mutations in both tsg1 and bmp7 will also have hindlimb fusion.
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Hindlimb withdrawal time is another method. Sorin Barac et al. in a recent paper published in the Journal of Reconstructive Microsurgery monitored the response of test rats to pain stimuli by inducing an acute, external heat stimulus and measuring hindlimb withdrawal times (HLWT).
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The position of FGF10 expression is regulated by Wnt8c in the hindlimb and Wnt2b in the forelimb. The forelimb and the hindlimb are specified by their position along the anterior/posterior axis and possibly by two T-box containing transcription factors: Tbx5 and Tbx4, respectively.
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The material includes cervical, dorsal, sacral and caudal vertebrae, the forelimb girdle, and the partial hindlimb.
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In 2008, Carpenter e.a. referred additional material found in Emery County. This includes previously unknown hindlimb elements.
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The radius, ulna, fibula and tibia (the bones which make up the lower forelimb and lower hindlimb, respectively) are very short and very wide compared to the humerus and femur (which make up the upper forelimb and upper hindlimb). The carpal (wrist) and tarsal (ankle) bones are weakly developed.
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Excavation of the right hindlimb of A. olseni specimen AMNH 6554, in 1923. George Olsen on the right In 1923, the Third Asiatic Expedition of the American Museum of Natural History, led by chief paleontologist Walter W. Granger was hunting for dinosaur fossils in Mongolia. On April 25, assistant paleontologist George Olsen excavated and recovered the holotype AMNH 6554, a nearly complete right hindlimb. This included a virtually complete right hindlimb with some elements from the left pes and two manual unguals.
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As no hindlimb elements are known from Enantiornis, it might include one of the El Brete enantiornithines known only from leg bones, namely Lectavis, Soroavisaurus or Yungavolucris. However, these apparently were all smaller birds. Hindlimb material tentatively assigned to Martinavis and Elbretornis seems somewhat and a lot too small, respectively, to represent Enantiornis.
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PVL 4619, the PVL specimen mentioned by Romer, was a partial skeleton including a complete pelvis and left hindlimb, as well as a partial right hindlimb. PVL 4625 was another skeleton discovered later, which included portions of the left hip, left hindlimb, and vertebral column. Paul Sereno and Arcucci redescribed the known material in 1994 and mentioned that an isolated partial femur of this species was also present at the PVL, although Martin Ezcurra (2016) noted that the provided catalogue number, PVL 5000, actually referred to a notoungulate mammal.
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Juvenile sauropods tend to have proportionally shorter necks and tails, and a more pronounced forelimb-hindlimb disparity than found in adult sauropods.
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Numerous experiments have demonstrated that electrical stimulation (ES) of the lumbosacral enlargement and dorsal root can induce locomotor EMG patterns and even hindlimb stepping in acute and chronic low-spinal animals and humans.Grillner S, Zangger P. 1984. The effect of dorsal root transection on the efferent motor pattern in the cat’s hindlimb during locomotion. Acta Physiologica Scandinavia. 120:393–405.
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Duty factors over 50% are considered a "walk", while those less than 50% are considered a run. Forelimb-hindlimb phase is the temporal relationship between the limb pairs. If the same-side forelimbs and hindlimbs initiate stance phase at the same time, the phase is 0 (or 100%). If the same-side forelimb contacts the ground half of the cycle later than the hindlimb, the phase is 50%.
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Elektorornis is an extinct genus of enantiornithean bird known from a partial hindlimb and a small amount of wing plumage. It contains a single species, Elektorornis chenguangi. The hindlimb and feathers were preserved in a piece of 99 million year old Burmese Amber found in Myanmar. In life, the bird would have been slightly smaller than a sparrow and possibly used its characteristically elongated middle toe to probe for food.
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The holotype, MPC-D 100/203, was found in a layer of the Nemegt Formation (perhaps late Campanian - early Maastrichtian). It consists of a partial skeleton lacking the skull. It contains six back vertebrae, two sacral vertebrae, twenty-one tail vertebrae, five ribs, the left shoulder girdle, the left pubic bone, parts of other pelvic bones, the left hindlimb and the right shinbone. The left hindlimb and the tail were articulated.
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Luke D.Einoder and Alastair M.M. Richardson. (2007). Aspects of the hindlimb morphology of some Australian birds of prey: a comparative and quantitative study.Hobart:The Auk 124(3):773-788.
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The known skeleton includes most of the forelimb, shoulder girdle, pelvis, hindlimb and ribs of the holotype, and one shoulder bone, a radius and some vertebrae of the paratype.
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Edgerton et al, 1999a. Retention of hindlimb stepping ability in adult spinal cats after the cessation of step training. Journal of Neurophysiology. 81:85–94.Edgerton et al, 2002.
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However, it differed from the American form by details in the anterior caudal vertebrae and from Barosaurus and Diplodocus both by its plesiomorphic hindlimb proportions with a short lower leg.
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"Management of hindlimb proximal suspensory desmopathy by neurectomy of the deep branch of the lateral plantar nerve and plantar fasciotomy: 155 horses (2003–2008)." Equine Veterinary Journal 44.3 (2012): 361-367.
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The holotype of Pseudolagosuchus, PVL 4629, included most of a left hindlimb and pelvis as well as a fragmentary ankle, vertebrae, and ribs. Other specimens included PVL 3454 (fragments of the hip and hindlimb), MACN 18954 (vertebrae and portions of the hindlimb and ankle), and PULR 53 (tail vertebrae and bones from the ankle region). A 1996 study on dinosaur origins by Fernando Novas also placed a well-preserved femur and tibia (erroneously labelled UPLR 53) within the genus, and this may also be the case with PVL 3455, an indeterminate partial skeleton with some similarities to Arcucci's original material. Despite not sharing much overlapping material, some paleontologists have proposed that Pseudolagosuchus major represented the same species of animal as Lewisuchus admixtus.
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A gene recently discovered in laboratory house mice, termed "mini-muscle", causes, when mutated, a 50% reduction in hindlimb muscle mass as its primary effect (the phenotypic effect by which it was originally identified). In addition to smaller hindlimb muscle mass, the mutant mice exhibit lower heart rates during physical activity, and a higher endurance. Mini Muscle Mice also exhibit larger kidneys and livers. All of these morphological deviations influence the behavior and metabolism of the mouse.
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The thigh bone is longer than the ilium. According to the authors, the hindlimb proportions of oviraptorids do not essentially change during growth, indicating a more sedentary lifestyle and thus probably herbivory.
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T-box transcription factor Tbx4 is a transcription factor that belongs to T-box gene family that is involved in the regulation of embryonic developmental processes. The transcription factor is encoded by the TBX4 gene located on human chromosome 17. Tbx4 is known mostly for its role in the development of the hindlimb, but it also plays a critical role in the formation of the umbilicus. Tbx4 has been shown to be expressed in the allantois, hindlimb, lung and proctodeum.
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Skeletal reconstrucion of Lagerpeton chanarensis. Known elements in white and unknown in dark gray. Lagerpeton is estimated to have been 70 cm (28 in) in length based on the length of the hindlimb; the most complete hindlimb specimen, from PVL 4619, measures 257.9mm from proximal femur to distal ungual. Body mass has been estimated as no more than , based on the slender cross section of limb bones and estimates between more derived dinosauromorphs, such as Silesaurus, and basal saurischians like Eoraptor.
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Although the holotype is very fragmentary, it exhibits an unusual combination of features that reveal a novel phylogenetic position. The forelimb exhibits a bird-like morphology that includes, among other things, a robust ulna, while the hindlimb appears to have been adapted for a cursorial lifestyle. A "sickle-claw" similar to that of dromaeosaurs is also present. Both a flight-adapted forelimb and a cursorial hindlimb are present in Rahonavis, also from Gondwana, and the describers suggest the two are closely related taxa.
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The results from the five-week mission experiment would have been compared against a variety of Earth-based controls, including vivarium, hindlimb suspension, partial weight suspension, flight habitat effects, and short-radius centrifuge testing.
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The Centralian blue-tongue is of a very robust build, short body and slender tail, and is among the largest 1% of species in the family Scincidae. Both the forelimb and hindlimb have five digits.
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The digit formula for Doleserpeton is 4 digits on the forelimbs and 5 digits on the hindlimb. This digit formula is primitive to all living amphibians with a few exceptions in Caecilian and some outlying amphibious species.
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Though the humerus (upper arm bone) and femur (thigh bone) were roughly equal in length, the entire forelimb would have been longer than the hindlimb, as can be inferred from the elongated forearm and metacarpus of other brachiosaurids. This resulted in an inclined trunk with the shoulder much higher than the hips, and the neck exiting the trunk at a steep angle. The overall build of Brachiosaurus resembles a giraffe more than any other living animal. In contrast, most other sauropods had a shorter forelimb than hindlimb; the forelimb is especially short in contemporaneous diplodocoids.
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Palaeontology 49:1263–1286. Muscle restoration of the acetabular-femoral articulation reveals the diverging pattern of locomotion of Dicynodontoides from the typical sprawling gait of most Permian dicynodonts. The hindlimb would have been retracted by a simple rotation of the femoral head, playing a more significant role in the retraction component of the gait than in most other dicynodonts. This feature, though rare in Permian dicynodonts, becomes increasingly more common in the Triassic forms, and Dicynodontoides represents one of many incremental transitions toward upright hindlimb posture in the dicynodont locomotor pattern.
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Furthermore, the transition between gliding and flapping flight is not well-understood. More recent studies on basal pterosaur hindlimb morphology seem to vindicate a connection to Scleromochlus. Like this archosaur, basal pterosaur lineages have plantigrade hindlimbs that show adaptations for saltation.
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Its name means "Ge Sun's silk bird", a reference to the plumulaceous-like body covering evident in the fossil. The specimen's nickname, "Silky", refers to the striking resemblance of the delicate hindlimb filaments to the modern Silky breed of domestic chicken.
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The reason behind the given name is unknown. Suchus (σοῦχος) on the other hand is old Greek for crocodile, as Hesperosuchus is related to crocodilians. Agilis means agile, or agility, for the hypothesis that Hesperosuchus was a very agile animal, based on its hindlimb structures.
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This PT1X gene encodes a transcription factor expressed in hind limbs. When expressed, it causes the formation of hindlimb structures. Liebenberg Syndrome is a result of one of two different genetic mutations. The first is a deletion upstream of the PITX1 gene on chromosome 5.
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As the two known Blikanasaurus specimens are extremely incomplete, very little is understood of this sauropodomorph taxon. The only information that has been deduced is from the bones of its hindlimb anatomy, which are heavily built. This suggests that Blikanasaurus was thickly set and robust.
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A trend in decreased cardiac mass has also been documented in studies of hindlimb-suspended rats. However, hemodynamics in humans differ from hemodynamics in quadrupeds; thus, the rat is not the most appropriate model in which to examine the effects of microgravity on cardiovascular adaptations.
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Appendicular forelimb skeleton The appendicular skeleton contains the fore and hindlimbs. The hindlimb attaches to the vertebral column via the pelvis, while the forelimb does not directly attach to the spine (as a horse does not have a collar bone), and is instead suspended in place by muscles and tendons. This allows great mobility in the front limb, and is partially responsible for the horse's ability to fold his legs up when jumping. Although the hindlimb supports only about 40% of the weight of the animal, it creates most of the forward movement of the horse, and is stabilized through attachments to the spine.
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In the case of the barrel field, the map is somatotopic - based on the arrangement of body parts. Areas corresponding to the nose and mouth are more rostral and lateral in the map, the forelimb, hindlimb and trunk are more medial, with the forelimb rostral of the hindlimb, and the whisker barrel subfields - the posteromedial barrel subfield, which corresponds to the major facial whiskers (the mystacial vibrissae), and the anteriolateral barrel subfield, which corresponds to the smaller whiskers of the face - are caudal and lateral. Although the whiskers make up a relatively small portion of the animal, they dominate the somatotopic map.Hoover et al.
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The lateral plate mesodermal cells secrete fibroblast growth factors (FGF7 and FGF10) to induce the overlying ectoderm to form an organizer at the end of the limb bud, called the apical ectodermal ridge (AER), which guides further development and controls cell death. The AER secretes further growth factors FGF8 and FGF4 which maintain the FGF10 signal and induce proliferation in the mesoderm. The position of FGF10 expression is regulated by two Wnt signaling pathways: Wnt8c in the hindlimb and Wnt2b in the forelimb. The forelimb and the hindlimb are specified by their position along the anterior/posterior axis and possibly by two transcription factors: Tbx5 and Tbx4, respectively.
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By the time Tinirau appeared, many stem tetrapods had already developed the three major hindlimb bones of tetrapods: the femur, tibia, and fibula. While derived stem tetrapods like Panderichthys had hindlimb configurations very similar to the first land-living tetrapods, some early forms such as Eusthenopteron possessed a prominent postaxial process of the fibula hanging over the fibulare bone below it. Tinirau is the earliest known stem tetrapod to have a significantly reduced postaxial process, and a fibula more like those of later tetrapods. Like those of the Late Devonian Panderichthys and Ichthyostega, the glenoid of Tinirau is elongated along the anteroposterior (forward-backward) axis of the body.
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Contrary to its elongated forelimbs, Nyctosaurus had proportionally short hindlimbs compared to the overall body size. Analyses show that Nyctosaurus had the shortest hindlimbs of any pterosaur genera, in terms of hindlimb-to-body ratio, which was only about 16 percent the size of its wing.
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This species can be distinguished by its enlarged femoral scales and its absence of femoral pores; 8-10 lower labials, 10–13 upper labials, 2 internasal scales; 18-22 subdigital lamellaes on its fourth toe of its hindlimb; and about 25-28 scale rows around its midbody.
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"The distal hindlimb musculature of the cat: multiaxis moment arms at the ankle joint". Exp Brain Res (1993) 96:141–151. and has been primarily seen in cats, though it is speculated that such mechanisms may also exist in humans. Results obtained from Young et al.
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Philovenator is known from a single left hindlimb, first discovered in 1988 by the China-Canada Dinosaur Project. The specimen was catalogued as IVPP V 10597. It was found in the Wulansuhai Formation, of China. In 1993, it was described, and assigned as a juvenile of Saurornithoides.
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Evolution of hindlimb posture in non- mammalian therapsids: biomechanical tests of paleontological hypotheses. 27(1): 14-38. Thrinaxodon is prevalent in the fossil record in part because it was one of the few carnivores of its time, and was of a larger size than similar cynodont carnivores.
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Carlson: Human Embryology and Developmental Biology, 4th Edition. Copyright 2009 by Mosby. 184-205. Tbx4 is expressed in the hindlimb, whereas Tbx5 is expressed in the forelimb, heart, and dorsal side of the retina. Studies have shown that fibroblast growth factor (FGF) play a key role in limb initiation.
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These slender skinks have small eyes with no eyelids and no external ear openings. The hindlimb rudiments are visible on either side of cloaca. The body coloration varies from light buff to sulphur yellow. Vague stripes, formed by the scales, can occur along the back and upper flanks.
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Frogs can easily adapt at the surroundings using hindlimbs. The main reason is it can jump high to easily escape to its predator and also to catch preys. It can perform some tricks using the hindlimbs. Frogs have 4 digits in fore limb while hindlimb have 5 digits.
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Most notable of this specialization is the hindlimb morphology. The pelvic girdle consists of a small pubis and an ilium with anteriorly extensive but posteriorly rudimentary processes. The femoral head is offset from the bone, forming an s-shape, and the attachments for the ilio-femoralis muscles are significant.
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It is related to Goggia essexi from which it can be distinguished mainly by the dorsal and ventral scaling and the colour markings. Dimensions: Body length about 30 mm, tail length 30 mm, head length 6 to 7 mm, head breadth 5.2 mm, forelimb 9 mm, hindlimb 12 mm.
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The pelvis is incomplete, with the ilium clearly showing growth lines. The ischium has a thick round dorsal margin and a curved blade. The femur is missing, but the remainder of the hindlimb is present. The tibia is fairly long but quite thin, with a compressed oval cross-section.
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Relative to the hindlimb length, the pelvic girdle is remarkably small. The distance from the pelvic girdle to the femur is therefore also small, more so than most other archosaurs apart from closely related taxa. This reduction in distance may increase the force production during hip extension in extant small mammals.
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The holotype of Aeolosaurus rionegrinus consists of a series of seven tail vertebrae, as well as parts of both forelimbs and the right hindlimb. It was discovered in the Angostura Colorada Formation in Argentina, which dates from the Campanian stage of the Late Cretaceous, about 83 to 74 million years ago.
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Mantellisaurus is known from several localities in Spain. With an articulated hindlimb known from Las Hoyas A specimen is known from the Rubielos de Mora 1 locality in Spain. Three specimens are known from the Arcillas de Morella Formation.J. M. Gasulla, F. Ortega, F. Escaso and A. Pérez-García. 2011.
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This can be explained partly by the finding that moment arms of muscles at the knee and ankle joint in the cheetah are proportionally larger than those of the greyhound.Hudson, P. E., S. A. Corr, et al. (2011). "Functional anatomy of the cheetah (Acinonyx jubatus) hindlimb." Journal of Anatomy 218(4): 363-374.
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Panphagia is currently known from holotype PVSJ 874, the disarticulated remains of one partially grown individual of about long. Portions of the skull, vertebrae, pectoral girdle, pelvic girdle, and hindlimb bones have been recovered. The russet-colored fossils were embedded in a greenish sandstone matrix and took several years to prepare and describe.
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He claimed that the specimen was a chimera including titanosaurid armor, crocodile teeth and theropod hindlimb material.Chakravarti, D. K., 1935, "Is Lametasaurus indicus an armored dinosaur?", American Journal of Science 30(5): 138-141 In 1964 Alick Walker chose the scutes as the lectotype, thus removing the teeth and the bones from the type material.
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B. heteropa can reach a length of snout-to-vent, and its tail may be more than 1.5 times that long. Its limbs are very small relative to its body length. It has four digits on each forelimb, and two digits on each hindlimb. Its body is covered by rows of large, overlapping, hexagonal scales.
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The third metacarpal was rather short and carried a thin, third, finger. In the pelvis there was a little notch in the front edge of the ilium. The relatively long shaft of the ischium curved downwards. The hindlimb was elongated, largely because of a long lower leg, having 90% of the length of the thighbone.
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Bovine progressive degenerative myeloencephalopathy (BPDME), also known as weaver syndrome, is a genetic disorder of cattle, characterized by hindlimb weakness and ataxia. It has been observed in male and female Brown Swiss cattle. It is known as 'weaver syndrome' because of the animals' 'weaving' gait while walking. BPDME is a genetic autosomal recessive disorder.
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TEAD2 is selectively expressed in a subset of embryonic tissues including the cerebellum, testis, and distal portions of the forelimb and hindlimb buds, as well as the tail bud, but it is essentially absent from adult tissues. TEAD2 has also been shown to be expressed very early during development, i.e. from the 2-cell stage.
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Grooming behaviour of a King cheetah Squirrel scratching its armpit with its hindlimb claws - a process of autogrooming. Autogrooming is any grooming behaviour performed by an animal on its own body. This behaviour typically includes licking, chewing, clawing, and rubbing. This comfort behaviour is typically performed for hygienic purposes as seen in the red squirrel.
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In the hindlimb, the 1st phalanx is shorter and the 2nd phalanx is longer than in the frontlimb. In addition, the 2nd and 3rd phalanx are narrower in the hind limb. The angle created by these three bones in the hindleg is steeper by about 5 degrees, therefore making the pastern angle steeper behind than in front.
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Polymorphodon is named based on a holotype specimen, SMNS 91343. This specimen is a disarticulated collection of bones from a single skeleton. It includes parts of the skull, a partial braincase, palatal fragments, sections of the lower jaws, bones of the hip and hindlimb, tail vertebrae, and potential hand bone fragments. Another specimen, SMNS 91400, consists of skull fragments.
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Their biggest find was a nearly complete skeleton of Uintatherium. Fossils of Unitatherium are relatively common, but the specimen uncovered by Gazin's expedition was exceptionally complete and in high quality preservation. The only parts missing from the skeleton were the neck vertebrae, part of one forelimb, and a hindlimb. The fossil was discovered on a steep hillside slope.
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Comparing Didymictis to Vulpavus, a much smaller and more agile viverravid, noted that Didymictis' limbs, especially the hindlimb, are similar to those in extant carnivornas adapted for speed, and the forelimbs to some extent are specialized to digging. The authors concluded that Didymictis was a relatively specialized terrestrial carnivore capable of hunting with speed or pursuing by digging.
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Charles Andrews elaborated on differences between elasmosaurids and pliosaurids in 1910 and 1913. He characterized elasmosaurids by their long necks and small heads, as well as by their rigid and well-developed scapulae (but atrophied or absent clavicles and interclavicles) for forelimb-driven locomotion. Meanwhile, pliosaurids had short necks but large heads, and used hindlimb-driven locomotion.
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Robertia has blunt claws on the end of each phalanx, with a protuberance on the undersides. On one fossil specimen, the metacarpal and the phalanges of the longest finger are the same length as the radius. The S-shaped femur similarly articulates in a right-angled, sprawling position. All dicynodonts had a parasagittal hindlimb posture, besides Robertia.
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In mice, however, both hindlimbs and forelimbs can develop in the presence of either Tbx4 or Tbx5. In fact, it is the Pitx1 and Pitx2 genes that appears to be necessary for specification of the developing hindlimb, whereas their absence results in forelimb development.Tbx4 and Tbx5 appear to be important specifically for limb outgrowth in mice.
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Males can grow to and females to in snout–vent length; typical size for Australia are in males and in females. The body is elongated and the limbs are long and muscular. The tympanum is distinct and relatively larger in males than in females. A dorso-lateral skin fold runs from behind the eye to the hindlimb.
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In 2007, Gishlick and Gauthier concurred that this specimen was probably a new taxon, and tentatively re-classified it as Sinosauropteryx? sp., though they suggested it may belong in a new genus. Also in 2007, Ji, Ji and colleagues wrote that GMV 2124 is probably a new genus, noting the differences in tail length and hindlimb proportions.
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A. Hardel, Caen, 114 p., 8 pl. which was also inserted next year in volume 6 of the "Mémoires de la Société Linnéenne Normandie". The holotype, which was housed in Musée de la Faculté des Sciences de Caen and destroyed during World War II, included gastralia, phalanges, a left forelimb, caudal vertebrae, chevrons, ribs and a hindlimb.
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"A new stegosaurian dinosaur from Upper Cretaceous sediments of south India." Journal of the Geological Society of India, 20(11): 521-530. In 1991, Sankar Chatterjee visited the site and claimed, without presenting concrete morphological evidence, that Dravidosaurus was based on plesiosaurian pelvic and hindlimb elements, the species being a nomen dubium.Chatterjee, S., and Rudra, D. K. (1996).
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This cow with BSE displays abnormal posturing and weight loss. Signs are not seen immediately in cattle, due to the disease's extremely long incubation period. Some cattle have been observed to have an abnormal gait, changes in behavior, tremors and hyper- responsiveness to certain stimuli. Hindlimb ataxia affects the animal's gait and occurs when muscle control is lost.
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Size comparison The holotype specimen, MP111209-1, is known from a near complete skull, and postcranial elements including a complete hindlimb and various vertebrae. Diagnostic features include a very short mandibular symphysis, reduced number of mandibular teeth (17 to 18 versus 25 to 40 in other pliosaurids),Páramo Fonseca et al., 2018, p.232 slender teeth, among other features.
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Preserved portions of the shoulder girdle indicate that Cabarzia had a thin scapula with a convex front edge. The pelvis included an ilium with a long and low dorsal blade and a pubis with a small tubercule. The forelimb is short and robust relative to the long and slender hindlimb. The humerus in particular is thick, with a large entepicondyle.
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The ilium has a distinctively long, leaf-shaped iliac blade which projects up and back at a 45 degree angle, intermediate between the horizontal iliac blade of lizards, and the vertical iliac blade of sphenodontians. Sophineta and Gephyrosaurus have a similarly shaped intermediate ilium. Recovered hindlimb material generally resembles that of generalized lepidosaurs like Sphenodon, though the femur is somewhat more robust.
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Pakicetid elbows are rigid hinge joints like in running mammals and the forearms are not flattened like in truly aquatic cetaceans. In the pakicetid pelvis, the innominates are large and the ischia are longer than the ilia. The pakicetid tibiae are long with a short tibial crest. Hindlimb features that all more reminiscent of running and jumping animals than swimming animals.
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Zanabazar (meaning "Zanabazar") is a genus of large troodontid dinosaurs from the Late Cretaceous of Mongolia. The genus was originally named by Rinchen Barsbold as the new species Saurornithoides junior. In 2009 it was reclassified as its own genus and species, Zanabazar junior, named after the first spiritual figurehead of Tibetan buddhism, Zanabazar. The holotype includes a skull, vertebrae, and right hindlimb.
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NO was released in tissues only in the presence of both the bumped galactosyl-NONOate and the hole-modified β-galactosidase mutant, giving spatiotemporal control of delivery. Hou et al. found markedly increased therapeutic efficiency of NO delivery via the bump-and-hole engineered system, compared to the unmodified pro-drug, in rat hindlimb ischemia and mouse acute kidney injury models.
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All three are based on fragmentary material, and were regarded as indeterminate in the most recent review. M. browni is based on two cervical, two back, and three caudal vertebrae and miscellaneous hind limb elements. M. harriesi is known from a well-preserved forelimb and parts of a hindlimb. M. schwarzi is known from an incomplete hind limb and sacrum.
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It consists of premaxillary and lateral teeth, incomplete left lacrimal, maxillary process of the left jugal, partial right quadratojugal, jugal process of the right ectopterygoid and the quadrate ramus to the right pterygoid. Although the specimen seems to represent a smaller individual. Its affinity to Alectrosaurus is somewhat unresolved since the specimen lacks hindlimb material, making direct comparisons with Alectrosaurus quite complicated.
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In 2007, Xu et al. assigned Gigantoraptor to the Oviraptoridae, in a basal position. The anatomy of Gigantoraptor includes the diagnostic features of the Oviraptorosaurs. However, it also includes several features found in more derived eumaniraptoran dinosaurs, such as a forelimb/hindlimb ratio of 60%, a lack of expansion of the distal scapula and the lack of a fourth trochanter on the femur.
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A. libanensis was named in 1997 on the basis of a single complete skeleton. Although the type locality is unknown, it is said to "almost certainly" originate from the Sannine Formation. The hindlimb of Aphanizocnemus libanensis Aphanizocnemus is about long, and the tail makes up half of its length. The hands and feet are very large in comparison to the limb bones.
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Palaeontographica Abteilung A 44:154–184. Cox pointed out several features, most notably the hindlimb and girdle morphology, that differentiated this genus from other members of Dicynodon, and erected a new genus, Kingoria.Cox, C. B. 1959. On the anatomy of a new dicynodont genus with evidence of the position of the tympanum. Proceedings of the Zoological Society of London 132:321–367.
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The sacrum consisted of three to ten sacral vertebrae. They too, could be connected via a supraneural plate that, however, would not contact the notarium. The shoulder girdle connected to the notarium The tails of pterosaurs were always rather slender. This means that the caudofemoralis retractor muscle which in most basal Archosauria provides the main propulsive force for the hindlimb, was relatively unimportant.
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Barriére G, Leblond H, Provencher J, Rossignol S. Prominent Role of the Spinal Central Pattern Generator in the Recovery of Locomotion after Partial Spinal Cord Injuries. The Journal of Neuroscience. 2008 Apr 9; 28(15):3976-3987. The hindlimb CPGs underwent plastic changes after injury, and after locomotor treadmill training any asymmetries in gait disappeared and bilateral locomotion was achieved.
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Skeletal anatomy of a harbor seal. 1. Skull. 2. Spine. 3. Tail. 4. Hindlimb. 5. Forelimb. 6. Shoulder. 7. Pelvis. 8. Rib cage. Paul de Vos:Two young seals on a beach The earless seals, phocids or true seals are one of the three main groups of mammals within the seal lineage, Pinnipedia. All true seals are members of the family Phocidae .
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Hip joints and hindlimb postures. Appendages can be used for movement in a lot of ways: the posture, the way the body is supported by the legs, is an important aspect. There are three main waysCharig, A.J. (1972) The evolution of the archosaur pelvis and hind-limb: an explanation in functional terms. In Studies in Vertebrate Evolution (eds K.A. Joysey and T.S. Kemp).
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Gland, Switzerland: IUCN. . The rabbit is a gnawing animal that is distinguished from rodents by its two pairs specialized of upper incisors that are designed for gnawing. Their body size and hindlimb development demonstrates how they need extra grass-cover for evasion from predators. Their speediness and their hind limb development relative to their body size correlate to their necessity for evasion action.
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The ischium has a length of 20.5 millimetres. It is relatively short and wide in side view, forming a flat strap. Its obturator process on the front edge, has a rectangular profile, which is rare among the Coelurosauria: except Anchiornis and Archaeopteryx all other coelurosaurs possess a triangular process. The hindlimb is very long, 3.1 times as long as the torso.
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In some snakes, most notably boas and pythons, there are vestiges of the hindlimbs in the form of a pair of pelvic spurs. These small, claw-like protrusions on each side of the cloaca are the external portion of the vestigial hindlimb skeleton, which includes the remains of an ilium and femur. Snakes are polyphyodonts with teeth that are continuously replaced.
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In mammals the caudofemoralis acts to flex the tail laterally to its corresponding side when the pelvic limb is bearing weight. When the pelvic limb is lifted off the ground, contraction of the caudofemoralis causes the limb to abduct and the shank to extend by extending the hip joint (acetabulofemoral or coxofemoral joint). In other tetrapods contraction of the caudofemoralis retracts the hindlimb.
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It consists of the rear of a skull associated with a series of dentary teeth found in their original position. It is part of the collection of the Lingwu Museum. The paratype, LGP V001b, is a partial skeleton lacking the skull. It contains the rear vertebrae of the back, the sacrum, the pelvis, the first tail vertebra and elements of the right hindlimb.
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Although fragmentary, the pelvic girdle is represented by a partial and flattened illium with the ischium. Hindlimb elements include the right femur and left tibia. The preserved femur is straight and strongly robust, the greater trochanter is fused with the lesser trochanter; it measures long. The tibia however, is more shortened but greatly wide, it has a total length of .
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The limb field is a region specified by expression of certain Hox genes, a subset of homeotic genes, and T-box transcription factors – Tbx5 for forelimb or wing development, and Tbx4 for leg or hindlimb development. Establishment of the forelimb field (but not hindlimb field) requires retinoic acid signaling in the developing trunk of the embryo from which the limb buds emerge. Also, although excess retinoic acid can alter limb patterning by ectopically activating Shh or Meis1/Meis2 expression, genetic studies in mouse that eliminate retinoic acid synthesis have shown that RA is not required for limb patterning. The limb bud remains active throughout much of limb development as it stimulates the creation and positive feedback retention of two signaling regions: the AER and its subsequent creation of the zone of polarizing activity (ZPA) with the mesenchymal cells.
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Charig, A.J. & Newman, B.H.†, 1992, "Scelidosaurus harrisonii Owen, 1861 (Reptilia, Ornithischia): proposed replacement in inappropriate lectotype", Bulletin of Zoological Nomenclature, 49: 280–283 Owen intended to call the dinosaur "hindlimb saurian" but confused the Greek word σκέλος, skelos, "hindlimb", with σκελίς, skelis, "rib of beef".R. Owen, 1861, A monograph of a fossil dinosaur (Scelidosaurus harrisonii, Owen) of the Lower Lias, part I. Monographs on the British fossil Reptilia from the Oolitic Formations 1 pp 14George C. Steyskal, 1970, "On the grammar of names formed with -scelus, -sceles, -scelis, etc.", Proceedings of the Biological Society of Washington 84(2): 7-12 The name was inspired by the strong development of the hind leg. Afterwards Harrison sent a knee joint, a claw (GSM 109561), a juvenile specimen and a skull to Owen, that were described in 1861.
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Acostasaurus (meaning "Acosta's lizard") is an extinct genus of possibly Thalassophonean pliosaurid known from the Barremian of the Paja Formation, Colombia. The type specimen, UNDG R-1000, is known from a near complete skull, and postcranial elements including a complete hindlimb and various vertebrae.Marcela Gómez Pérez; Leslie F. Noè (2017). "Cranial anatomy of a new pliosaurid Acostasaurus pavachoquensis from the Lower Cretaceous of Colombia, South America".
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Skeletal reconstruction showing known remains in white and light gray, and unknown in dark gray. The holotype specimen, ULBRA-PVT280, was discovered in the Buriol ravine in São João do Polêsine, Brazil. These rocks are part of the Santa Maria Formation, which dates to the Carnian epoch. The specimen consists of a single skeleton preserving parts of the skull, vertebrae, left forelimb, and left hindlimb.
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Surveys of handlers indicates that about 1 in 3 dogs incur injuries from agility related activities. The most common types of injuries were (in order) strains, sprains and contusions. Locations most commonly injured were shoulders, back, phalanges (forelimb/hindlimb) and neck. Injuries were most commonly perceived as being caused by interactions with bar jumps (contact), A-frames and dog walk obstacles (contact and/or fall).
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The hip and hindlimb was more complete. The ilium has a slightly convex upper edge, a long postacetabular process (rear blade), and a small but distinct preacetabular process (front blade). A tentatively-identified pubis has an expanded and leaf-shaped lower blade as well as an obturator foramen closer to its connection with the ischium. A bone which may be the ischium is straight and flat.
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Jixiangornis is a genus of primitive euavialans from the Early Cretaceous. Like later avialans, it had no teeth, but it also had a long tail, unlike modern birds. Since teeth were still present in some more advanced short- tailed avialans, Jixiangornis seems to have evolved its toothlessness independently of modern birds. The long forelimb (131% of hindlimb length) indicates at least some aerial ability.
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Two rows of scutes ran along the middle of the back, as in other basal crocodylomorphs. The limbs are more complete on the left side; the left upper arm was long, and left ulna was long, so the forearm was noticeably longer than the upper arm. The hand was small. For the left hindlimb, the thigh bone was long and the shin was long.
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The general proportions of the various bones of the lowland kagu are very similar to those of the kagu. They differ in the greater size of the extinct species in averaging about 15% larger, with no overlap between the hindlimb elements and only rare overlap between those of the wings. The describers postulate that R. orarius and R. jubatus were lowland and highland forms, respectively.
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Phrynosomatid lizards show remarkable morphological diversity, including in the relative muscle fiber type composition in their hindlimb muscles. Ancestor reconstruction based on squared-change parsimony (equivalent to maximum likelihood under Brownian motion character evolution) indicates that horned lizards, one of the three main subclades of the lineage, have undergone a major evolutionary increase in the proportion of fast-oxidative glycolytic fibers in their iliofibularis muscles.
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The highly ossified hindlimb suggested that Saurornithoides and other troodontids were well developed at birth and that they probably required little to no parental care. Several other Saurornithoides species were named, though none of these is today seen as valid. In 1928, baron Franz Nopcsa coined Saurornithoides sauvagei. However, this was the result of a printing error: he had planned to name a Teinurosaurus sauvagei.
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The arm is relatively short, equal to 60% of the hindlimb length. Especially the humerus is short, 42.1 millimetres long, with 60% of thighbone length, compared to a ratio of 100% with Anchiornis. The ulna is longer than the upper arm, a trait which in theropods is generally limited to flying birds. The ulna has a length of 47.2 millimetres and is only lightly bowed.
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The forelimbs had only two clawed fingers, along with an additional splint-like small third metacarpal representing the remnant of a third digit. The pelvis was a large structure. Its upper bone, the ilium, was both very long and high, providing an extensive attachment area for hindlimb muscles. The front pubic bone ended in an enormous pubic boot, longer than the entire shaft of the element.
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Only much later Janensch realised that two skeletons had been present. Skelett SI was represented by a skull, six neck vertebrae and some back vertebrae. Skelett SII was larger but despite its size still a subadult individual. It included skull bones, a series of eleven neck and eleven back vertebrae, ribs, the left scapula, both coracoids, both forelimbs, the pubic bones and the right hindlimb.
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Eight posterior dorsal vertebrae, a sacrum of six vertebrae and a tail of thirty-six vertebrae have been preserved, together with a partial ischium, a forelimb and a hindlimb. The describers considered Nanyangosaurus to be of Albian age because of its primitiveness, but the type horizon is now believed to be Turonian-Campanian in age based on plant and invertebrate fossils.Wang, D. et al., 2013.
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Oxford University Press The lower hind limb is composed mainly of the tibia, the fibia being vestigial and fused to the tibia. The hind limb is rotated through 180°, so when walking knees point ventrally. The entire hindlimb is capable of a wide angle rotation, allowing a complete 360° turn when hanging. The toes of this hind limb have claws that are extremely strong and laterally compressed.
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Skeleton of "Saltillomimus" "Saltillomimus" is an informal name for an ornithomimid theropod from the Late Cretaceous (late Campanian) of the Cerro del Pueblo Formation in Mexico. It is known from a partial tail, most of a hindlimb, and forelimb bones that was given the name "Saltillomimus rapidus" by Martinez in 2010. Named in his thesis, the taxon name is an invalid nomen ex dissertatione.
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The holotype consists of a right hindlimb. It contains the thighbone, the shinbone, the second and fourth metatarsal and the third and fourth phalanx of the fourth toe. LAGs (Lines of arrested growth) indicate that it represents a subadult individual of six or seven years old, nearing its maximum size. Additionally, two premaxillary teeth were referred to the species, specimens NCSM 33393 and NCSM 33276.
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Life restoration of Cetiosauriscus as a eusauropod Cetiosauriscus was originally classified by Huene as a genus in the family Cetiosauridae, within the subfamily Cardiodontidae. The subfamily, including the other taxa Cetiosaurus, Haplocanthosaurus, Dystrophaeus, Elosaurus and Rhoetosaurus, was founded upon the general basal features of elongate cervicals and shortened dorsals—both opisthocoelous, amphicoelous caudals that are rod-shaped distally, paired sternal plates, an ilium lacking the postacetabular process (region of the ilium behind the ischium joint and acetabulum), a very wide pubis, wide distal ischium, significantly shorter forelimb than hindlimb, fibula lacking the middle muscle attachment, and long metacarpals and short metatarsals. This classification was emmended in 1932 when Huene concluded Cetiosauriscus was closer to Haplocanthosaurus than Cetiosaurus in the family, because of forelimb and hindlimb proportions. Conversely, in 1956, Alfred Romer synonymised Cetiosauriscus and Cetiosaurus, a position that has not been followed by subsequent studies on the taxon.
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Expression of Tbx4 is activated by a combined "caudal" Hox code, expressing a specified positional code that includes Pitx1 gene expression. The encoded protein plays a major role in limb development, specifically during limb bud initiation. For instance, in chickens Tbx4 specifies hindlimb status. The activation of Tbx4 and other T-box proteins by Hox genes activates signaling cascades that involve the Wnt signaling pathway and FGF signals in limb buds.
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The foot claws of the Dakotaraptor holotype, showing the flexor tubercles for muscle attachment Overall, the hindlimb is built lightly and with long elements, contrary to the robust, stocky hind limbs of Utahraptor. Dakotaraptor more closely resembles the agile, springy smaller dromaeosaurids and would have been well-suited at running and pursuit predation. The length of the thighbone is . It is relatively shorter and more lightly built than that of Utahraptor.
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Carnotaurus was a highly specialized theropod, as seen especially in characteristics of the skull, the vertebrae and the forelimbs. The pelvis and hindlimbs, on the other hand, remained relatively conservative, resembling those of the more basal Ceratosaurus. Both the pelvis and hindlimb bones were long and slender. The left thigh bone of the individual measures 103 cm in length, but shows an average diameter of only 11 cm.
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Robertia had a sprawling gait. The position and rounding of the dorsal articulation area of the femur allowed for a longer stride compared to earlier sprawling animals. The pectoral girdle muscles had a postural function rather than locomotory function and thus provided less thrust than the muscles of the hindlimb. The flexibility of the vertebrae allowed for extensive side to side movement as Robertia moved, similar to a modern lizard.
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Another series of cervical vertebrae ("Series B") underwent a similar reassignment. A scapula and coracoid overlapping the holotype's limb bones likely belongs to a second Gracilisuchus. There are three ilia, none of which belong to the holotype; one belongs to a specimen of Lagosuchus, another to Tropidosuchus. A right hindlimb and a left femur and tibia have been assigned to Tropidosuchus, and another one has been assigned to Lagosuchus.
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The forelimb was more robust than the hindlimb. It was thought that the coracoid was longer than the scapula or shoulder blade, unlike most advanced pterosaurs, but the type specimen had a poorly-preserved coracoid and the second specimen showed this to not be the case. Zhenyuanopterus had relatively short cervical vertebrae compared to Feilongus. Several of the dorsal vertebrae are fused into a notarium, an indicator of maturity.
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Life reconstruction The holotype, MPUM 6009, was found in a layer of the Calcari di Zorzino Formation dating from the early Norian (upper Alaunian). It consists of a partial skeleton including the skull, compressed on a single plate. It is largely articulated and includes the lower jaws, most of the wings, much of the vertebral column except the tail, and hindlimb elements. Some bones have only been preserved as impressions.
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Zupaysaurus was classified as the earliest known tetanuran theropod due to several features of its skull, dentition, and hindlimb. However, several features typical of more basal theropods were also noted by the original authors. Analyses by Carano (2005), Tykoski (2005), and Ezcurra and Novas (2005) have classified Zupaysaurus as a coelophysoid related to Segisaurus and probably Liliensternus, though more basal than Coelophysis.Carrano, M.T., Hutchinson, J.R., & Sampson, S.D. 2005.
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It has been shown, using CKβ knockout mice models, that a defect in the CKβ activity leads to a decrease in the phosphatidylcholine (PC) content in the hindlimb muscle. This, however, does not affect the phoshoethanolamine (PE) content. The net effect is then that the PC/PE ratio decreases and this leads to impaired membrane integrity in the liver. This compromised membrane potential leads to malfunctioning of the mitochondria.
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It was discovered in 1971 during an uranium and thorium exploration by Kenny F. Larsen and was donated to the Dalhousie University in 2004. It was described but not named in 2008; by then it made its way into the collection of the Royal British Columbia Museum in Victoria. It was named in 2019. The holotype, RBCM P900 includes portions of the pectoral girdles, left forelimb, left hindlimb, and right pes.
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Uniquely, there is no process on the top end at the tip of the ischium, and the bone also has a slender obturator process. The pubis points forwards in Liaoningvenator, but backwards in Mei. Additionally, the hindlimb of Liaoningvenator is twice the length of the torso, while in Mei it is 2.8 times the length of the torso. Unlike Sinovenator, Liaoningvenator has a fourth trochanter on its femur.
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Gracilisuchus as restored by Romer in 1972 Three other specimens, stored at the MCZ, were found by Romer and his team in the same locality as the holotype. They are MCZ 1147, a nearly complete skull with jaws; MCZ 4118, parts of the skull, a well-preserved neck, and other elements; and MCZ 4116, a crushed skull and jaw with material from the rest of the body, some of it pertaining to a smaller specimen. José Bonaparte from the Miguel Lillo Institute (PVL) later collected additional material from the site between 1970 and 1972, including two new specimens: PVL 4597, the "Tucuman specimen", which includes a nearly complete skull and jaws, nearly complete cervical and dorsal vertebrae, partial sacral and caudal vertebrae, the hip girdle, most of the left hindlimb, and part of the hindlimb, which is 20% larger than the holotype; and PVL 4612, a nearly complete skull and jaws. In 1972, Romer described the specimens his team had discovered in the journal Breviora.
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The scapulocoracoid (shoulder blade) was quite large and broad unlike most other avemetatarsalians. On the other hand, the glenoid (shoulder socket) was directed somewhat backwards (rather than sideways), as is the case with other dinosauriforms. The forelimb bones (consisting of a humerus, ulna, and radius) were very slender and shorter than the leg bones, and the forelimb as a whole was about half the size of the hindlimb. No portion of the hand was preserved.
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It shows that small land mammals and crocodile existed and have since become extinct. The earliest moa remains come from the Miocene Saint Bathans Fauna. Known from multiple eggshells and hindlimb elements, these represent at least two species of already fairly large sized species. The boundaries defining the Pliocene are not set at an easily identified worldwide event but rather at regional boundaries between the warmer Miocene and the relatively cooler Pliocene.
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Erketu is also diagnosed by bifurcate anterior cervical neural spines, another unusual trait for a titanosauriform. The preserved cervicals include the atlas, axis and C3 to C9, however, the sixth is missing, giving a total of eight preserved cervical vertebrae. The preserved sternum is rather thickened at some borders and shows a very deep lateral edge, it measures about long. The right hindlimb elements were nicely found in articulation and they resemble those of Gobititan.
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The tail of Aeolosaurus was apparently curved strongly downward, a trait likely shared with other members of Aeolosaurini. This curvature would likely have led to the posterior portion of the tail being very low to the ground, though likely not touching it. The curved base of the tail may have enabled the m. caudofemoralis longus, which extended from the femur to the tail vertebrae, to exert more force while retracting the hindlimb.
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Ankylosaurids were likely very slow-moving animals. In all Ankylosauria, the fibula is more slender than the tibia, suggesting that the tibia carried most of the weight of the animal, while the fibula served as an area of muscular attachment. Hindlimb muscles of Euoplocephalus have been restored and the placement of several muscles inserting on the femur have very short moment arms. Muscles inserting on the tibia and fibula have longer moment arms.
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Later that same year, on October 20, an Early Jurassic prosauropod specimen was discovered in a Manchester quarry belonging to Charles O. Wolcott. Workers noticed the pelvis and hindlimb of the animal after the block hypothesized to preserve the front half of the animal had already been used to build a bridge in South Manchester. Othniel Charles Marsh named the animal Anchisaurus major. Four years later, Yale received the type specimen of the phytosaur Clepsysaurus.
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The holotype specimen, CCG 20020, was discovered in Sichuan, in a layer of the Xiashaximiao Formation dating from the Bathonian-Callovian. The specimen consists of a fragmentary skeleton lacking the skull. The holotype proper contains the intercentrum of the atlas and the third to ninth neck vertebrae. Other elements have been designated as a paratype, including fragmentary remains of the skull, nine teeth, elements of the pectoral girdle, a forelimb, and a hindlimb.
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Comparing with Ceratosaurus itself, resulted in a body length of 730 centimetres, a hip height of 220 centimetres and a skull length of eighty centimetres. The thighbone length would then have been about eighty to eighty- seven centimetres, which indicates a body weight of 1160 to 1524 kilogrammes. Another method consisted in extrapolating from the known length of the forelimb. Applying the usual limb ratio indicated a hindlimb length of 198 centimetres.
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Thus, the functional connectivity between mechanoreceptors and specific interneuronal populations within the spinal cord varies according to the physiological state. Even the efficacy of the monosynaptic input from muscle spindles to the motor neuron changes readily from one part of the step cycle to another, according to whether a subject is running or walking.Lovely RG, Gregor RJ, Roy RR, Edgerton VR.1990. Weight-bearing hindlimb stepping in treadmill-exercised adult spinal cats.
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The first was large, tipped with a sharply curved claw, and would rotate inwards when flexed; Robert Bakker called it the 'twist-thumb'. The second digit was the longest, slightly longer than the third. Both of these digits bore claws, while the clawless fourth and fifth digits were very small and simple in comparison. In the hindlimb, the tibia was 30% longer than the femur, which is generally considered an adaptation for speed.
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Asymmetrical gaits are sometimes termed "leaping gaits", due to the presence of a suspended phase. The key variables for gait are the duty factor and the forelimb-hindlimb phase relationship. Duty factor is simply the percent of the total cycle which a given foot is on the ground. This value will usually be the same for forelimbs and hindlimbs unless the animal is moving with a specially trained gait or is accelerating or decelerating.
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Stratesaurus is known from the holotype specimen OUMNH J.10337, a dorsoventrally crushed but nearly complete skull, and three-dimensionally preserved partial postcranial skeleton including anterior cervical and pectoral vertebrae, a partial hindlimb and ilium. GSM 26035 was referred to S. taylori because it shares one autapomorphy and other characters with the holotype specimen. It consists of a skull and some anterior cervical vertebrae. AGT 11 was also referred to S. taylori.
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This deletion includes the H2AFY gene, which is responsible for suppressing an upstream enhancer element known as hs1473. When H2AFY is removed, the enhancer is brought closer to PITX1 and inappropriately enhances it in forelimbs, causing them to adopt hindlimb morphology. The second mutation that can cause the phenotype for Liebenberg syndrome is a translocation of chromosome 18 and chromosome 5. Translocation mutations are ones that switch parts of non-homologous chromosomes with each other.
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The hindlimb ended in a three-toed foot (pes), with a raised hallux. The tail had an unusual structure within its interlocking prezygapophysis of its vertebrae, which formed a semi- rigid lattice, apparently to stop the tail from moving up and down. C. bauri profile Coelophysis had a long narrow head (approximately ), with large, forward-facing eyes that afforded it stereoscopic vision and as a result excellent depth perception. Rinehart et al.
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The shape of the humerus is similar to the shortness of Neuquensaurus, although overall the forelimb is long, as in Diplodocus and Cetiosaurus, being 69% of the femur length. The distal end is roughened for a large cartilage cap as found in some other eusauropods like "Cetiosauriscus" greppini. The radius and ulna are broken, but complete they would have been long. The hindlimb of Cetiosauriscus is about the length of the forelimb.
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It is very slender, being tall but only wide at the middle. This very gracile femoral morphology is shared with Amphicoelias, Shunosaurus, Ligabuesaurus and a specimen of Diplodocus, being more gracile than Cetiosaurus and most other eusauropods. A prominent fourth trochanter is present, but the remaining shaft is very compressed. The tibia, fibula and pes are also preserved, but are fragmentary and disarticulated making comparisons difficult, the lower hindlimb being about upright.
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The holotype, a thighbone, is part of specimen CCG 20010. Vertebrae, pelvic bones and hindlimb elements, also catalogued under this inventory number, may belong to the same individual. The specimen has unfused neurocentral sutures in its vertebrae, meaning that the animal was immature at the time of death. The formation in which it was discovered was the Lower Shaximiao Formation, meaning Chuandongocoelurus dates to the Bathonian or Callovian stage of the Middle Jurassic.
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Whiskers may have been typical of cynodontia as a whole, or have evolved in this group. Derived cynodonts developed epipubic bones. These served to strengthen the torso and support abdominal and hindlimb musculature, aiding them in the development of an erect gait, but at the expense of prolonged pregnancy, forcing these animals to give birth to highly altricial young as in modern marsupials and monotremes. Only placentals, and perhaps Megazostrodon and Erythrotherium, would lose these.
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This feature is the presence of several large keels which run along the underside of each pleurocentrum. Although keels also run along the underside of the pleurocentra in synapsids, these keels are much closer to the midline in members of that group compared to in Westlothiana. The ribs of Westlothiana connect to the intercentra, and are present in every vertebra between the skull and the hip. The forelimb was significantly shorter than the hindlimb, a characteristic shared with lepospondyls.
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Fragmentary additional remains from Bahariya, including vertebrae and hindlimb bones, were designated by Stromer as "Spinosaurus B" in 1934. Stromer considered them different enough to belong to another species, and this has been borne out. With the advantage of more expeditions and material, it appears that they pertain either to Carcharodontosaurus or to Sigilmassasaurus. S. maroccanus was originally described by Dale Russell in 1996 as a new species based on the length of its neck vertebrae.
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Cryptoclidus was a plesiosaur whose specimens include adult and juvenile skeletons, and remains which have been found in various degrees of preservation in England, Northern France, Russia, and South America. Its name, meaning "hidden clavicles", refer to its small, practically invisible clavicles buried in its front limb girdle. The type species was initially described as Plesiosaurus eurymerus by Phillips (1871). The species name "wide femur" refers to the forelimb, which was mistaken for a hindlimb at the time.
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A structure can be homologous at one level, but only analogous at another. Pterosaur, bird and bat wings are analogous as wings, but homologous as forelimbs because the organ served as a forearm (not a wing) in the last common ancestor of tetrapods, and evolved in different ways in the three groups. Thus, in the pterosaurs, the "wing" involves both the forelimb and the hindlimb. Analogy is called homoplasy in cladistics, and convergent or parallel evolution in evolutionary biology.
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1-4, four contiguous fragments of a first phalanx, together measuring long; IWCMS 2002.233, a possible distal end, long, of a second phalanx; IWCMS 2002.236, a fragment of the shaft of possibly the fourth phalanx; and IWCMS 2003.3, a probable fragment of a hindlimb bone. The fossils have only been slightly compressed. The snout fragments have a combined length of . On the snout top the base of a crest is visible, not quite reaching its rounded tip.
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A moderately developed fourth trochanter is placed proximally on the femur, unlike the well developed fourth trochanters of dinosaurs. The manus and pes are almost entirely missing, except for the calcanues of the ankle joint. The calcaneus indicates that Yarasuchus had a "crocodile-normal" ankle, which allowed for more rotation of the foot than the derived hinge-like avemetatarsalian ankle. The forelimb to hindlimb length ratio is roughly 3:5, with much longer back legs than the front.
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Early genera had long forelimbs, about 60% the length of the hindlimb in Guanlong, with the typical three digits of coelurosaurs. The long forelimb persisted at least through the Early Cretaceous Eotyrannus, but is unknown in Appalachiosaurus. Derived tyrannosaurids have forelimbs strongly reduced in size, the most extreme example being Tarbosaurus from Mongolia, where the humerus was only one-quarter the length of the femur. The third digit of the forelimb was also reduced over time.
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The holotype, MUCPv-208, was uncovered in a layer of the Anacleto Formation, dating from the early Campanian, about 83 million years old. It consists of a partial skeleton with skull, lacking much of the vertebral column. The paratype is MUCPv-212, a tail with lower hindlimb elements. In 1997 three additional specimens were described: MUCPv 213, a partial skeleton with skull; MCSPv 111, a postcranial skeleton; and MCSPv 112, a skull with hindlimbs and pelvis.
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The limbs could not move alternately as they lacked the necessary rotary motion range. In addition, the hind limbs lacked the necessary pelvic musculature for hindlimb-driven land movement. Their most likely method of terrestrial locomotion is that of synchronous "crutching motions", similar to modern mudskippers. (Viewing several videos of mudskipper "walking" shows that they move by pulling themselves forward with both pectoral fins at the same time (left & right pectoral fins move simultaneously, not alternatively).
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Gower and Schoch (2009), p. 109. The toe bones (phalanges) are poorly preserved and the only well known bone is a fifth metatarsal (bone in hindlimbs attached to the toe bones) which was hooked in shape. However, hypotheses suggest that probably each forelimb had four toes and each hindlimb five.Gower and Schoch (2009), p. 119 (Figure 8). Skull, Staatliches Museum für Naturkunde Stuttgart Batrachotomus had a tall and narrow skull estimated at in length.Gower (1999), p. 7.
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The foot is elongate with pointed claws and does not appear to be particularly specialized. The shoulder girdle and forelimbs are more representative of Dicynodontia as a whole than the hindlimbs. The girdle is high and narrow, reflecting a reduction in the backward-forward pulling muscles, which would have been situated above and below the humerus. The humerus suggests an emphasis of long-axis rotation, a much more conservative morphology than that of the hindlimb structure.
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An anhanguerid pelvis seen from above, with the right side rotated towards the viewer The pelvis of pterosaurs was of moderate size compared to the body as a whole. Often the three pelvic bones were fused. The ilium was long and low, its front and rear blades projecting horizontally beyond the edges of the lower pelvic bones. Despite this length, the rod-like form of these processes indicates that the hindlimb muscles attached to them were limited in strength.
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As a cell adhesive substrate, CYR61 induces the activation of focal adhesion kinase, paxillin, RAC, and sustained activation of MAPK/ERK1-2. In macrophages, CYR61 also activates the transcription factor NFκB and stimulates M1 polarization. CYR61 activates Akt signaling in thymic epithelial cells, promoting their proliferation and thus thymic size growth. CYR61 has potent angiogenic activity upon endothelial cells and induces neovascularization, first demonstrated in a corneal micropocket implant assay and subsequently confirmed in a rabbit ischemic hindlimb model.
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Blikanasaurus is a genus of sauropodomorph dinosaur from the late Triassic of South Africa. The generic name Blikanasaurus is derived from Greek, meaning "lizard from Blikana". The species name cromptoni is taken from the surname of A.W. “Fuzz” Crompton, an American paleontologist who led numerous field expeditions in Elliot Formation outcrop localities in South Africa. Blikanasaurus is only known from partial hindlimb bones that were recovered from the lower Elliot Formation (LEF) in the Eastern Cape.
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At stage 14 (620–680 hours post-fertilisation), miRNA-10 is localised to the posterior midgut and the anal pad. In Drosophila larvae, miR-10-3p is found in the imaginal discs (groups of cells which are destined to become adult structures upon metamorphosis). Expression of miR-10ba in mouse embryos shows a similar pattern to that of the Hoxb4 gene. Highest levels are found in the posterior trunk of the embryo, surrounding the hindlimb buds.
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Additional findings comprising forelimb and hindlimb elements have been discovered during the 1960s-1980s. Therizinosaurus comprises the single species T. cheloniformis, which could grow up from long and weigh possibly over . It had the longest known claws of any land animal, reaching up to in length. Unlike other therizinosaurs, the claws were very stiff and elongated, but like other members, it would have been slow, long-necked/high browser herbivore equipped with a keratinous beak and a wide torso.
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To the end of this, necrosis occurs by physical interaction with the PTP regulator cyclophilin D (CypD). The mitochondrial p53-CypD axis as an important contributor to oxidative stress-induced necrosis and implicates in disease pathology and possible treatment. Cyclosporine A, known as a potent the mitochondrial permeability transition pore (mPTP) opening inhibitor and extremely powerful in protecting cardiomyocytes from IR, normalized ROS production, decreased inflammation, and restored mitochondrial coupling during aortic cross-clamping in rat hindlimb IR model.
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Goyocephale is an extinct genus of pachycephalosaurian ornithischian that lived in Mongolia during the Late Cretaceous about 76 million years ago. It was first described in 1982 by Perle, Teresa Maryańska and Osmólska for a disarticulated skeleton with most of a skull, part of the forelimb and hindlimb, some of the pelvic girdle, and some vertebrae. Perle et al. named the remains Goyocephale lattimorei, from the Mongolian goyo, meaning "decorated", and the Ancient Greek kephale, for head.
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The limbs are yellowish white below. The tail is light brown above, but has two rows of darker spots, and yellowish white below.Roux, 1907, pp. 301-302 Snout-to-vent length is 83 mm (3.3 in), head length 10 mm (0.39 in), head width 6.5 mm (0.26 in), length of the body 33 mm (1.3 in), length of the forelimb 15 mm (0.59 in), length of the hindlimb 23 mm (0.91 in), and length of the (incomplete) tail 40 mm (1.6 in).
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Many other studies supported these arguments, sometimes even scoring the two as a single taxon in their phylogenetic analyses. Several hindlimb, hip, and vertebral fossils (PVL 3456, PULR-V 112 and PULR-V 113) have additionally been referred to Lewisuchus based on their similarity to Pseudolagosuchus remains. However, Bittencourt et al.'s 2014 redescription of the Lewisuchus holotype refrained from synonymizing the two due to a lack of data, with the only overlapping material being the tibia and a few cervical (neck) vertebrae.
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Ossified tendon from an Edmontosaurus bone bed in Wyoming (Lance Formation) In some organisms, notable ones being birds and ornithischian dinosaurs, portions of the tendon can become ossified. In this process, osteocytes infiltrate the tendon and lay down bone as they would in sesamoid bone such as the patella. In birds, tendon ossification primarily occurs in the hindlimb, while in ornithischian dinosaurs, ossified axial muscle tendons form a latticework along the neural and haemal spines on the tail, presumably for support.
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Its fibular crest ends in a hook-shaped process pointing to above, a condition that is unique in the entire Theropoda. The astragalus and calcaneum, the upper ankle bones, are fused just as in Bambiraptor. The top of the calcaneum has but a small contact facet for the calfbone, indicating that this fibula must have had a very narrow lower end. The metatarsus has an estimated length of , which makes it rather long relative to the remainder of the hindlimb.
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Kwangsisaurus is known solely from the holotype IVPP V2338, a fragmentary postcranial skeleton housed at the Institute of Vertebrate Paleontology and Paleoanthropology. The skeleton consists of 20 back vertebrae, 5 front-most tail vertebrae, badly persevered pelvic girdle, and the left hindlimb. IVPP V2338 was collected at Fupingtun, Dengilu of Wuming, Guangxi Province, from the Beisi Formation of the Loulou Group. Its dating is uncertain, but falls within the Olenekian or Anisian stage of the late Early Triassic or early Middle Triassic.
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The presence of alula and a complete set of aerodynamic asymmetric feathers arranged forming a modern wing, (2012): "Primitive Wing Feather Arrangement in Archaeopteryx lithographica and Anchiornis huxleyi", Current Biology, . indicate well develop flight capabilities, as in many other enantiornithean taxa. Its hindlimb morphology remain uncertain as no material of this kind referable to the genus has been found to date. A 2018 study analyzed the proportions of Eoalulavis and Concornis to determine the optimal flight pattern for those genera.
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These studies revealed for the first time a functional organization to the central termination pattern of unmyelinated afferents with different response profiles to skin stimulation.Sugiura Y, Lee CL, and Perl, ER. Central projections of identified, unmyelinated (C) afferent fibers innervating mammalian skin. Science 234: 358-361, 1986. Experiments performed by Christopher Honda, Siegfried Mense, and Perl in the early 1980s demonstrated that neurons located in specific areas of the cat thalamus were responsive to noxious stimulation of the skin of the hindlimb.
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The holotype specimen, MPCA 245, consists of a partial skeleton with skull of an adult individual. The paratype is MPCA 238, a sacrum with a right pelvis and right hindlimb. The skull of the holotype was described in detail in 2017, while 2018 saw a slew of new papers on the anatomy of the genus. These include descriptions of new specimens, a study on the tail anatomy of the genus, and a general overview of the postcrania of multiple specimens.
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As with most tetrapods, the shoulder joint was formed by the scapula and coracoid. In the pelvis, the bone plate was formed by the ischium at the rear and the larger pubic bone in front of it. The ilium, which in land vertebrates bears the weight of the hindlimb, had become a small element at the rear, no longer attached to either the pubic bone or the thighbone. The hip joint was formed by the ischium and the pubic bone.
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77 The best- known examples are the American Mustang and the Australian Brumby, but there are many other populations worldwide. See also semi-feral horse (to which the term "feral" is often misapplied). ;fetlock :The joint above the pastern.Belknap Horsewords pp. 183–184 Anatomically, the metacarpophalangeal (front) and metatarsophalangeal (rear) joints of the horse, formed by the junction of the third metacarpal (forelimb) or metatarsal (hindlimb) bones (also known as the cannon bones) and the proximal phalanx distad (the pastern bone).
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Unlike modern macropodids, which hop (either bipedally or quadrupedally), sthenurines seem to have abandoned saltation as a means of locomotion. Their comparatively inflexible spines, robust hindlimb and pelvic elements, and the lack of capacity for rapid hopping suggest that these animals walked bipedally, somewhat like hominids, even converging with those primates in details of their pelvic anatomy. Furthermore, their hooved single digits and metatarsal anatomy suggest that unlike their plantigrade relatives, sthenurines were unguligrade, walking on the tips of their "toes".
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A few specimens indicate a maximum length of 11–30% greater than average and a mass of . The cervical vertebrae of Apatosaurus are less elongated and more heavily constructed than those of Diplodocus, a diplodocid like Apatosaurus, and the bones of the leg are much stockier despite being longer, implying that Apatosaurus was a more robust animal. The tail was held above the ground during normal locomotion. Apatosaurus had a single claw on each forelimb and three on each hindlimb.
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In 1936 Charles Gilmore noted that previous reconstructions of Apatosaurus forelimbs erroneously proposed that the radius and ulna could cross; in life they would have remained parallel. Apatosaurus had a single large claw on each forelimb, a feature shared by all sauropods more derived than Shunosaurus. The first three toes had claws on each hindlimb. The phalangeal formula is 2-1-1-1-1, meaning the innermost finger (phalanx) on the forelimb has two bones and the next has one.
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Most of its postcranial skeleton is known. The skeletal material Jain and Bandyopadhyay found between 1984 and 1986 was "in associated and mostly articulated condition;" it included cervical, dorsal, sacral and caudal vertebrae, ribs, pelvis, scapula, coracoid, left forelimb and other bones, though skull, hindlimb and foot bones were missing. The site locality is Dongargaon Hill, which is in a Maastrichtian crevasse splay claystone in the Lameta Formation of India. Dongargaon Hill (20.212318N,79.090709E) is located near Warora, in Chandrapur District, Maharashtra.
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The specific name refers to strange bone elements found along the vertebrae, for which Molnar coined the designation paravertebrae. The holotype, QM F10329, was discovered in a layer of the Bungil Formation, the Minmi Member, a lagoon deposit which was first dated to the Barremian-Valanginian, but later was recalibrated to the Aptian. It consists of a partial skeleton, lacking the skull. It preserves a series of eleven back vertebrae, ribs, a right hindlimb, and plates of the belly armour.
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This hypothesis may also be supported by the hindlegs of Majungasaurus, which were short and stocky, as opposed to the longer and more slender legs of most other theropods. While Majungasaurus would not have moved as fast as other similar-sized theropods, it would have had no trouble keeping up with slow-moving sauropods. The robust hindlimb bones suggest very powerful legs, and their shorter length would have lowered the animal's center of gravity. Thus Majungasaurus may have sacrificed speed for power.
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Sunnybatrachus is a genus of extinct frog that lived during the Berriasian epoch of the Early Cretaceous of England. The only known material, including the holotype ilium as well as bones of the skull, vertebral column, forelimb, pelvis, and hindlimb was named Sunnybatrachus purbeckensis by Susan E. Evans and Gerard J. McGowan in 2002. The species name describes the Purbeck Limestone Group, while the genus name is for the Sunnydown Farm locality of the Lulworth Formation, where the fossils were found.
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Blikanasaurus was first discovered by a partial hindlimb (epipodium and pes) found in the lower Elliot Formation (LEF) at the foot of Blikana mountain in Herschel, Eastern Cape of South Africa around 1965. In the early 2000s, a second specimen - consisting of only a right metatarsal - was recovered from lower Elliot Formation deposits on the farm, Damplaats, in Ladybrand of the eastern Free State. A possible ilium that has been attributed to Blikanasaurus was found recently, although this remains to be confirmed.
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"A fourth Australian Mesozoic mammal locality". Museum of Northern Arizona, Bulletin 65: 677–681Herne, M. (2013). "Anatomy, systematics and phylogenetic relationships of the Early Cretaceous ornithopod dinosaurs of the Australian-Antarctic rift system" PhD Thesis. The University of Queensland The type specimen, preserving a partial tail and hindlimb The specimens were described and named online, through use of ZooBank registration, in January 2018, in a study in which the sedimentology, taphonomy, palaeoecology, and stratigraphy of the site were also investigated.
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Its consists of five vertebral centra, a neural arch, one dorsal and two sacral ribs, the right ischium, the complete right hindlimb, the right pes, an incomplete left pes, and various other fragments. AMNH 5266 was discovered in 1912 at Red Deer River and was collected by Barnum Brown with assistance from Peter Kaisen, George Olsen, and Charles M Sternberg in the sediments from the Horseshoe Canyon Formation.Coombs, W.P., Jr. (1986, June). A Juvenile ankylosaur referable to the genus euoplocephalus (reptilia, ornithischia).
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Loss of CD47 promotes proliferation and increases asymmetric division of primary murine endothelial cells. Additionally, activation of CD47 with TSP-1 in wild-type primary mouse cerebral endothelial cells induces cytotoxicity, which is significantly decreased in cerebral endothelial cells derived from CD47 knockout mice. CD47 signaling may suppress angiogenesis as TSP-1 activation significantly inhibited endothelial cell migration and tube formation in vitro. In vivo, injections of TSP-1 in mice after hindlimb ischemia induces a significant decrease of blood flow recovery.
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"Orcomimus" (Pronounced or-coh-MEEM-us) is the name given to an as yet undescribed genus of dinosaur from the Late Cretaceous period 66 million years ago. The dinosaur was an ornithomimid which lived in what is now South Dakota, in the United States. The type was coined by Michael Triebold in 1997, but has never been formally described and is currently a nomen nudum. "Orcomimus" was a bipedal theropod, but the dinosaur is known from only a pelvis and a hindlimb.
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On the front of its shaft a large hatchet-shaped obturator process is present, the attachment for the Musculus puboischiofemoralis externus, that lacks a small circular notch between its lower edge and the shaft, though this lack is normally associated with the possession of a lower triangular processus obturatorius. Of the hindlimb, the lower leg is missing. The femur or thigh bone is straight and robust. The lesser trochanter is markedly lower than the greater trochanter and separated from it by a narrow cleft.
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The holotype of Akidolestes cifellii, reserved in the Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, has a complete skeleton with a partial skull and dentition. It displays characteristics of monotremes but appears to be more related to modern therian mammals. Although it had some features similar to monotremes in the lumbar vertebrae, pelvis, and hindlimb, Akidolestes cifellii is still placed in the Spalacotheriidae family and close to Zhangheotherium and Maotherium. Those convergent synapomorphies might derive from a shared early common ancestor.
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Reconstructed skull of IGM 100/1 The holotype was discovered in 1964 from the Bügiin Tsav locality of the Nemegt Formation and initially described by Rinchen Barsbold as a new species of Saurornithoides (S. junior) in 1974. This specimen, IGM 100/1, includes a nearly complete skull and braincase, part of the pelvis, some tail vertebrae, and parts of the right hindlimb. In 2009 a review of the genus found that the support for S. junior in the same genus as S. mongoliensis was lacking.
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During the breeding season, male dancing frogs call from spots close to running water and display their prominent white vocal sacs. Males tap their hindfeet and extend it, subsequently stretching the foot outward and shaking it, both at prospective mates and rival males. This type of hindleg movement has been termed as "foot- flagging" and has been observed in many, but not all, Micrixalus species and evidence inferred for a few other species as well. Foot flagging is done with either hindlimb and also while calling.
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Yueosaurus is known only from the holotype ZMNH M8620, an articulated, partial but well preserved postcranial skeleton which includes cervical, dorsal (back) and caudal vertebrae, scapula, rib, hip bones, partial forelimb and partial hindlimb. It was collected in Tiantai locality from the Liangtoutang Formation, dating to the Albian- Cenomanian stages of the latest Early Cretaceous and the earliest Late Cretaceous. Yueosaurus represents the southernmost basal ornithopod dinosaur from Asia, and the first one from China. It differs from other ornithischians by a combination of characters.
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California mice (Peromyscus californicus) are well known for have intensive and sustained paternal behavior. Several species of rodents have been studied as models of paternal care, including prairie voles (Microtus ochrogaster), Campbell's dwarf hamster, the Mongolian gerbil, and the African striped mouse. The California mouse (Peromyscus californicus) is a monogamous rodent that exhibits extensive and essential paternal care, and hence has been studied as a model organism for this phenomenon. One study of this species found that fathers had larger hindlimb muscles than did non-breeding males.
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Since Patagosaurus is known from many specimens, including at least one juvenile, its anatomy and growth are fairly well understood. Both ages exhibit the typical features of a sauropod, a long neck, small head, a long tail, and being quadrupedal. The juvenile exhibits features different from the adult in regions like the mandible, pectoral girdle, pelvis and hindlimb, although overall their anatomy is quite similar. The many known specimens help fill in gaps in the anatomy of the genus, such as the forelimb and skull.
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The species Plesiosaurus megadeirus was coined for two partial postcranial specimens in a publication cataloging Mesozoic tetrapod specimens in the collections of the Sedgwick Museum of Earth Sciences at the University of Cambridge.H. G. Seeley. 1869. Index to the Fossil Remains of Aves, Ornithosauria, and Reptilia, from the Secondary System of Strata, Arranged in the Woodwardian Museum of the University of Cambridge. Deighton, Bell, and Co, Cambridge 1-143 The name Pliosaurus portlandicus was coined for a partial hindlimb from Dorset,R. Owen. 1869.
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Gwyneddosaurus is a possibly invalid genus of extinct aquatic tanystropheid reptile. The type species, G. erici was described in 1945 by Wilhelm Bock, who identified it as a coelurosaurian dinosaur related to Podokesaurus (at the time, "podokesaurids" were thought to be coelurosaurians). Its remains were found in the Upper Triassic Lockatong Formation of Montgomery County, eastern Pennsylvania, and include skull fragments, several vertebra, ribs, gastralia, partial shoulder and hip bones, and several forelimb and hindlimb elements found in soft shale. The type specimen is ANSP 15072\.
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Skeleton of the lower forelimb A fetlock (a MCPJ or a MTPJ) is formed by the junction of the third metacarpal (in the forelimb) or metatarsal (in the hindlimb) bones, either of which are commonly called the cannon bones, proximad and the proximal phalanx distad, commonly called the pastern bone. Paired proximal sesamoid bones form the joint with the palmar or plantar distal surface of the third metacarpal or metatarsal bones, and are rigidly fixed to the proximo-palmar or -plantar edge of the proximal phalanx.
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Associated Genetic Factors: LBX1 and Mox2 In specific muscle formation, mutations in associated genetic factors begin to affect specific muscular regions. Because of its large responsibility in the movement of dorsal muscles into the limb following delamination, mutation or deletion of Lbx1 results in defects in extensor and hindlimb muscles. As stated in the Proliferation section, Mox2 deletion or mutation causes abnormal patterning of limb muscles. The consequences of this abnormal patterning include severe reduction in size of hindlimbs and complete absence of forelimb muscles.
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It has been suggested that the long, powerful forelimbs of Heterodontosaurus may have been useful for tearing into insect nests, similarly to modern anteaters. These forelimbs may have also functioned as digging tools, perhaps for roots and tubers. Tianyulong restoration The length of the forelimb compared to the hindlimb suggests that Heterodontosaurus might have been partially quadrupedal, and the prominent olecranon process and hyperextendable digits of the forelimb are found in many quadrupeds. However, the manus is clearly designed for grasping, not weight support.
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Cast of the skull shown from the right Originally, only one or possibly two individuals of Saurornithoides were known, closely associated within the same layer of the Djadochta Formation of Mongolia. The fossils were found on 9 July 1923 by a Chinese employee of an American Museum of Natural History expedition, Chih. The material contained a single skull and jaw in association, and vertebrae, a partial pelvis, hindlimb and foot associated nearby. More bones were initially included but later shown to belong to Protoceratops.
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In general, subjects in bed rest studies do not exhibit increases in ventricular ectopy, although numerous studies have shown decreases in left ventricular mass and/or volume. During bed rest, left ventricular mass has been shown to decrease by eight percent after 6 weeks, which was thought to be related to decreased physiological loading. Ground- based animal studies also have been used to determine the effects of microgravity on the cardiovascular system. Tachycardia has been observed in standing rats, after hindlimb-unloading for 28 days.
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Cetiosauriscus ( ) is a genus of sauropod dinosaur that lived between 166 and 164 million years ago during the Callovian (Middle Jurassic Period) in what is now England. A herbivore, Cetiosauriscus had—for sauropod standards—a moderately long tail, and longer forelimbs, making them as long as its hindlimbs. It has been estimated as about long and between in weight. The only known fossil that was later named Cetiosauriscus includes most of the rear half of a skeleton as well as a hindlimb (NHMUK R3078).
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Rayanistes was capable of extensive power strokes during pelvic paddling, based on the robust hindlimb and innominate. The more abducted orientation of its femur allowed for greater maneuverability of the hip joint in contrast to that of Remingtonocetus. The discovery of Rayanistes is significant because it shows that the most primitive non-pelagicete cetaceans were becoming widespread beyond the southern margin of the ancient Tethys sea.Ryan M. Bebej, Iyad S. Zalmout, Ahmed A. Abed El-Aziz, Mohammed Sameh M. Antar and Philip D. Gingerich (2016).
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In a Ficus racemosa, in Polo Forest, Sabarkantha, Gujarat, India This is a large species, with a head and body length of about 43 cm and a tail of 50–52 cm. It has black to gray-brown fur, long and soft on the upper parts and somewhat shorter underneath the body, with a grizzled appearance. A wing membrane between the forelimb and hindlimb, paler coloured underneath, allows gliding between trees. The tail is hairy and blackish to gray-brown, the feet are black, and the nose is pale pink with black vibrissae.
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This specimen PMU 24706, formerly PMU 234, comprises nine articulated dorsal vertebrae and the sacrum, two dorsal ribs, a nearly complete pelvis, and a right hindlimb lacking the fifth metatarsal and several pedal phalanges."Euhelopus." In: Dodson, Peter & Britt, Brooks & Carpenter, Kenneth & Forster, Catherine A. & Gillette, David D. & Norell, Mark A. & Olshevsky, George & Parrish, J. Michael & Weishampel, David B. The Age of Dinosaurs. Publications International, LTD. p. 70. . Both specimens are housed in the collection of the Paleontological Museum of Uppsala University, in Uppsala, Sweden, where the mounted skeletons are displayed since the 1930s.
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The encoded proteins of Tbx5 and Tbx4 play a role in limb development, and play a major role in limb bud initiation specifically. For instance, in chickens Tbx4 specifies hindlimb status while Tbx5 specifies forelimb status. The activation of these proteins by Hox genes initiates signaling cascades that involve the Wnt signaling pathway and FGF signals in limb buds. Ultimately, Tbx4 and Tbx5 lead to the development of apical ectodermal ridge (AER) and zone of polarizing activity (ZPA) signaling centers in the developing limb bud, which specify the orientation growth of the developing limb.
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They however, disagreed with Therizinosaurus as a segnosaurian taxon since it was known from forelimb material; they corroborated the referred hindlimb material as segnosaurian though. Lastly, Barsbold and Maryańska noted the striking similarities between the pelvises of Nanshiungosaurus and Segnosaurus, such as the opisthopubic condition and large iliac blade. They concluded that the former was part of the Segnosauridae. Skeletal composite of two specimens of Alxasaurus With the description of the therizinosauroids Alxasaurus in 1993 by Dale A. Russell and Dong Zhiming, the affinities of the group were fairly more clear.
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Analysis of pachycephalosaurid skull by Mallon and Evans, suggest many species frequently inhibited coastal area contrary to their terrestrial life style. In the same study, it was concluded that North American pachycephalosaurids lived in habitats near flood plains and coastal plains. Hindlimb proportions have been found to be similar to other modern animals such as moose and various wading birds that inhibit wetland areas. The Milk River Formation, where A. audeti is found, is home to many other extinct species in the late Cretaceous including other dinosaurs like Saurornitholestes and mammals like Alphadon.
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However, it was previously argued that they were hindlimb dominant like other sauropods, and thus had the ability to rear up on their hindlimbs. Based on the structure of their legs, making it impossible for them to run, it is likely that they moved about in a low walking speed (20–40 km/day), but were capable of moving faster when necessary, up to 20–30 km/hour, depending on leg length. Brachiosaurids shared synapomorphies, new traits typical for the group. They possessed middle and rear back vertebrae with long, 'rod-like' transverse processes.
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This is caused by the evolution of Hox genes, controlling limb morphogenesis. The axial skeleton of the snakes’ common ancestor, like most other tetrapods, had regional specializations consisting of cervical (neck), thoracic (chest), lumbar (lower back), sacral (pelvic), and caudal (tail) vertebrae. Early in snake evolution, the Hox gene expression in the axial skeleton responsible for the development of the thorax became dominant. As a result, the vertebrae anterior to the hindlimb buds (when present) all have the same thoracic-like identity (except from the atlas, axis, and 1–3 neck vertebrae).
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Of the hindlimb, the femur was very similar to that of Giraffatitan although slightly more robust, and measured long. As in Giraffatitan, it was strongly elliptical in cross-section, being more than twice as wide in front or back view than in side view. The fourth trochanter, a prominent bulge on the back side of the femoral shaft, was more prominent and located further downward. This bulge served as anchor point for the most important locomotory muscle, the caudofemoralis, which was situated in the tail and pulled the upper thigh backward when contracted.
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Amphibians exhibit classic wiping and withdrawal protective motor responses to noxious chemical, heat and mechanical stimuli. Acetic acid (a strong irritant) applied to the hindlimb of frogs elicits vigorous wiping of the exposed skin; both pH and osmolarity may contribute to the nociception produced. This response is used in a standard test for analgesic effects in frogs, commonly termed the "acetic acid test". In this procedure, dilutions of the acid are placed drop-wise on the dorsum of the frog's thigh until the frog wipes the affected area.
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Similarly, digit II of the foot in Sinusonasus is not as specialized as those of derived troodontids, despite the hindlimb being overall derived. Conversely, the forelimb of Jianianhualong is short overall as in derived troodontids, despite the presence of basal traits. An ancestral state reconstruction conducted along with the phylogenetic analysis (results labelled in the above phylogenetic tree) suggests that wing feather asymmetry evolved only once, at the last common ancestor of the Paraves. Asymmetrical tail feathers would then also have evolved once, at the common ancestor of all paravians excluding scansoriopterygids and avialans.
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Several amateur paleontologists, among them Keith and Jenny Simmonds, now began to search for additional remains of the predator. Ultimately, the total of secured bones included the snout, teeth, a front lower jaw, most of the vertebral column, ribs, belly ribs, chevrons, the left shoulder girdle, pelvis bones and a hindlimb. These were accessioned under numbers BMNH R10001 and MIWG 6348. They equalled approximately 70% of the skeleton. In 1985, excavations undertaken by Dr Steve Hutt of the MIWG revealed two vertebrae of a second individual, specimen MIWG.5470.
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He characterized elasmosaurids by their long necks and small heads, as well as by their rigid and well- developed scapulae (but atrophied or absent clavicles and interclavicles) for forelimb-driven locomotion. Meanwhile, pliosaurids had short necks but large heads, and used hindlimb-driven locomotion. Although the placement of Elasmosaurus in the Elasmosauridae remained uncontroversial, opinions on the relationships of the family became variable over subsequent decades. Williston created a revised taxonomy of plesiosaurs in 1925. In 1940 Theodore White published a hypothesis on the interrelationships between different plesiosaurian families.
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The holotype specimen, UMNH VP 21400, hails from the Hayden- Corbett site of the Cedar Mountain Formation of Utah, approximately eight miles southeast from the city of Green River. The specimen was unearthed from a higher stratigraphic level (upper Yellow Cat Member) than Falcarius. The generic name, Martharaptor, is in honor to the paleontologist assistant Martha C. Hayden who helped in the discovery of the site, and the specific name, greenriverensis, is a reference to the Green River. The specimen includes fragments of vertebrae, a scapula, forelimb and hindlimb bones, and an ischium.
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Its forearm was as long as the upper arm, unlike most other sauropods, resulting in a forelimb equalling the hindlimb in length. Its thigh bone was approximately six feet long. Skeletal drawing of C. oxoniensis In his original descriptions, Owen was unable to indicate any differences between Cetiosaurus and other sauropods for the simple reason these latter were not yet discovered. Now that such relatives have been found, the uniqueness of Cetiosaurus oxoniensis and its status as a valid taxon must be proven by indicating its new derived traits or autapomorphies.
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Before limb development begins, T-box proteins initiate FGF10 expression in the proliferating mesenchymal cells of the lateral plate mesoderm, which form the limb bud mesoderm. WNT2B and WNT8C stabilize this FGF10 expression in the forelimb and hindlimb, respectively. This FGF10 expression stimulates WNT3 expression in the above ectodermal cells – resulting in formation of the apical ectodermal ridge as well as inducing FGF8 expression. The FGF8 secreted by the AER acts to keep the cells of the limb mesenchyme in a mitotically active state and sustains their production of FGF10.
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Holotype material of O. velox The history of Ornithomimus classification, and the classification of ornithomimids in general, has been complicated. The type species, Ornithomimus velox, was first named by O.C. Marsh in 1890, based on syntypes YPM 542 and YPM 548, a partial hindlimb and forelimb found on 30 June 1889 by George Lyman Cannon in the Denver Formation of Colorado. The generic name means "bird mimic", derived from Greek ὄρνις, ornis, "bird", and μῖμος, mimos, "mimic", in reference to the bird-like foot. The specific name means "swift" in Latin.
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Docofossor was at least nine centimetres long, exempting the tail, and weighed at least nine grams, perhaps sixteen. It had a skeletal structure and body proportions strikingly similar to the modern day African golden mole. It had shovel-like fingers for digging, short and wide upper molars typical of mammals that forage underground, and a sprawling posture indicative of subterranean movement. The sprawling is proven by a short hindlimb of just twenty-three millimetres, a massive olecranon as an adaptation for digging and a projecting parafibula forcing the knee joint into a bent position.
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The species name romeri honors influential 20th-century vertebrate paleontologist Alfred Sherwood Romer. Dromomeron and type species D. romeri are based on GR 218, a complete left thigh bone from the Hayden Quarry at Ghost Ranch, New Mexico. The rocks there are in the lower portion of the Petrified Forest Member of the Chinle Formation, and are Norian in age. Additional hindlimb bones, some probably from the same individual, are also known, and a partial skeleton has been recovered from Hayden Quarry, but has not yet been fully prepared.
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Majungasaurus is classified as a member of the theropod clade Abelisauridae, which is considered a family in Linnaean taxonomy. Along with the family Noasauridae, abelisaurids are included in the superfamily Abelisauroidea, which is in turn a subdivision of the infraorder Ceratosauria. Abelisaurids are known for their tall skulls with blunt snouts, extensive sculpturing on the outer surfaces of the facial bones (convergent with carcharodontosaurids), very reduced (atrophied) forelimbs (convergent with tyrannosaurids), and stocky hindlimb proportions, among other features. As with many dinosaur families, the systematics (evolutionary relationships) within the family Abelisauridae are confused.
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The hindlimb elements were generally very robust. The proportions of the legs, pelvis and sacrum of the Rodrigues and red rail were generally similar. The Rodrigues rail differed from the red rail by having a broader and shorter skull, longer and lower nostrils, a proportionately longer humerus, a shorter, stouter femur, as well as a considerably different plumage, based on early descriptions. The Dutch ornithologist Marc Herremans suggested in 1989 that the Rodrigues and red rails were neotenic, with juvenile features such as weak pectoral apparatuses and downy plumage.
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The genus is based on one partial skeleton, holotype IVPP 12579, which consists of a series of 41 caudal vertebrae and an incomplete left hindlimb. Its remains were recovered in the summer of 1999 at the "Middle Gray unit" of the Xinminbao Group in the Gongpoquan Basin in Gansu, China. The type species, Gobititan shenzhouensis was named and described by You, Tang and Luo in 2003 and was classified as a basal titanosaur. This specimen is housed in the collection of the Institute of Vertebrate Paleontology and Paleoanthropology, in Beijing, China.
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Yet more recent analysis of its axial and appendicular skeleton—particularly the vertebrae and femur—suggests that it was a tree-dweller (arboreal). Like the ruffed lemurs, Pachylemur was also an arboreal quadruped that frequently exhibited hindlimb suspension in order to reach fruit and leaves on smaller branches. However, Pachylemur was a slow, deliberate climber unlike the ruffed lemurs, which leap and bound through the upper canopy. Like the both living lemurs and extinct lemurs, Pachylemur likely conserved energy because of its diet, small brain, and slow climbing.
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Like living ruffed lemurs, Pachylemur specialized in eating fruit, and was therefore an important seed disperser, possibly for tree species with seeds too large for even ruffed lemurs to swallow. In the spiny thickets of southwestern Madagascar, they were also likely to have dispersed seeds evolved to attach to fur and be carried away. Unlike ruffed lemurs, the fore- and hindlimbs of Pachylemur were nearly the same length, and therefore it was likely to be a slow, deliberate climber. However, both used hindlimb suspension to reach fruit on small branches below them.
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This is due to the humerus of Panderichthys being a shape that is more of an intermediate, while the femur is more primitive because of the length ratio to the fibula and that it lacks an adductor blade and crest. This implies that Panderichthys was not capable of tetrapod-like hindlimb propelled locomotion because of its small pelvic fins, non-weight bearing pelvic girdle, acetebelum oriented posteriorly, and limited knee and elbow flexion.Boisvert, Catherine A. "The pelvic fin and girdle of Panderichthys and the origin of tetrapod locomotion." Nature 438.7071 (2005): 1145-1147.
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This is caused by the evolution of their Hox genes, controlling limb morphogenesis. The axial skeleton of the snakes’ common ancestor, like most other tetrapods, had regional specializations consisting of cervical (neck), thoracic (chest), lumbar (lower back), sacral (pelvic), and caudal (tail) vertebrae. Early in snake evolution, the Hox gene expression in the axial skeleton responsible for the development of the thorax became dominant. As a result, the vertebrae anterior to the hindlimb buds (when present) all have the same thoracic-like identity (except from the atlas, axis, and 1–3 neck vertebrae).
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Plastic model of a herd in the JuraPark in Solec Kujawski, Poland Vulcanodons limbs were sturdy and column-like, and its forelimbs were already proportionally long, reaching 76% of hindlimb length. Its lower leg, metatarsus, and toes were shortened in comparison to its bipedal ancestors, but still not as short as in later sauropods. The sacrum was made out of four fused sacral vertebrae; "prosauropods" possessed only three sacrals. The tail vertebra bodies already showed an incipient excavation of their lateral sides, saving weight and giving them a waisted appearance when viewed from below.
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Like other members of their family, Therizinosaurus had a proportionally small skull bearing a keratinous beak atop the long neck, with bipedal gaits and a heavy, broad belly for foliage processing with the addition of sparse feathering. Its hindlimbs ended in four functionally, weight-bearing toes unlike other theropod groups in which the first toe was reduced to a dewclaw. In 2010, Senter and James used hindlimb length equations to predict the total length of the hindlimbs in Therizinosaurus and Deinocheirus. They concluded that an average Therizinosaurus may have had approximately long legs.
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The type specimen MDT-PV 1/48, discovered in the Bajo Barreal Formation, consists of an articulated right hindlimb, which includes the femur, fibula, tibia and foot. The longest femur discovered for this genus measures 247mm, and the longest tibia, 270mm. On average, the tibia is 13% longer than the femur in Aniksosaurus, an adaptation which has been strongly correlated with the development of cursorial habits in dinosaurs. Martinez and Novas (2006), based on femoral measurements, originally suggested that Aniksosaurus darwini was approximately long and tall at the hip, and weighed up to .
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Although CK is required for the biosynthesis of PC, CK is normally present in excess and so is not generally considered the rate- limiting step. Researchers have concluded, however, that due to the reduced activity of CK seen in the hindlimb muscle of the CKβ knockout mice model, CK is probably the rate-limiting enzyme in skeletal muscles. This suggests that defect in CKβ may lead to a decrease in PC synthesis in the muscles resulting in muscular dystrophy. These results suggest that CK could possibly play a vital role in the homeostasis of PC.
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The specific name tenerensis is after the Ténéré Desert where the animal was found. alt= The holotype, MNN GDF500, was found in the Tegama Beds of the Elrhaz Formation. It consists of a partial skeleton lacking the skull. It contains three neck ribs, parts of fourteen dorsal (back) vertebrae, ten dorsal ribs, gastralia (or "belly ribs"), pieces of three sacral vertebrae, parts of twelve caudal (tail) vertebrae, chevrons (bones that form the underside of the tail), a scapula (shoulder blade), a coracoid, a partial forelimb, most of the pelvis (hip bone), and parts of a hindlimb.
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Tbx4 is a transcription factor and member of the T-box family, which have been shown to play important role in fetal development. Tbx4 is expressed in a wide variety of tissues during organogenesis, including the hindlimb, proctodeum, mandibular mesenchyme, lung mesenchyme, atrium of the heart and the body wall. Tbx4 is specifically expressed in the visceral mesoderm of the lung primordium and governs multiple processes during respiratory tract development such as initial endodermal bud development, respiratory endoderm formation, and septation of the respiratory tract and esophagus. Along with Tbx4, Tbx5 is also expressed to help with development of limbs.
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Limb elements: (a) humerus, (b) femur, (c) entire hindlimb The interclavicle is a large plate with a smooth upper surface and a prominent groove on the bottom surface. It also bears a small, pointed projection at its back end. The scapulae have prominent shelves on each side (diagnostic of leptocleidids and polycotylids, but not strongly differentiated in elasmosaurids), and their glenoids are clearly concave, with roughened attachments for cartilage. The two coracoids curve outwards in the middle and contact at their ends, forming a hole in the middle, although the exact morphology of this hole is uncertain.
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Mierasaurus is an extinct genus of sauropod dinosaur from the Early Cretaceous of Utah, United States. The taxon was first described and named in 2017 by Rafael Royo-Torres and colleagues, from a mostly complete skeleton including a disarticulated partial skull and mandible, teeth, multiple vertebrae from along the length of the body, both scapulae, radius and ulna bones, a left manus, a complete pelvis, both femora and the entire left hindlimb. Additionally, they also referred a lower jaw and femur from juvenile individuals, which were found nearby, to the genus. Collectively, Mierasaurus is among the most completely known North American sauropods.
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Over 60 percent of the wing length is occupied by the wing fingers, making them among the longest possessed by any pterodactyloids. In adult ornithocheirids, the sacrum develops a supraneural plate above its neural spines. The tails of ornithocheirids are poorly known, though they appear to be composed of at least eleven short vertebrae, and become relatively circular in cross section toward the end of the series. Like the related istiodactylids, the slender femora of ornithocheirids have femoral heads that project almost in line with the femoral shaft, but seem to lack prominent processes that anchor their hindlimb muscles.
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The talar features which distinguish Cebupithecia from other pitheciines indicate that leaping was relatively more frequent, as is also indicated by other postcranial features. The locomotor behavior of Cebupithecia has been reconstructed as frequent quadrupedalism and leaping, or more relying on vertical clinging and leaping rather than quadrupedal locomotion, much like members of the extant genus Pithecia, to which the genus is related.Tejedor, 2013, p.28 Later research suggests that Cebupithecia may have employed its tail differently than most nonprehensile-tailed platyrrhines living today, behaviors that possibly involved tail-bracing or twisting during hindlimb (pedal grasping) suspensory behaviors.
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Reconstruction of Halszkaraptor escuilliei, with plumage and swimming posture based on aquatic birds that use wing-propelled swimming Halszkaraptor had characteristics that allowed it to spend time both in water and on land, including strong hindlimbs for running and smaller flipper-like forelimbs for swimming. The short tail would have brought the centre of gravity more to the front, which is more useful for swimming than walking. The torso would have been held more vertical than is normal with theropods. To this end, there are adaptations for an improved extension of the hindlimb, in the hip joint and the thighbone.
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Cat hindlimb musculoskeletal model with redundant degrees of freedom at muscles (red lines) and joints One of the largest difficulties in motor control is quantifying the exact number of DOFs in the complex neuromuscular system of the human body. In addition to having redundant muscles and joints, muscles may span multiple joints, further complicating the system. Properties of muscle change as the muscle length itself changes, making mechanical models difficult to create and understand. Individual muscles are innervated by multiple nerve fibers (motor units), and the manner in which these units are recruited is similarly complex.
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The vertebrate land invasion refers to the aquatic-to-terrestrial transition of vertebrate organisms in the Late Devonian epoch This transition allowed animals to escape competitive pressure from the water and explore niche opportunities on land. Fossils from this period have allowed scientists to identify some of the species that existed during this transition, such as Tiktaalik and Acanthostega. Many of these species were also the first to develop adaptations suited to terrestrial over aquatic life, such as neck mobility and hindlimb locomotion. The late Devonian vertebrate transition was preceded by the plant and invertebrate terrestrial invasion.
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Comparison between the cervicals of Erketu and other sauropodomorphs Size comparison with a human Erketu was a relatively large sauropod, with an estimated length of and a weight of . Its neck was estimated to be twice as long as its body, which may be a record for neck to body ratio. The exact ratio is unknown, because no dorsal vertebrae of E. ellisoni have been reported, although some hindlimb material suggests the approximate size of the body. The long neck of Erketu is the result of the individual vertebrae being greatly elongated; it is unknown if the number of cervical vertebrae was increased.
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Stephen Reily and Thomas White, Hypaxial Motor Patterns and the Function of Epipubic Bones in Primitive Mammals, ARTICLE in SCIENCE 299(5605):400-2 · FEBRUARY 2003, Department of Biological Sciences, Ohio University, Athens, OH 45701, USA. Impact Factor: 33.61 · · Source: PubMed These pelvic bones strengthen the torso and support abdominal and hindlimb musculature. They, however, prevent the expansion of the abdomen, and so force species that possess them to either give birth to larval young (as in modern marsupials), or produce minuscule eggs that hatch into larval young (as in modern monotremes).Michael L. Power, Jay Schulkin.
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The hindlimb elements were discovered in place, although they were weathered; the tail vertebrae were out of place, and the last vertebra in the sequence was found several meters away from the rest of the specimen. In 2017, Paul Sereno published a description of MNBH GAD112 as the holotype specimen of a new genus and species, Afromimus tenerensis. The genus name combines the Latin prefix Afro- ("Africa") and the Greek word mimos ("mimic"), in reference to the interpretation of the specimen as a member of the Ornithomimosauria. The species name combines the name of the Ténéré Desert and the Latin suffix -ensis ("from").
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Ubiquitin-specific protease 14 is an enzyme that in humans is encoded by the USP14 gene. This gene encodes a member of the ubiquitin-specific processing (UBP) family of proteases that is a deubiquitinating enzyme (DUB) with His and Cys domains. This protein is located in the cytoplasm and cleaves the ubiquitin moiety from ubiquitin-fused precursors and ubiquitinylated proteins. Mice with a mutation that results in reduced expression of the ortholog of this protein are retarded for growth, develop severe tremors by 2 to 3 weeks of age followed by hindlimb paralysis and death by 6 to 10 weeks of age.
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Size comparison Cetiosaurus, or specifically the neotype species C. oxoniensis, is known from relatively complete fossils. These include the three skeletons found by Phillips. One of these is a larger animal (catalogued as OUMNH J13605–13613, J13615–16, J13619–J13688 and J13899), which was chosen by Upchurch & Martin as the lectotype of the species; the second consists of limb bones of a smaller individual (OUMNH J13614) and the third skeleton represents the shoulder blade and hindlimb of a juvenile animal (OUMNNH J13617–8, J13780–1). The Rutland specimen, about 40% complete, increases considerably the number of known skeletal elements, especially in the neck.
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Mesopropithecus and its closest sloth lemur relative, Babakotia, did share a few ancestral traits with indriids, unlike the largest sloth lemurs, Palaeopropithecus and Archaeoindris. These include the aforementioned four- toothed toothcomb, an inflated auditory bulla (bony structure that encloses part of the middle and inner ear), and an intrabullar ectotympanic ring (bony ring that holds the eardrum). While the skull of Mesopropithecus most closely resembles that of modern sifakas, the postcranial skeleton is quite different. Rather than having elongated hindlimbs for leaping, Mesopropithecus had elongated forelimbs, suggesting they predominantly used quadrupedal locomotion, slow climbing, with some forelimb and hindlimb suspension.
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The digits also have a quasi-periodic arrangement along the proximodistal axis, consisting of tandem chains of skeletal elements. The generation of the basic limb plan during development results from the patterning of the mesenchyme by an interplay of factors that promote precartilage condensation and factors that inhibit it. The development of the basic limb plan is accompanied by the generation of local differences between the elements. For example, the radius and ulna of the forelimb, and the tibia and fibula of the hindlimb of the zeugopod are distinct from one another, as are the different fingers or toes in the autopod.
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When beads were placed in the middle of the flank tissue, the anterior portion expressed Tbx5 and forelimb features, while the posterior portion of the limb expressed Tbx4 and hindlimb features. #When chick embryos were engineered to constitutively express Tbx4 (via viral- transfection) throughout their flank tissue, every limb they grew was a leg, even those that formed in the anterior region, which would normally become wings. This confirms the role of T-box proteins in the type of limb that develops. #Knocking out Tbx4 or Tbx5 knockout prevents FGF10 expression in the lateral plate mesoderm in mice.
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It has been shown that both electrical contraction and AICA ribonucleotide (AICAR) treatment increase AMPK activation, glucose uptake, and GLUT-4 translocation in perfused rat hindlimb muscle, linking exercise-induced glucose uptake to AMPK. Chronic AICAR injections, simulating some of the effects of endurance training, also increase the total amount of GLUT-4 protein in the muscle cell. Two proteins are essential for the regulation of GLUT-4 expression at a transcriptional level – myocyte enhancer factor 2 (MEF2) and GLUT4 enhancer factor (GEF). Mutations in the DNA binding regions for either of these proteins results in ablation of transgene GLUT-4 expression.
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The second fossil, VMNH 3650, is sometimes considered a paratype and is more complete, only missing part of the tail as well as the left hindlimb. The Solite quarry was once a large lake and surrounding wetland which formed in a rift when Pangaea started to break up during the Late Carnian stage of the Triassic, about 230 million years ago. It held abundant populations of insects and the tanystropheid reptile Tanytrachelos. The fossils of the Solite quarry are often preserved as dark grey bones embedded in dark grey mudstone, and are thus usually very difficult to observe and prepare.
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Nhandumirim is known from a single partial skeleton, LPRP/USP 0651, which includes several vertebrae, a right ilium, and most of a right hindlimb. This skeleton was found at the site of Waldsanga (also known as Cerro da Alemoa or Sanga do Mato) in Santa Maria, Rio Grande do Sul. Waldsanga is a historically important Triassic site which also preserved the type specimens of Saturnalia, Rauisuchus, Gomphodontosuchus, and Alemoatherium. The site preserves Carnian-age sediments of the Santa Maria Formation, and LPRP/USP 0651 specifically comes from the top of the Alemoa member on that site.
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Associated Genetic Factors: c-Met/HGF and LBX1 Mutations in these genetic factors causes a lack of migration. LBX1 is responsible for the development and organization of muscles in the dorsal forelimb as well as the movement of dorsal muscles into the limb following delamination. Without LBX1, limb muscles will fail to form properly; studies have shown that hindlimb muscles are severely affected by this deletion while only flexor muscles form in the forelimb muscles as a result of ventral muscle migration. c-Met is a tyrosine kinase receptor that is required for the survival and proliferation of migrating myoblasts.
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The holotype, MACN PV N53, which was collected in March 1983 by José Fernando Bonaparte, consists of two tail vertebrae, a right ischium, and a partial right hindlimb. Although classified as a titanosaur in the original description, the titanosaur placement of Amargatitanis was subsequently questioned by later authors, who noted that a scapula (MACM PV N34) and six tail vertebrae (MACN PV N51) seen as syntypes of Amargatitanis were found at a different locality than MACN PV N53 and that putative titanosaur characters of the genus were invalid. A 2016 re-evaluation by Pablo Ariel Gallina reclassified Amargatitanis as a dicraeosaurid.
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Hulsanpes has been re-classified as a halszkaraptorine taxon, updating various aspects about the life-style of these animals. Hulsanpes had a similar life-style to those of the modern-day sawbills or waterfowls, spending most of their time in aquatic environments (such as rivers) using fore and hindlimb-assisted swimming. But like all dinosaurs, they come up onto land to reproduce and layed eggs in terrestrial nests. However, it appears to be that Hulsanpes may have been more terrestrial halszkaraptorines based on the holotype metatarsus, which features adaptations for a more subcursorial life-style, supporting the diversification within this subfamily.
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The generic name is derived from Chinese xiáo, 曉, "dawn", a reference to the age of the fossil. The specific name refers to Danshanpu.Dong Z. & Tang Z., 1983, "New ornithopod genus from the Middle Jurassic of Sichuan Basin, China", Vertebrata PalAsiatica 21(2): 168-171 The holotype, IVPP V6730A, was found in the lower Xiashaximiao Formation of which the age is uncertain: both the Bajocian and the Bathonian–Callovian have been proposed. It consists of a partial skeleton including a jaw fragment with a single tooth, two cervical vertebrae, four caudal vertebrae, a humerus, a partial left femur and a complete right hindlimb.
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Life restoration of Scleromochlus, a likely early avemetatarsalian commonly considered close to pterosaurs. Two researchers, S. Christopher Bennett in 1996, and paleoartist David Peters in 2000, published analyses finding pterosaurs to be protorosaurs or closely related to them. However, Peters gathered novel anatomical data using an unverified technique called "Digital Graphic Segregation" (DGS), which involves digitally tracing over images of pterosaur fossils using photo editing software. Bennett only recovered pterosaurs as close relatives of the protorosaurs after removing characteristics of the hindlimb from his analysis, to test the possibility of locomotion-based convergent evolution between pterosaurs and dinosaurs.
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The skull of MPC-D 100/86 is mostly undistorted and well preserved, lacking only the tip of the snout, while the rest of the skeleton is missing only middle cervical vertebrae, forelimb bones located lower than the elbow joints, some hindlimb bones, and most gastralia. It was discovered by a Japanese-Mongolian expedition, and represents the most complete specimen of a Late Cretaceous troodontid presently known. It was collected from the Dzamin Khond locality of the Djadokhta Formation in the central Gobi Desert, dating to the late Campanian stage of the Late Cretaceous, approximately 72 million years ago.
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"KT events in India: impact, rifting, volcanism and dinosaur extinction," in Novas & Molnar, eds., Proceedings of the Gondwanan Dinosaur Symposium, Brisbane, Memoirs of the Queensland Museum, 39(3): iv + 489–731 : 489-532 However, this claim was rejected by Galton and Upchurch (2004), who noted that the skull, tooth and plate of Dravidosaurus are certainly not plesiosaurian as illustrated. Galton and Ayyasami (2017) reaffirmed the stegosaurian classification of Dravidosaurus, claiming the remains do not look like plesiosaurian pelvic and hindlimb elements. They announced that stegosaurian remains from the Dravidosaurus type locality are under study by one of the original describers of Dravidosaurus.
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Woodward, Keeper of Geology at the NHMUK, had "great pleasure" to recommend to the Trustees of the NHMUK the fossil be purchased. The purchase was sanctioned on 25 February 1899, along with the purchase of assorted other remains for just over £357 (~£43,596 now), where the Leeds sauropod gained the accession number BMNH R3078 (now NHMUK R3078). Known elements of Cetiosauriscus The amount of material made NHMUK R3078 the most complete sauropod specimen from the United Kingdom, comparable only later to the "Rutland Dinosaur" (referred to Cetiosaurus) discovered in 1967. Known regions of the specimen include the forelimb, hindlimb and vertebral column.
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Holtz noted that tyrannosaurids and some closely related groups had significantly longer distal hindlimb components (shin plus foot plus toes) relative to the femur length than most other theropods, and that tyrannosaurids and their close relatives had a tightly interlocked metatarsus (foot bones). The third metatarsal was squeezed between the second and fourth metatarsals to form a single unit called an arctometatarsus. This ankle feature may have helped the animal to run more efficiently. Together, these leg features allowed Tyrannosaurus to transmit locomotory forces from the foot to the lower leg more effectively than in earlier theropods.
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During embryonic development, the 21-kD protein FGF4 functions as a signaling molecule that is involved in many important processes. Studies using Fgf4 gene knockout mice showed developmental defects in embryos both in vivo and in vitro, revealing that FGF4 facilitates the survival and growth of the inner cell mass during the postimplantation phase of development by acting as an autocrine or paracrine ligand. FGFs produced in the apical ectodermal ridge (AER) are critical for the proper forelimb and hindlimb outgrowth. FGF signaling in the AER is involved in regulating limb digit number and cell death in the interdigital mesenchyme.
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Anatomical terms used to describe a human hand Several anatomical terms are particular to the hands and feet. For improved clarity, the directional term palmar () is usually used to describe the front of the hand, and dorsal is the back of the hand. For example, the top of a dog's paw is its dorsal surface; the underside, either the palmar (on the forelimb) or the plantar (on the hindlimb) surface. The palmar fascia is palmar to the tendons of muscles which flex the fingers, and the dorsal venous arch is so named because it is on the dorsal side of the foot.
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Life restoration by Emily Willoughby Yi qi, and presumably other scansoriopterygids, possessed a type of wing unknown among any other prehistoric bird relatives. Unlike other paravian dinosaurs, they seem to have replaced bird-like feathers with membranous wings, in what may have been one of many independent evolutionary experiments with flight close to the origin of birds. The membranous wings of Yi qi are unique among dinosaurs and difficult to interpret. That the arm could in principle function as a wing, is shown by being longer than the already elongated hindlimb and the sufficient thickness of its long bones.
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Parksosaurus has been considered to be a hypsilophodont since its description. Recent reviews have dealt with it with little comment, although David B. Norman and colleagues (2004), in the framework of a paraphyletic Hypsilophodontidae, found it to be the sister taxon to Thescelosaurus, and Richard Butler and colleagues (2008) found that it may be close to the South American genus Gasparinisaura. However, basal ornithopod phylogeny is poorly known at this point, albeit under study. Like Thescelosaurus, Parksosaurus had a relatively robust hindlimb, and an elongate skull without as much of an arched shape to the forehead compared to other hypsilophodonts.
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Daliansaurus is known from a single nearly- complete skeleton preserved in three dimensions. Parts of the specimen had been reconstructed and do not represent genuine fossil material, including the back of the skull and the rear portion of the lower jaw. Furthermore, the shoulder girdles are missing from the fossil, as is the right hindlimb; the left humerus, most of the pelvis, and the last few caudal vertebrae are buried in the surrounding matrix. The head and neck of the fossil are curled backwards, while the tail itself is curved forwards; the left arm is extended while the right arm is tucked inwards.
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Some hindlimb and pelvis bones from the Upper Weald Clay Formation (late Barremian) were referable to V. canaliculatus. Some material from the earlier Hastings Beds (Valanginian) were referred to a Valdosaurus sp. Galton established that Richard Owen had in 1842 been the first to describe Valdosaurus thighbones, specimens BMB 004297-004300, assigning them to Iguanodon. Galton emphasized that though the type femora were very small, fourteen centimetres long (which has led to estimates of a length of 1.2 metres and a weight of ten kilogramsPaul, G.S., 2010, The Princeton Field Guide to Dinosaurs, Princeton University Press p.
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At the same time, the skull and hindlimbs resemble derived troodontids: the deep jugal branch of the maxilla bearing a prominent groove, the sub-triangular antorbital fossa; the relatively long maxillary fenestra; the short jugal branch of the postorbital bone; the long hallux; the slender and short metatarsal II; the "heel" on phalanx II-2; and the large, curved sickle claw. Sinosonasus exhibits a similar condition: the skull is like those of basal troodontids, and the pelvis and hindlimb are like those of derived troodontids. Phylogenetically, Xu and colleagues found Jianianhualong in a polytomy with Sinusonasus and several other intermediate troodontids. The strict consensus tree recovered is reproduced below.
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Life restoration, based on the holotype specimen The lectotype AMNH 6554 is fragmentary, consisting of a nearly complete right hindlimb only lacking the distal tarsal elements; left metatarsals II, III and IV, and a fragmentary distal foot of a pubis, however it is unknown which pubis represents. It was a medium-sized tyrannosauroid, reaching a length between , and a weight ranging from . Genus List for Holtz 2012 Weight Information Overall, the hindlimbs were rather gracile, in contrast to the robust tyrannosaurids. The length of its tibia (shinbone) and femur (thighbone) are very close, in contrast to the majority of other tyrannosauroids, where the tibia is longer.
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Life restoration of the head The hindlimb of the specimen AMNH 6554 is notable for the particular elongated digits and metatarsals, differing from other tyrannosauroids. These traits are found in terrestrial runner birds, suggesting that Alectrosaurus was suited as a fast-running tyrannosauroid dinosaur with well developed hindlimbs; probably a pursuit predator. This interpretation is consistent with the results obtained in the limb proportion analysis performed by Scott Persons IV and Currie in 2016. By comparing the limbs of numerous theropods they noted that most tyrannosauroids were highly cursorial and leggy animals, with the exception of giant and stocky-legged forms such as Tarbosaurus or Tyrannosaurus.
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The Hox genes, which define features along the anterior-posterior axis of a developing organism, determine at which points along the axis that limb buds will form. Though limbs emerge at different locations in different species, their positions always correlate with the level of Hox gene expression along the anterior-posterior axis. All limb buds must also rely on other signaling factors to obtain their forelimb or hindlimb identity; Hox gene expression influences expression of T-box proteins that, in turn, determine limb identity for certain organisms. In turn, the activation of T-box protein activates signaling cascades that involve the Wnt signaling pathway and FGF signals.
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A total of eight specimens have been collected from the Dinosaur Park Formation over the years since, most of them within the boundaries of Dinosaur Provincial Park. Phil Currie believes that the Dinosaur Park specimens represent a new species of Daspletosaurus, distinguished by certain features of the skull. Pictures of this new species have been published, but it still awaits a name and full description in print. D. horneri holotype skull from Montana in Museum of the Rockies A new tyrannosaurid specimen (OMNH 10131), including skull fragments, ribs and parts of the hindlimb, was reported from New Mexico in 1990 and assigned to the now-defunct genus Aublysodon.
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Many features of the hindlimb, including the long tibia and foot, as well as the fusion of the tibiofibiotarsus and tarsometatarsus, indicate that heterodontosaurids were adapted to run quickly on the hindlegs, so it is unlikely that Heterodontosaurus moved on all four limbs except perhaps when feeding. The short tusks found in all known heterodontosaurids strongly resemble tusks found in modern musk deer, peccaries and pigs. In many of these animals (as well as the longer-tusked walrus and Asian elephants), this is a sexually dimorphic trait, with tusks only found in males. The type specimen of Abrictosaurus lacks tusks and was originally described as a female.
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Milton Hildebrand pioneered the contemporary scientific analysis and the classification of gaits. The movement of each limb was partitioned into a stance phase, where the foot was in contact with the ground, and a swing phase, where the foot was lifted and moved forwards. Each limb must complete a cycle in the same length of time, otherwise one limb's relationship to the others can change with time, and a steady pattern cannot occur. Thus, any gait can completely be described in terms of the beginning and end of stance phase of three limbs relative to a cycle of a reference limb, usually the left hindlimb.
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Artist's life restoration Tianyuraptor is a medium-sized dromaeosaurid that has several derived features that separate it from other dromaeosaurids. These include the length of the middle caudal (tail) vertebrae being more than twice that of the dorsal (back) vertebrae, a small and extremely slender furcula, and an unusually long hindlimb that is roughly three times as long as the entire series of dorsal vertebrae. As in other dromaeosaurid fossils discovered in Liaoning, the tail is relatively long at , nearly 4.8 times as long as the femur. The type specimen is STM1–3, a nearly complete and fully articulated skeleton that is only missing the extreme distal end of the tail.
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Size comparison In 1924, Heber Longman, self- trained paleontologist at (and later director of) the Queensland Museum in Brisbane, learned of a large fossil reptile skeleton exposed in the Walloon Coal Measures at the Durham Downs Station near Roma in central Queensland. The station manager, Arthur Browne, forwarded fragments of bone to Longman, and was honoured with the dinosaur's specific name brownei. The initial collection was of 22 tail vertebrae, including a series of 16 consecutive bones, and other fragmentary hindlimb pieces. Soon after Longman announced the new discovery, he visited the station and arranged for more material of the same skeleton to be sent to the Queensland Museum.
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The genus name Elaphrosaurus is derived from the Greek words elaphros (ελαφρός) meaning "light to bear" as in "light-footed", a reference to its presumed high running speed and "sauros" (σαῦρος) meaning "lizard"; thus, "light-footed lizard". The specific name honours the industrialist Paul Bamberg for his financial support of the Tendagaru expeditions. HMN Gr.S. 38-44 consists of 18 presacral vertebrae, 5 sacral vertebrae, 20 caudal vertebrae, a pelvic girdle, a nearly complete left hindlimb (missing only some phalanges), several isolated metacarpals, and a humerus. In 1925, Janesch referred two rib fragments, a dorsal vertebrae, and a manual phalanx he believed to be phalanx II-2.
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A hindlimb during excavation in the Tendaguru In 1906, mining engineer Bernhard Wilhelm Sattler, while travelling, noticed an enormous bone jutting out of the ground at the Tendaguru (the "steep hill") near Lindi, in what was then German East Africa, today Tanzania. In early 1907, his superior Wilhelm Arning in Hannover received a report on the find. Arning again informed the Kommission für die landeskundliche Erforschung der Schutzgebiete, a commission in Berlin overviewing the geographical investigation of German protectorates.Maier (2003), p 1 The German secretary of state of colonies, Berhard Dernburg, at the time visited German East Africa accompanied by the industrialist Heinrich Otto.
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However, the referral of the coracoid, pubes, and hindlimb material catalogued under IPHG 1912 VIII to Deltadromeus has been questioned because the remains came from different horizons and localities in the Bahariya Formation, and actually exhibit notable differences from the holotype of Deltadromeus. The Deltadromeus skeleton has been found in the same formation as those of the giant theropods Carcharodontosaurus, Spinosaurus, and Bahariasaurus, which may be synonymous with Deltadromeus. No skull material has been found for either Deltadromeus or Bahariasaurus, and though carnivore teeth labelled as "Deltadromeus" are commonly sold in rock shops, there is no way of knowing if they actually come from this animal.
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A single amino acid substitution was shown to cause major effects on neurovirulence. The mechanisms and determinants involved in Flavivirus neuroinvasiveness remains unknown. However, evidence suggests neuroinvasiveness depends entirely on envelope proteins E and prM (pre-membrane) In a study investigating the effects of MODV on hamsters, severe encephalitis, bilateral hindlimb paralysis, and complete paralysis with an intact corneal reflex were observed.. MODV-induced encephalitis in hamsters was characterized by movement of monocytes and lymphocytes into the cortex and bulbus olfactorius, causing massive destruction of the tissue structure. In all surviving hamsters, IgM and HI antibodies to MODV were present in the blood after subcutaneous infection.
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A rotated pelvis of Anhanguera santanae, showing its right side The pelvis of ornithocheiromorphs was of moderate size compared to the body as a whole, similar to other ornithocheiroids. The three pelvic bones were often fused, as seen in many species such as Anhanguera santanae, the ilium was long and low, and its front and rear blades projected horizontally beyond the edges of the lower pelvic bones. Despite the structure length, the processes of these rod-like forms indicate that the hindlimb muscles attached to them were limited in strength. The pubic bone was fused with the broad ischium into an ischiopubic blade, resulting in a narrow build.
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The hindlimbs of ornithocheiromorphs were strongly built, yet relative to their wingspans, smaller than those of birds in terms of hindlimb- to-wingspan ratio. The hindlimbs were long in comparison to the torso length, and the thighbone was rather straight, with the head making only a small angle with the shaft. This implied the legs not being held vertically below the body, but were somewhat sprawling within. A tibiotarsus is mostly seen in many ornithocheiromorphs, this consisted on the shinbone (tibia) being fused with the upper ankle bones, resulting in a longer structure than the thighbone, which could attain a vertical position when walking.
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Int J Obes 29:682–688 Hot peppers have been reported to induce thermogenesis at the cellular level.Yoshioka, M., Lim, K., Kikuzato, S., Kiyonaga, A., Tanaka H. and Shindo M. (1995) Effects of red-pepper diet on the energy metabolism in men, J Nutr Sci Vitaminol. 41:647–656Eldershaw T.P., Colquhoun E.Q., Bennett K.L., Dora K.A. and Clark M.G. (1994) Resiniferatoxin and piperine: capsaicin- like stimulators of oxygen uptake in the perfused rat hindlimb, Life Sci 55:389–397 As well, capsaicin induces satiety as a result of oral and gastro- intestinal contribution. Lower energy and fat intake were observed under short-term conditions; however, the effect of the spice was reduced over prolonged exposure.
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Rocks in the Doelling's Bowl bonebed mainly consist of green-grey sandy mudstone, but also contain silcrete, casts of silificied plant roots, and chert pebbles. It belongs to the Cretaceous-aged Yellow Cat Member of the Cedar Mountain Formation. Mierasaurus was named after Bernardo de Miera y Pacheco of the 1776 Dominguez- Escalante expedition (pictured here) In 2010, a skeleton of a subadult sauropod dinosaur was discovered in an arroyo within Gary's Island, a region at the western end of the bonebed named after its discoverer Gary Hunt. Only part of the specimen - a partial left forelimb (scapula, sternal plates, ulna, radius, and hand), a complete left hindlimb, and ten caudal (tail) vertebrae - was articulated.
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Hindlimb bones of ZPAL MgD-I/8, MEPAS; note arctometatarsalian foot The cervical vertebrae of Gallimimus indicate that it held its neck obliquely, declining upwards at an angle of 35 degrees. Osmólska and colleagues found that the hands of Gallimimus were not prehensile (or capable of grasping), and that the thumb was not opposable. They also suggested that the arms were weak compared to, for example, those of the ornithomimosaur Deinocheirus. They agreed with the interpretations of ornithomimid biology by palaeontologist Dale Russell from earlier in 1972, including that they would have been very fleet (or cursorial) animals, although less agile than large, modern ground birds, and would have used their speed to escape predators.
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A timeline depicting observed evidence of post-canine megadontia The shift towards post-canine megadontia dates back to about 4-5 million years ago with the discovery of Ardipithecus ramidus in the Middle Awash region of Ethiopia. Distinctive features in A. ramidus such as dentition with reduced canines, the skull, hindlimb and forelimb suggest it to be near the split between the chimpanzee and hominin lineages. It was the origin of Australopithecus africanus, found in several regions of South Africa (Taung, Sterkfontein, Makapansgat) 2-3 million years ago that first demonstrated the enlargement of the pre-molars and molars. In terms of morphology, A. africanus shares many similar characteristics with A. afarensis as well as other genera in Paranthropus.
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In particular, the features of the humerus suggest a great development of the pectoral and deltoid muscles, not only required to capture its prey, also to absorb the energy of the impact of the collision with such prey. Vertebrae The features of the hindlimb, with a robust femur equipped with a greater trochanter in the lower part, the short tibia and plantigrade feet shows that this animal was not a runner, and probably stalked its prey animals. The hindlimbs also allowed a certain mobility of the hip, and possibly the ability to stand up only with its hindlimbs, like Prothylacynus and Borhyaena. Contrary to felids, barbourofelids and nimravids, the claws of Thylacosmilus were not retractable.
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A full published description is still lacking, though an unpublished thesis on Orodromeus exists.Scheetz, R.D., 1999, Osteology of Orodromeus makelai and the phylogeny of basal ornithopod dinosaurs D. Ph. Thesis in Biology, Montana State University, Bozeman, 189 pp However, MOR 246 and other eggs from Egg Mountain are now considered to belong to a troodontid which may be Stenonychosaurus. In 1990, the species Laosaurus minimus, described by Charles Gilmore in 1909 based on NMC 9438, a partial left hindlimb and pieces of vertebra from the Allison Formation in Alberta, was noted as the second species of Orodromeus. The fragmentary nature of the remains, however, makes it difficult to assign the specimen with certainty.
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Study into Suminia post cranial anatomy reveal many autapomorphies for the single specimen. Significant post cranial autapomorphies of Suminia are the reduced number of presacral and dorsal vertebrae (exclusively amphicoelous) with lack of fusion in the sacral region between vertebrae (suggests high flexibility), wide pre- and postzygapophyses, longer proportions of cervical pleurocentra, distinct proportionally longer limbs, a manus that forms ~ 40% of the length of the forelimb with particularly long, curved terminal phalanges, a pes that makes up ~38% of the hindlimb, and enlarged carpal 1 and tarsal 1 (suggests divergent first digit). These different morphological features indicate a significantly deviated post cranial anatomy from other anomodonts, suggesting that Suminia adopted an arboreal lifestyle (see below).
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The only known specimen of Afromimus is a partial skeleton consisting of seven (originating from the middle of the tail and estimated to be the 15th, 16th, 18th, 20th, 22nd, 24th, and 27th tail vertebrae), bones from the right hindlimb (the , , , and ), and part of a rib, all found within a radius of . It was discovered in 1997 at the Gadoufaoua locality in the Elrhaz Formation, in the Ténéré Desert of Niger. The specimen is catalogued as MNBH GAD112 in the Musée National Boubou Hama, the national museum of Niger in the city of Niamey. Since the specimen was exposed to the elements when it was found, it may have been more complete when it was still buried.
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Marsh (1878a) named his new genus from vertebrae (YPM 1874) found by Samuel Wendell Williston at Como Bluff, Wyoming, from rocks of the Morrison Formation. The type material includes nine partial and two complete tail vertebral centra, which he concluded came from a "fox-sized" animal. In the same year, he named two other species: L. gracilis, originally based on a back vertebral centrum, a tail vertebral centrum, and part of an ulna; and L. altus, originally based on a pelvis, hindlimb, and tooth (YPM 1876). A review by Peter Galton in 1983 found the type of L. gracilis to consist of thirteen back and eight tail centra, and portions of both hindlimbs.
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Gilmore also described the fifth and final species, L. minimus (species name for its small size), based on NMC 9438, a partial left hindlimb and vertebral bits from the Late Cretaceous (late Campanian) Allison Formation of Alberta, Canada. At the time, though, the discovery locality was thought to be in the Early Cretaceous Blairmore Group, but fieldwork at the L. minimus type locality in the early 1930s showed it to be within the Belly River Group, and Loris Russell published a paper in 1949 recognizing this new geologic information, while finding it generically distinct from Laosaurus proper. Russell found this taxon to be most like Hypsilophodon, from the Early Cretaceous Wessex Formation of southern England.
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The species name refers to the National Institute of Standards and Technology (NIST). Discovered by Siegwarth and Filla in upper Morrison Formation beds at Como Bluff, Wyoming, it was based on a partial subadult skeleton (listed as CPS 106 originally, then as Tate 4001 by Bakker 1996) including partial jaws, vertebrae, and partial limbs. Several other specimens found in the same area were assigned to it, mostly consisting of vertebral and hindlimb remains, and teeth. The holotype specimen's current location is unknown; according to Carpenter and Galton (2018), the previous two institutions reported to have had it did not ever curate the specimen, and the collection it was originally said to be in never existed at all.
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Metacarpal III (the third bone of the hand) was as long as if not longer than metacarpal IV (the fourth bone of the hand), as with tanystropheids. Hindlimb bones are overall fairly typical in structure, although the femur (thigh bone) was broader than in most reptiles. The ankle was formed by four tightly-connected bones: the centrale, astragalus, calcaneum, and distal tarsal IV. Although the astragalus and calcaneum were the most prominent bones in the ankle, all of the ankle bones were similar in size. Boreopricea also lacked a hole along the contact between the astragalus and calcaneum and the second phalanx (toe bone) of the fifth toe was long, both traits shared by tanystropheids.
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Enaliarctos has been heralded as the ancestor of all known pinnipeds, including the families Otariidae (fur seals and sea lions), Desmatophocidae (extinct seal convergent pinnipeds), Phocidae (true seals), and Odobenidae (walruses). Investigations of the biomechanics of Enaliarctos indicate that it used both its forelimbs and hindlimbs during swimming. Modern fur seals and sea lions only use their forelimbs, while true seals primarily use their hindlimbs for aquatic propulsion; lastly, the extant walrus uses both fore- and hindlimbs for swimming. It has been postulated that the condition in Enaliarctos is ancestral for all pinnipeds, and that forelimb swimming was lost in true seals, while hindlimb swimming was lost in fur seals and sea lions.
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A 2007 reply by Dave Hone and Michael Benton could not reproduce this result, finding pterosaurs to be closely related to dinosaurs even without hindlimb characters. They also criticized David Peters for drawing conclusions without access to the primary evidence, that is, the pterosaur fossils themselves. Hone and Benton concluded that, although more basal pterosauromorphs are needed to clarify their relationships, current evidence indicates that pterosaurs are avemetatarsalians, as either the sister group of Scleromochlus or a branch between the latter and Lagosuchus. An 2011 archosaur-focused phylogenetic analysis by Sterling Nesbitt benefited from far more data and found strong support for pterosaurs being avemetatarsalians, though Scleromochlus was not included due to its poor preservation.
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Karin Peyer, in 2006, reported skin impressions preserved on the side of the tail starting at the 13th tail vertebra. The impressions showed small bumpy tubercles, similar to the scales found on the tail and hind legs of Juravenator. Additional scales had in 1901 been reported by Von Huene, in the abdominal region of the German Compsognathus, but Ostrom subsequently disproved this interpretation; in 2012 they were by Achim Reisdorf seen as plaques of adipocere, corpse wax. Like Compsognathus, and unlike Sinosauropteryx, a patch of fossilized skin from the tail and hindlimb of the possible relative Juravenator starki shows mainly scales, though there is some indication that simple feathers were also present in the preserved areas.
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The hindlimb structure of Ambulocetids shows that their ability to engage in terrestrial locomotion was significantly limited compared to that of contemporary terrestrial mammals, and likely did not come to land at all. The skeletal structures of the knee and ankle indicates that the motion of the hindlimbs was restricted into one plane. This suggests that, on land, propulsion of the hindlimbs was powered by the extension of dorsal muscles. They probably swam by pelvic paddling (a way of swimming which mainly utilizes their hind limbs to generate propulsion in water) and caudal undulation (a way of swimming which uses the undulations of the vertebral column to generate force for movements), as otters, seals and modern cetaceans do.
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From reconstructions of the skeleton, Coelurus had a relatively long neck and torso due to its long vertebrae, a long slender hindlimb due to its long metatarsus, and potentially a small slender skull. Coelurus compared in size to an average adult human The skull is unknown except for possibly a portion of lower jaw found at the same site as the rest of the known Coelurus material. Although it has the same preservation and coloring as the fossils known to belong to the Coelurus skeleton, it is very slender, which may mean it does not belong to the skeleton; this bone is 7.9 centimeters long (3.1 in) but only 1.1 centimeters tall (0.43 in).
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Most of its preserved elements are very robust, an unusual trait in dromaeosaurs, which were generally lightly built animals. Achillobator is classified as a dromaeosaurid taxon, more specifically within the Eudromaeosauria, a group of hypercarnivore dromaeosaurids that were mainly terrestrial instead of arboreal or amphibious. In most cladistic analyses Achillobator is recovered as a close relative of Dromaeosaurus and Utahraptor, although it is often considered to be the sister taxon of the latter. The stocky and short hindlimb ratio of Achillobator indicates that it was not cursorial—an animal adapted for speed or to mantain high speeds—moreover, the robust morphology of the maxilla suggests a predatory behavior based on large- sized prey.
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These evolved into the sauropods which became gigantic quadrupedal herbivores, some of which reached lengths of at least 26 m (85 ft). Features defining this clade include a ratio of forelimb length to hindlimb length greater than 0.6. Most sauropods still had hindlimbs larger than forelimbs; one notable exception is Brachiosaurus whose long forelimbs suggest that it had evolved to feed from tall trees like a modern-day giraffe. Sauropod fossils are found from the times of the earliest dinosaurs right up to the Cretaceous–Paleogene extinction event, from 227 to Ma. Most sauropods are known from the Jurassic, to be more precise between 227 and 121 Ma. The Cretaceous sauropods form two groups.
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During the same year and also from Hermiin Tsav, the specimen IGM 100/45 was discovered by the Joint Soviet- Mongolian Paleontological Expedition. Unlike the previous findings, this specimen is represented by a hindlimb composed of a very fragmented femur with tibia, astragalus, calcaneum, a lower tarsal, a tetradacyl pes compromising four partial metatarsals, nearly complete digits I, II and IV (although II and IV are missing the unguals) and the presumed second phalanx from the digit III. These newer remains were described by the also Mongolian paleontologist Altangerel Perle in 1982. He referred the specimen to Therizinosaurus based on the striking resemblance to Segnosaurus, another therizinosaurid genus also known from limb elements.
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Front of reconstructed skeleton, Rocky Mountain Dinosaur Resource Center Thescelosaurus has generally been allied to Hypsilophodon and other small ornithopods as a hypsilophodontid, although recognized as being distinct among them for its robust build, unusual hindlimbs, and, more recently, its unusually long skull. Peter Galton in 1974 presented one twist to the classic arrangement, suggesting that because of its hindlimb structure and heavy build (not cursorial, or built for running, by his definition), it should be included in the Iguanodontidae. This has not been followed, with Morris arguing strongly against Galton's classification scheme. At any rate, Galton's Iguanodontidae was polyphyletic and not a natural group, and so would not be recognized under modern cladistic usage.
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Referred hindlimb elements Tethydraco was placed in the family Pteranodontidae; it would have been the youngest known member of that family, since its fossil remains dated back 66 million years ago. Its existence was seen as proof that pterosaur diversity in the Maastrichtian was higher than previously assumed. Pterosaur decline was an illusion caused by the Signor–Lipps effect, groups seeming to disappear earlier than a mass extinction because their youngest fossils by chance have been found at somewhat older layers than the extinction event. Below is a cladogram showing the results of a phylogenetic analysis first presented by Andres and colleagues in 2014, and updated with additional data by Longrich and colleagues in 2018.
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Albertonykus (meaning "Alberta claw") is an alvarezsaurid dinosaur from the Maastrichtian-age (Upper Cretaceous) rocks of the Horseshoe Canyon Formation of Alberta, Canada. It is known from forelimb and hindlimb remains from multiple individuals. All but two of the specimens come from a bonebed dominated by Albertosaurus, located located at the top of Unit 4 of the Horseshoe Canyon Formation,Larson, D. W., Brinkman, D. B., & Bell, P. R. (2010). Faunal assemblages from the upper Horseshoe Canyon Formation, an early Maastrichtian cool-climate assemblage from Alberta, with special reference to the Albertosaurus sarcophagus bonebed This article is one of a series of papers published in this Special Issue on the theme Albertosaurus.
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Restoration of Batrachotomus Hip joint and hindlimb postures of (1) "sprawling" amniotes (lizards and crocodilians) (2) "erect" amniotes (mammals and dinosaurs), and (3) "pillar-erect" amniotes ("rauisuchians" and aetosaurs) The hip of Prestosuchus (AMNH 3856) "Rauisuchians" had an erect gait with their legs oriented vertically beneath the body rather than sprawling outward. This type of gait is also seen in dinosaurs, but evolved independently in the two groups. In dinosaurs, the hip socket faces outward and the femur (thigh bone) connects to the side of the hip; while in rauisuchians, the hip socket faces downward to form a shelf of bone under which the femur connects. This has been referred to as the pillar-erect posture.
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Silhouette reconstruction of the skeleton of L. marayensis Skull of L. marayensis in dorsal view Leyesaurus is known from the holotype PVSJ 706, a nearly complete skull with articulated mandible and some postcranial remains (vertebral column, scapular and pelvic girdles and hindlimb). The skull has a length of 18 centimeters, and Leyesaurus has been estimated to have been about in length. It was collected from the uppermost part of the Quebrada del Barro Formation of the Marayes-El Carrizal Basin, dating to the Lower Jurassic (based on the presence of a massospondylid like Leyesaurus within the formation). Leyesaurus was found near the locality Balde de Leyes, in the Caucete Department of San Juan Province.
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"Comanchesaurus" is an informal name for fossilized remains from the Late Triassic of New Mexico that were initially interpreted as belonging to a theropod dinosaur. The remains, NMMNH P-4569, consist of a partial skeleton including vertebral centra and hindlimb bones, and came from the Norian-age Upper Triassic Bull Canyon Formation of Guadalupe County. Adrian Hunt, in his unpublished dissertation, proposed the name "Comanchesaurus kuesi" for the specimen, but the name was never adopted, and was first referred to in the scientific literature in a 2007 redescription of Late Triassic North American material thought to belong to dinosaurs (Nesbitt, Irmis, and Parker, 2007). In the redescription, the authors found the material to belong to a "possible indeterminate saurischian".
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Carpenter suggested in 1982 that the heavily vascularized armor may also have had a role in thermoregulation as in modern crocodilians. Restoration of Ankylosaurus displaying its tail club The tail club of Ankylosaurus seems to have been an active defensive weapon, capable of producing enough of an impact to break the bones of an assailant. The tendons of the tail were partially ossified and were not very elastic, allowing great force to be transmitted to the club when it was used as a weapon. Coombs suggested in 1979 that several hindlimb muscles would have controlled the swinging of the tail, and that violent thrusts of the club would have been able to break the metatarsal bones of large theropods.
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This study concluded that Australovenator's flexibility, facilitated by a combination of traits in both primitive and advanced theropods, played a role in prey capture, giving it the ability to grasp prey towards its chest to make it easier for its weak jaws to disembowel food. A 2016 study used CT scans of an emu foot to digitally reconstruct the musculature and soft tissue of an Australovenator foot, as well as determine how soft tissue affects flexibility. The study determined that muscular range of motion is often overestimated when not accounting for soft tissue, and that soft tissue reconstruction is vital for making future analyses of theropod flexibility more accurate. A review of hindlimb elements described in 2013 re-identified several phalanges which were initially positioned incorrectly.
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The species name is a reference to the song "Waltzing Matilda", written by Banjo Paterson in Winton, while the generic name is derived from the Diamantina River, running nearby the type locality combined with the Greek sauros, meaning "lizard". AODF 603, the holotype, includes the right scapula, both humeri, right ulna, both incomplete hands, dorsal ribs and gastralia, partial pelvis, and the right hindlimb missing the foot. The paratype, under the same specimen, includes dorsal and sacral vertebrae, the right sternal plate now thought to represent the remainder of a coracoid, a radius, and one manual phalanx. All these bones come from AODL 85, nicknamed the "Matilda Site" at Elderslie Sheep Station, located about west-northwest from Winton in central Queensland.
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Qianxisaurus is known solely from the holotype NMNS-KIKO-F044630, a nearly complete and articulated skeleton missing only the tip of the tail and the right hindlimb, housed at the National Museum of Natural Science in Taichung, Taiwan. The holotype is exposed mostly in a view from above, with the tail gradually turning to left side view. The skull measures at 7.6 cm in length, and the total length of the preserved parts of the individual is 76.8 cm. Only the first 31 tail vertebrae are preserved, out of at least 42-48 vertebrae that are expected to comprise the tail based on other closely related pachypleurosaurs, which implies a total body length longer than 80 cm for this individual.
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The type material of Najash is the only possible madtsoiid specimen retaining evidence of pelvic and hindlimb elements, which are claimed to be more plesiomorphic than other Cretaceous limbed snakes, such as Pachyrhachis, Haasiophis or Eupodophis, in retaining a sacro-iliac contact and well-developed limbs, with a huge and well-defined trochanter. The sacro iliac contact is perhaps misleadingly described by Apesteguía and Zaher as unique possession of a sacrum, whereas it has rarely been questioned that the cloacal vertebrae in snakes are homologous to the sacrals of limbed squamates (i.e. the sacrum is present but has lost contact with the reduced ilia in other taxa). It would be unsurprising if other madtsoiids also possessed hindlimbs as complete as those of Najash.
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In terms of hindlimb proportions, Teleocrater is more similar to silesaurids, pseudosuchians, and early archosaurs than lagerpetids or ornithodirans, in that the metatarsus is not particularly lengthened with respect to the femur and tibia. The lengthening of the metatarsus in the latter groups probably represent adaptations to running. The femur of Teleocrater shows a combination of diverse characteristics. Like other aphanosaurians, the top end of the femur bears a transverse groove, and also bears a scar for the attachment of the iliofemoralis externus muscle that is connected to the intermuscular line; the same condition is seen with the anterior trochanter in dinosaurmorphs, yet the scar is clearly separated from that of the iliotrochantericus caudalis as it is in Dongusuchus, Yarasuchus, and early archosaurs.
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Tribosphenid mammals were originally grouped on the basis of triangular or V-shaped (tribosphenic) molars. Since then, other unrelated mammal groups have been found to have tribosphenic molars, such as the australosphenidans (a group that includes the still extant monotremes), suggesting that as a synapomorphy this is fundamentally useless as it evolved multiple times among mammals. However, a clade between the aforementioned groups, the "true Tribosphenida" or Boreosphenida, is still identifiable, united by characteristics such as the lack of a mesial cingulid and of a triangulated trigonid on the last premolar. They are also united by postcranial features such as the presence of a modern ear (though this too has evolved independently in many other groups, like monotremes), modern shoulder blades, and several features of the hindlimb.
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Nhandumirim (meaning "small rhea" in the Tupi language) is a genus of saurischian dinosaur from the Carnian age of Late Triassic Brazil. The type and only species, Nhandumirim waldsangae, is known from a single immature specimen including vertebrae, a , pelvic material, and a hindlimb found in the Santa Maria Formation in Rio Grande do Sul. Nhandumirim is differentiated from other Santa Maria dinosaurs such as Staurikosaurus and Saturnalia on the basis of its more gracile, long-legged proportions and several more specific skeletal features. It also possessed several unique features compared to other early dinosaurs, such as long keels on vertebrae at the base of the tail, a straight metatarsal IV, and a short brevis fossa of the ilium and dorsolateral trochanter of the femur.
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Data from extant birds suggested that the medullary bone in this Allosaurus individual may have been the result of a bone pathology instead. However, with the confirmation of medullary tissue indicating sex in a specimen of Tyrannosaurus, it may be possible to ascertain whether or not the Allosaurus in question was indeed female. Restoration of a juvenile Allosaurus The discovery of a juvenile specimen with a nearly complete hindlimb shows that the legs were relatively longer in juveniles, and the lower segments of the leg (shin and foot) were relatively longer than the thigh. These differences suggest that younger Allosaurus were faster and had different hunting strategies than adults, perhaps chasing small prey as juveniles, then becoming ambush hunters of large prey upon adulthood.
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S. cutleri holotype specimen NHMUK R5161 at Natural History Museum, London Scolosaurus was named by Franz Nopcsa von Felső-Szilvás in 1928, based on holotype NHMUK R.5161, a nearly complete specimen that preserves the entire skeleton except for the distal end of the tail, the right forelimb, the right hindlimb, and the skull. The rare preservation of osteoderms and skin impression are also present. The fossil skeleton was discovered by William Edmund Cutler, an independent fossil collector in 1914 at Quarry 80 of the Deadlodge Canyon locality. It was collected from the bottom of the Dinosaur Park Formation in fine-grained sandstone and fine-grained claystone sediments that were deposited during the Campanian stage of the Late Cretaceous period, approximately 76.5 million years ago.
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Several paleontologists consider Coelophysis bauri to be the same dinosaur as Coelophysis rhodesiensis (formerly Syntarsus, alternately Megapnosaurus), however this has been refuted by the following: Downs (2000) concluded that C. bauri differs from C. rhodesiensis in cervical length, proximal and distal hindlimb proportions and proximal caudal vertebral anatomy;Downs, A. (2000). "Coelophysis bauri and Syntarsus rhodesiensis compared, with comments on the preparation and preservation of fossils from the Ghost Ranch Coelophysis quarry": In: Tykoski and Rowe (2004) concluded that C. bauri differs from C. rhodesiensis in that it lacks a pit at the base of the nasal process of the premaxilla; and Bristowe and Raath (2004) concluded that C. bauri differs from C. rhodesiensis in having a longer maxillary tooth row.
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Because the Erlikosaurus specimen lacked a pelvis, the authors were unsure that the undetermined segnosaurian could belong to the same genus, in which case they would consider it part of a separate family. Though Erlikosaurus was difficult to compare directly to Segnosaurus because its remains were incomplete, Perle stated in 1981 there was no justification for separating it into another family. Therizinosaurus, the first known therizinosaur, was originally known only from forelimb bones from Mongolia (cast shown here, in Aathal Dinosaur Museum), which created confusion about its affinities with other theropods. In 1982, Perle reported the discovery of hindlimb fragments similar to those of Segnosaurus and assigned them to Therizinosaurus, whose forelimbs had been found in almost the same location.
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This skull was recognized as an unnamed hypsilophodont for many years, until Galton made it the type specimen of new genus and species Bugenasaura infernalis ("large-cheeked lizard belonging to the lower regions", infernalis being a reference to the Hell Creek Formation). Morris also named a new possible species of Thescelosaurus for specimen LACM 33542: ?T. garbanii (with a question mark because he was uncertain that it belonged to the genus). LACM 33542 comprised a large partial hindlimb ("a third larger than described specimens of T. neglectus and Parksosaurus or nearly twice as large as Hypsilophodon") including a foot, tarsus, shin bones, and partial thigh bone, along with five cervical (neck) and eleven dorsal (back) vertebrae, from the Hell Creek Formation of Garfield County, Montana, USA.
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Given the role of the MLR in gait initiation and postural control, researchers and clinicians have investigated the effects of targeted deep brain stimulation (DBS) on gait disturbances in clinical populations. Plaha and Gill reported significant improvements in gait dysfunction and postural instability in two patients with advanced Parkinson's disease who were treated using DBS electrodes implanted in the region of the PPN. Likewise, in a more recent study, six patients with Parkinson's disease demonstrated improvements in posture, gait, and postural stability following 6 months of DBS to the PPN and subthalamic nucleus. Bachmann and colleagues applied DBS to the MLR in rats with chronic, incomplete spinal cord injury and reported improved hindlimb function and near normal restoration of locomotor function following treatment.
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Lagerpeton fossils have only been collected from the Chañares Formation in La Rioja Province, Argentina. The first of these fossils were discovered in a 1964-1965 expedition by the Museum of Comparative Zoology (MCZ) and Museo de la Plata (MLP), although some were also discovered in 1966 by paleontologists from the Miguel Lillo Institute (PVL) of the University of Tucuman. Alfred Romer named Lagerpeton chanarensis in 1971, based on a complete right hindlimb discovered during the MCZ-MLP expedition. The specimen was initially stored at the Museo de la Plata with catalogue number MLP 64-XI-14-10, but by 1986 it had been transferred to the Paleontology Museum at the National University of La Rioja (PULR) and given the designation PULR 06, though some studies alternatively call it UPLR 06 or UNLR 06.
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The earliest known sea cows, of the families Prorastomidae and Protosirenidae, are both confined to the Eocene, and were about the size of a pig, four-legged amphibious creatures. By the time the Eocene drew to a close, came the appearance of the Dugongidae; sirenians had acquired their familiar fully aquatic streamlined body with flipper-like front legs with no hind limbs, powerful tail with horizontal caudal fin, with up and down movements which move them through the water, like cetaceans. The last of the sirenian families to appear, Trichechidae, apparently arose from early dugongids in the late Eocene or early Oligocene. The current fossil record documents all major stages in hindlimb and pelvic reduction to the extreme reduction in the modern manatee pelvis, providing an example of dramatic morphological change among fossil vertebrates.
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Material from this specimen was originally spread across three institutions. Most of the back vertebrae, ribs, pelvis, hindlimb and most of the tail stayed at the University of Utah, while the neck vertebrae, some back vertebrae, the shoulder girdle and forelimb were shipped to the National Museum of Natural History in Washington D.C., and a small section of tail vertebrae ended up in the Carnegie Museum in Pittsburgh. However, in 1929 Barnum Brown arranged for all of the material to be shipped to the American Museum of Natural History in New York City, where it remains today. A cast of this specimen (AMNH 6341) was controversially mounted in the lobby of the American Museum, rearing up to defend its young (AMNH 7530, now classified as Kaatedocus siberi) from an attacking Allosaurus fragilis.
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Lehman for describing for the first time vertebrate material from the Triassic of Algeria. The holotype of Jesairosaurus lehmani is ZAR 06, a partial skeleton including an articulated and three-dimensionally preserved skull, pectoral girdle, cervical (neck) vertebrae, and a partial left humerus (forearm bone). It is also known from nine paratypes including ZAR 07 (a partial skull), ZAR 08 (a partial skull and postcranial skeletons), ZAR 09 (two partial postcranial skeletons), and ZAR 10-15, various postcranial material including vertebrae, pectoral and pelvic girdles, and even a partial hindlimb in ZAR 15. These specimens were collected in the Gour Laoud, locality 5n003 from the base of lower sandstones of the Lower Zarzaïtine Formation of Zarzaïtine Series, dating to the Anisian-Olenekian stages of the Early to the Middle Triassic.
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In terms of limb proportions, Zhao indicated that the forelimb of Klamelisaurus was three-quarters the length of the hindlimb, and the ulna and tibia were respectively two-thirds the lengths of the humerus and femur. He considered these proportions to be distinguishing characteristics of Klamelisaurus. According to Zhao, Klamelisaurus had a thin, elongated scapula and a slender, small coracoid (the former being 4.3 to 4.5 times the length of the latter), but Moore and colleagues did not consider his measurements of the scapula to be reliable as most of the bone was covered by plaster and paint. The , located at the outer bottom end of the scapula, was broader than in Cetiosaurus, Shunosaurus, and many early-diverging sauropodomorphs, and the top edge of the acromion was straight, not concave like Tienshanosaurus.
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This mirrored the contours of the maxilla of the upper jaw, and the strong expansion of the rear skull; this was similar to Bistahieversor, Tyrannosaurus, and Tarbosaurus, but unlike other tyrannosauroids. The dentary was also deep at the rear end, indicating that the following part of the mandible was comparable to Tarbosaurus and Tyrannosaurus in depth, but not to other tyrannosaurids. Like other tyrannosaurids, the behind the dentary had a deep and well-developed shelf just in front of where the jaw articulated with the skull, and Lythronax was similar to Tyrannosaurus in that this shelf had a concave upper surface. Life restoration showing hypothetical feathers Though the postcranial skeleton of Lythronax is poorly known, the known remains of the pubis (part of the pelvis) and the hindlimb show features typical within Tyrannosauridae.
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Swift and smart, like its North American cousin Troodon, Saurornithoides probably scoured the Gobi Desert, looking for small mammals or reptiles to eat. Like other troodontids, it had an enlarged retractable claw on the second toe of each foot, that in this case was of moderate size though rather curved. A juvenile specimen of S. mongoliensis was described in 1993 and gave insights into the life history of the species as well as its relatives; the highly ossified hindlimb suggested that Saurornithoides and other troodontids were well developed at birth and that they probably required little to no parental care. A revision of the genus in 2009 provided a differential diagnosis, a list of traits in which Saurornithoides differed from certain relevant relatives, especially concentrating on determining its place in the evolutionary tree.
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CEUM 8786, a left femur from an adult, was discovered later in Carol's Site, and was not described until 2012. At the same time, the Oklahoma Museum of Natural History (OMNH) had recovered remains belonging to the same hadrosauroid from excavations in the southwestern region of the Swell. Specimens discovered by the OMNH initially consisted of six individuals from five localities: two juvenile skeletons, including vertebrae, scapulae, an ulna, an ilium and ischium, and hindlimb elements from locality OMNH v237; a partial juvenile skeleton, including parts of the skull, forelimbs, and hindlimbs along with a dorsal vertebra from OMNH v824; OMNH 27749, a sacrum and ischium from OMNH v696; OMNH 24389, an ischium from OMNH v214; and OMNH 32812, a partial skeleton including a scapula, two caudal vertebrae, and other unexcavated elements from OMNH v866.
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Size of two Thescelosaurus species (right) compared to its relatives Parksosaurus (center) and Orodromeus (left), as well as a human Overall, the skeletal anatomy of this genus is well documented, and restorations have been published in several papers, including skeletal restorations and models. The skeleton is known well enough that a detailed reconstruction of the hip and hindlimb muscles has been made. The animal's size has been estimated in the 2.5–4.0 m range for length (8.2–13.1 ft) for various specimens, and a weight of 200–300 kilograms (450–660 pounds), with the large type specimen of T. garbanii estimated at 4–4.5 meters (13.1–14.8 feet) long. As discussed more fully under "Discovery, history, and species", it may have been sexually dimorphic, with one sex larger than the other.
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The posture of Thrinaxodon is an interesting subject, because it represents a transition between the sprawling behavior of the more lizard-like pelycosaurs and the more upright behavior found in modern, and many extinct, Mammalia. In cynodonts such as Thrinaxodon, the distal femoral condyle articulates with the acetabulum in a way that permits the hindlimb to present itself at a 45-degree angle to the rest of the system. This is a large difference in comparison to the distal femoral condyle of pelycosaurs, which permits the femur to be parallel with the ground, forcing them to assume a sprawling-like posture. More interesting is that there is an adaptation that has only been observed within Thrinaxodontidae, which allows them to assume upright posture, similar to that of early Mammalia, within their burrows.
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Hypselosaurus (meaning 'highest lizard', from Greek ὑψηλός meaning 'high' or 'lofty' and σαυρος meaning 'lizard') is a dubious genus of titanosaurian sauropod that lived in southern France during the Late Cretaceous, approximately 70 million years ago in the early Maastrichtian. Hypselosaurus was first described in 1846, but was not formally named until 1869, when Phillip Matheron named it under the binomial Hypselosaurus priscus. The holotype specimen includes a partial hindlimb and a pair of caudal vertebrae, and two eggshell fragments were found alongside these bones. Because of the proximity of these eggshells to the fossil remains, many later authors, including Matheron and Paul Gervais, have assigned several eggs from the same region of France all to Hypselosaurus, although the variation and differences between these eggs suggest that they do not all belong to the same taxon.
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The Ichthyosauromorpha are an extinct clade of marine reptiles consisting of the Ichthyosauriformes and the Hupehsuchia, living during the Mesozoic. The node clade Ichthyosauromorpha was first defined by Ryosuke Motani et. al. in 2014 as the group consisting of the last common ancestor of Ichthyosaurus communis and Hupehsuchus nanchangensis, and all its descendants. Their synapomorphies, unique derived traits, include: the presence of an anterior flange on the humerus and radius; the lower end of the ulna being as wide as or wider than the upper end, the forelimb being as long as or longer than the hindlimb, the hand having at least three quarters of the length of the upper arm and lower arm combined, the fibula extending behind the level of the thighbone, and the transverse process of the vertebral neural arch being reduced or absent.
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WGSC V26003 was discovered in Yangping, a town in Yuan’an County in Hubei Province, Central China, and excavated by Chinese paleontologists Xiao-hong Chen and Long Cheng in 2011. Despite being exposed at the surface when discovered, the specimen is largely articulated and moderately complete, preserving much of the head, trunk, left pectoral girdle, and left forelimb, and parts of the left hindlimb and the anterior part of the tail. However, several of the preserved elements have been extensively damaged by erosion, including the left pelvic girdle, and other elements were completely destroyed by erosion before discovery, including the tips of the jaws. The genus was named and formally diagnosed in a 2014 paper published in the open access journal PLOS One by paleontologists Xiao-hong Chen, Ryosuke Motani, Long Cheng, Da-yong Jiang, and Olivier Rieppel.
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Unlike limb development in tetrapods, where the forelimb and hindlimb buds emerge at roughly the same timepoint, the pelvic fin bud emerges much later than the pectoral fin. While the pectoral fin bud is apparent at 36 hours post fertilization (hpf) in zebrafish, the pelvic fin bud is only clear at around 21 days post fertilization (dpf), roughly when the animal is 8 mm in length. The pelvic fin appears at roughly 21 days post fertilization in zebrafish In zebrafish, the pelvic fin bud starts as a mesenchymal condensation that forms an apical ectodermal thickening. A fin fold forms from this thickening, which is then invaded by migratory mesenchyme, separating the fin bud into the proximal mesenchyme (which will give rise to the endoskeletal girdle and radials) and the distal mesenchyme (which will give rise to dermal fin rays).
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Walker, A., 1964, "Triassic reptiles from the Elgin area: Ornithosuchus and the origin of carnosaurs", Philosophical Transactions of the Royal Society of London B 248: 53-134 The name Lametasaurus now designated the scutes only and was generally considered to represent a member of the Nodosauridae. The pelvis and hindlimb bones have in 2003 been suggested to belong to Rajasaurus.J.A. Wilson, P.C. Sereno, S. Srivastava, D.K. Bhatt, A. Khosla and A. Sahni, 2003, "A new abelisaurid (Dinosauria, Theropoda) from the Lameta Formation (Cretaceous, Maastrichtian) of India", Contributions from the Museum of Paleontology, University of Michigan 31(1): 1-42 In 2008 Matthew Carrano e.a. discarded the possibility the scutes were ankylosaurian, stating they were probably titanosaurian or perhaps abelisaurid, in which latter case the species would possibly not have been a chimera in the first place and be a possible senior synonym of Indosaurus and/or Rajasaurus.
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The forelimb lacks the manus (hand) and part of the radius and ulna, although the hindlimb lacks only a few bones in the pes (foot) and fragments of the tibia, fibula and ilium. The vertebrae known are four parts of dorsal vertebrae, the neural spines of the sacrum, multiple anterior caudal vertebrae (tail bones), and a series of 27 nearly complete vertebrae from the middle of the tail with associated or articulated chevrons (ribs along the underside of the tail), although the vertebral series is not continuous. A tail tip (NHMUK R1967) from the same locality, but a different individual was thought by palaeontologist Alan Charig in 1980 to belong to Cetiosauriscus. The assignment of NHMUK R1967 to Cetiosauriscus was considered unlikely in alternate studies by palaeontologists Friedrich von Huene, Paul Upchurch and Darren Naish because of the lack of overlap and uncertain phylogenetic positions.
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Size of Parksosaurus (center) compared to its relatives Thescelosaurus (right) and Orodromeus (left), as well as a human Explicit estimates of the entire size of the animal are rare; in 2010 Gregory S. Paul estimated the length at 2.5 meters, the weight at forty-five kilograms.Paul, G.S., 2010, The Princeton Field Guide to Dinosaurs, Princeton University Press p. 277 William Parks found the hindlimb of his T. warreni to be about the same length overall as that of Thescelosaurus neglectus (93.0 centimeters (3.05 ft) for T. warreni versus 95.5 centimeters (3.13 ft) for T. neglectus), even though the shin was shorter than the thigh in T. neglectus, the opposite of T. warreni. Thus, the animal would have been comparable to the better-known Thescelosaurus in linear dimensions, despite proportional differences (around 1 meter (3.3 ft) tall at the hips, 2-2.5 meters (6.56-8.2 ft) long).
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In addition the referred material consists of two isolated teeth, a middle cervical vertebra, five back vertebral arches, a single right dorsal rib, three tail vertebrae, a left clavicle, a distal right humerus, a left ulna, possibly the fourth right middle hand bone, three ischia, a left and a right shinbones, and two hindlimb first claws. The remains are considered to be conspecific with the holotype due to their close association (in an area of three to three and a half meters) in fine and stable sandstone, their consistent morphology, and the fact the same elements from different individuals show no conflict in traits. The remains were collected on the farm Spion Kop 932, in a quarry located just over a kilometer East-North East another dinosaur rich quarry in a higher stratigraphic position within the probably Sinemurian part of the upper Elliot Formation, that yielded the less advanced sauropodomorphs Aardonyx celestae and the much smaller Arcusaurus pereirabdalorum.
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This species is distinguished from Calotes aurantolabium in having smooth dorsals, dorsal body scales unequal, upper six scale rows larger, remainder equal in size to ventral scales; three enlarged scales on caudal thigh; dorsal head scales obtusely keeled; parietal ridge raised; enlarged scale between nuchal crest and tympanum; antehumeral pit present; toe-IV longer than III; stretched hindlimb reaches eye. Distinguished from Calotes versicolor and Calotes liocephalus groups and C. rouxi and C. ellioti in presence of enlarged keeled scales on caudal surface of thigh. Distinguished from Calotes versicolor group lizards in scale orientation – distinguished from Calotes versicolor in having an antehumeral pit; distinguished from C. nemoricola and C. grandisquamis in having equal size dorsal and ventral scales, toe-IV longer than III, scales around midbody 67 (36-43 and 27-35 respectively); distinguished from C. calotes in lacking flattened spines above tympanum. Distinguished from C. ellioti and C. rouxi in having an antehumeral pit and in lacking spines.
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This specimen was collected and taken to the MNHN by the fifth expedition in 1972. Following a subsequent Italian-French expedition led by Taquet and Italian palaeontologist Giancarlo Ligabue that turned up a potential additional iguanodontian specimen, Ligabue offered to donate the nearly complete specimen and a skull of Sarcosuchus to the Municipality of Venice, which accepted the offer and subsequently mounted the skeleton in 1975 at the Museo di Storia Naturale di Venezia. Taquet formally described the two mostly-complete specimens MNHN GDF 300 and MNHN GDF 381 from the first and fourth expeditions as Ouranosaurus nigeriensis in 1976, along with a referred coracoid and femur that bore the numbers MNHN GDF 301 and MNHN GDF 302 respectively. MNHN GDF 300 was made the holotype, and was the primary specimen described, including a semi-articulated skull lacking the left , right and the , almost the entire vertebral column, forelimbs lacking a few hand bones, and most of the right hindlimb and a few bones of the left.
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Foulke contacted paleontologist Joseph Leidy, and together they recovered 8 teeth from the maxillar and dentary areas, dental battery fragments, left maxilla fragments, 3 partial dorsal vertebrae, 13 caudal centra including an almost complete middle caudal vertebra and other fragments, partial right coracoid, left humerus, left radius, left ulna, left ilium, right ischium, right partial pubis, the left hindlimb composed by the femur, tibia, fibula with metatarsals II and IV and the first pedal phalanx from the third digit. Foulke and Leidy studied the fossils together, and in 1858, Leidy formally described and named Hadrosaurus foulkii in honor of his collaborator. Hadrosaurus is derived from the Greek , , meaning "bulky" or "large", and , , meaning "lizard". Leidy recognized that these bones were from a dinosaur by their similarity to those of Iguanodon, discovered in England some decades before, but at the time, the skeleton of Hadrosaurus was one of the most complete dinosaur skeletons known.
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Norman explained this by Owen's excessive workload in this period, including several administrative functions, polemics with fellow-scientists and the study of a large number of even more interesting newly discovered extinct animals, such as Archaeopteryx.Norman, D.B., 2000, "Professor Richard Owen and the important but neglected dinosaur Scelidosaurus harrisonii", Historical Biology, 14: 235–253 Norman also pointed out that Owen in 1861 suggested a lifestyle for Scelidosaurus that is very different from present ideas: it would have been a fish-eater and partially sea-dwelling. BMNH 39496, the first lectotype of Scelidosaurus, that proved to be a theropod instead. Owen had not indicated a holotype. In 1888, Richard Lydekker while cataloguing the BMNH fossils, designated some of the hindlimb fragments described in 1861, specimen BMNH 39496 consisting of a lower part of a femur and an upper part of the tibia and fibula, together forming a knee joint, as the type specimen, hereby implicitly choosing them as the lectotype of Scelidosaurus.
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Skeletal diagram showing the known remains of all three of the known specimens of Guaibasaurus candelariensis Guaibasaurus was originally named on the basis of the holotype, MCN PV2355, a well-preserved partial postcranial skeleton and the paratype, MCN PV2356, an articulated and nearly complete left hindlimb, which were discovered in the "Sesmaria do Pinhal 2" locality near Candelária, Rio Grande do Sul, in Brazil, in the upper portion of the Candelária Sequence or the Caturrita Formation. Later, two additional specimens were referred to G. candelariensis: UFRGS PV0725T (an articulated and nearly complete postcranial skeleton missing one forelimb, both feet and the neck), and MCN PV 10112 (a not-fully-prepared block containing articulated parts and some isolated elements, including a partial hand). The referred materials were collected from the "Linha São Luiz" locality near the town of Faxinal do Soturno, Rio Grande do Sul, also in the upper portion of the Candelária Sequence or the Caturrita Formation. All specimen were collected in these two localities from the lower portion of the Caturrita Formation (Rosário do Sul Group, Paraná Basin) or alternatively the uppermost Santa Maria 2 Sequence, dating to the early Norian faunal stage of the Late Triassic.
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Combined, the specimens provided relatively complete data on this group; they were united by their opisthopubic pelvis, slender mandible, and the toothless front of their jaws. Barsbold and Perle stated that though some of their features resembled those of ornithischians and sauropods, these similarities were superficial, and were distinct when examined in detail. While they were essentially different from other theropods (perhaps due to diverging from them relatively early), and therefore warranted a new infraorder, they did show similarities with them. Since the Erlikosaurus specimen lacked a pelvis, the authors were unsure if that of the undetermined segnosaurian could belong to it, in which case they would consider it part of a separate family. Though Erlikosaurus was difficult to compare directly to Segnosaurus due to the incompleteness of their remains, Perle stated in 1981 that there was no justification for separating it into another family. Reconstructed pelvis and metatarsus of the holotype of Segnosaurus, which together with Erlikosaurus became the basis of the new infraorder Segnosauria; this group is now a synonym of Therizinosauria In 1982, Perle reported hindlimb fragments similar to those of Segnosaurus, and assigned them to Therizinosaurus, whose forelimbs had been found in almost the same location.
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