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Preservation of Arctic dinosaur remains from the Prince Creek Formation (Alaska, USA): A reply to Fiorillo (2016)

100%

Mori H., Druckenmiller P. S., Erickson G. M.

Acta Palaeontologica Polonica

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2016

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tom 61

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nr 1

2

Karol Sabath (1963–2007)

100%

Kielan-Jaworowska Z.

Acta Palaeontologica Polonica

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2007

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tom 52

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nr 4

3

Gastroliths in an ornithopod dinosaur

100%

Cerda I. A.

Acta Palaeontologica Polonica

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2008

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tom 53

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nr 2

Gastroliths (stomach stones) are known from many extant and extinct vertebrates, including dinosaurs. Reported here is the first unambiguous record of gastroliths in an ornithopod dinosaur. Clusters of small stones found in the abdominal region of three articulated skeletons of Gasparinisaura cincosaltensis were identified as gastroliths on the basis of taphonomic and sedimentologic evidence. The large number of stones found in each individual, their size, and the fact that Gasparinisaura cincosaltensis was herbivorous, all suggest that they were ingested as a result of lithophagy rather than accidental swallowing.

4

Speeds of dinosaurs from the Albian-Cenomanian of Patagonia and sauropod stance and gait

100%

Mazzetta G. V., Blanco R. E.

Acta Palaeontologica Polonica

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2001

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tom 46

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nr 2

Estimates of locomotory speeds of small to large-sized Patagonian dinosaurs are presented for the first time. These estimates are inferred from trackways found on fine to coarse-grained brown sandstones located in the lower section of the Candeleros Member of the Río Limay Formation (Albian-Cenomanian), Neuquén Province, Argentina. The method used is based on the measurement of the stride length (distance between two successive prints of the same foot) and of the length of the hindfoot print, which in turn, allows us to estimate the height at the hip joint and, therefore, the approximate size of the animal. The hypothesis of dynamic similarity implies that the movements of geometrically similar animals, although of different sizes, are dynamically similar only when they move with the same Froude number. The dynamically similar movements (i.e., those with equal Froude number) require equal values of relative stride length (ratio between the stride length and the hip joint height). The relationship between the relative stride length and the Froude number allows us to estimate the speeds of dinosaurs. The dinosaurian ichnofauna studied reveals low speeds that range from 0.5 to 2.6 m s⁻¹. Our analyses show that the sauropods responsible for these trackways were either walking very slowly in a bipedal stance or alternatively they were progressing quadrupedally on a slippery surface.

5

Halszka Osmolska [1930-2008]

100%

Borsuk-Bialynicka M., Maryanska T.

Acta Palaeontologica Polonica

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2008

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tom 53

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nr 2

6

Evidence on relation of brain to endocranial cavity in oviraptorid dinosaurs

100%

Osmolska H.

Acta Palaeontologica Polonica

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2004

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tom 49

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nr 2

Brains in living tetrapods other than birds and mammals do not entirely fill the brain cavities. Examination of dinosaur braincases does not usually allow determination relating to how close walls of endocranial cavity lay to the surface of brain. The here described fragment of a skull roof of an oviraptorid dinosaur, Ingenia yanshini, shows perfectly preserved, numerous vascular imprints that cover the internal surfaces of frontals and parietals in the region roofing the cerebral hemispheres and cerebellum. This specimen shows that in oviraptorids the brain closely fitted the brain cavity, to the extent found in birds and mammals. Among dinosaurs, only one similar case has been previously reported in an ornithomimid, Dromiceiomimus brevitertius, but the preserved vascular imprints are less numerous and regular in this dinosaur than in Ingenia yanshini.

7

First record of a basal neoceratopsian dinosaur from the Late Cretaceous of Kazakhstan

84%

Averianov A., Sues H. D.

Acta Palaeontologica Polonica

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2009

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tom 54

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nr 3

553-556

The oldest known ceratopsians come from the Late Jurassic of China (Zhao et al. 1999; Xu et al. 2006). During the Early Cretaceous, the basal ceratopsian Psittacosaurus was among the most common dinosaurs in Asia but more derived basal neoceratopsians were quite rare on that continent (Xu et al. 2002; Makovicky and Norell 2006). Basal neoceratopsians became more abundant in the Late Cretaceous of Mongolia and China, although they are not known in this region from the latest Cretaceous (You and Dodson 2004; Alifanov 2008). In contrast, basal neoceratopsians are rare during the Early Cretaceous in North America but became common and diverse during the Campanian and Maastrichtian (You and Dodson 2004; Chinnery and Horner 2007). Little is known about the evolutionary history of this group in more inland regions of what are now Kazakhstan and adjoining countries. Asiaceratops documents the presence of basal neoceratopsians in the Cenomanian of Uzbekistan (Nessov et al. 1989). Here we report on the first record of a basal neoceratopsian in the Late Cretaceous of Kazakhstan, based on two cranial bones from the Turonian Zhirkindek Formation in the northeastern Aral Sea region.

8

A monument of inefficiency: The presumed course of the recurrent laryngeal nerve in sauropod dinosaurs

84%

Wedel M. J.

Acta Palaeontologica Polonica

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2012

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tom 57

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nr 2

The recurrent laryngeal nerve is an often cited example of “unintelligent design” in biology, especially in the giraffe. The nerve appears early in embryonic development, before the pharyngeal and aortic arches are separated by the development of the neck. The recurrent course of the nerve from the brain, around the great vessels, to the larynx, is shared by all extant tetrapods. Therefore we may infer that the recurrent laryngeal nerve was present in extinct tetrapods, had the same developmental origin, and followed the same course. The longest−necked animals of all time were the extinct sauropod dinosaurs, some of which had necks 14 meters long. In these animals, the neurons that comprised the recurrent laryngeal nerve were at least 28 meters long. Still longer neurons may have spanned the distance from the end of the tail to the brainstem, as in all extant vertebrates. In the longest sauropods these neurons may have been 40–50 meters long, probably the longest cells in the history of life.

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The early evolution of postcranial skeletal pneumaticity in sauropodomorph dinosaurs

84%

Yates A. M., Wedel M. J., Bonnan M. F.

Acta Palaeontologica Polonica

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2012

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tom 57

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nr 1

Postcranial skeletal pneumaticity (PSP) is present in a range of basal sauropodomorphs spanning the basal sauropodomorph–sauropod transition. We describe the PSP of five taxa, Plateosaurus engelhardti, Eucnemesaurus fortis, Aardonyx celestae, Antetonitrus ingenipes, and an unnamed basal sauropod from Spion Kop, South Africa (hereafter referred to as the Spion Kop sauropod). The PSP of Plateosaurus is apparently sporadic in its occurrence and has only been observed in very few specimens, in which it is of very limited extent, affecting only the posterior cervical vertebrae and possibly the mid dorsals in one specimen. The PSP of Eucnemesaurus, Aardonyx, Antetonitrus, and the Spion Kop sauropod consists of subfossae (fossa−within−fossa structures) that excavate the vertices of the posterior infradiapophyseal fossae of the posterior dorsal vertebrae. These subfossae range from simple shallow depressions (Eucnemesaurus) to deep, steepsided, internally subdivided and asymmetrically developed chambers (Antetonitrus). The middle and anterior dorsal vertebrae of these taxa lack PSP, demonstrating that abdominal air sacs were the source of the invasive diverticula. The presence of pneumatic features within the infradiapophyseal fossae suggest that the homologous fossae of more basal saurischians and dinosauriforms were receptacles that housed pneumatic diverticula. We suggest that it is probable that rigid non−compliant lungs ventilated by compliant posterior air sacs evolved prior to the origination of Dinosauria.

10

An articulated pes from a small parvicursorine alvarezsauroid dinosaur from Inner Mongolia, China

84%

Hone D. W. E., Choiniere J. N., Tan Q., Xu X.

Acta Palaeontologica Polonica

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2013

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tom 58

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nr 3

A near complete and articulated parvicursorine pes from the Campanian Wulansuhai Formation is described. This pes is referred to the genus Linhenykus and is one of the first foot skeletons to be described for a derived alvarezsaur, providing new information on the first digit of the pes. The evolution of a laterally directed flange of the anterior face of the distal third metatarsal in arctometatarsalian taxa is described and discussed. This flange may have increased stability of the foot during cursorial locomotion and may also provide useful taxonomic and systematic data.

11

Evidence for a sauropod-like metacarpal configuration in ankylosaurian dinosaurs

84%

Senter P.

Acta Palaeontologica Polonica

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2011

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tom 56

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nr 1

Ankylosaurian dinosaurs are armored, quadrupedal members of the ornithischian clade Thyreophora. Ankylosaurs are typically portrayed with the metacarpals slanted and distally divergent, with their proximal ends arranged in a shallow arc, both in the literature (Matthew 1922; Gaston et al. 2001; McCrea et al. 2001; Vickaryous et al. 2004) and in museum mounts (Fig. 1). In contrast, Carpenter (1984) illustrated the metacarpals of the ankylosaur Sauropelta edwardsorum Ostrom, 1970, from the Lower Cretaceous Cloverly Formation of Wyoming and Montana, with their proximal ends arranged in a tight, semicircular arc, but even in that depiction the metacarpals were slanted and distally divergent. Members of the thyreophoran clade Stegosauria, the sister taxon to the Ankylosauria (Butler et al. 2008), have also typically been portrayed with slanted and distally divergent metacarpals (Marsh 1891; Gilmore 1914; Galton and Upchurch 2004). Some researchers expressed the opinion that stegosaur metacarpals were held vertically, not distally divergent, with their proximal ends arranged in a tight, semicircular arc, so that the metacarpus formed a vertical half−tube (von Huene 1931; Thulborn 1990; Christiansen 1997) such that flexion of digit I would move it toward digit V. Manual manipulation of stegosaurian metacarpals has since confirmed that this is the correct configuration of the stegosaurian metacarpus (Senter 2010). Here I investigate the possibility that the ankylosaurian metacarpus exhibited a similar configuration. As in the previous study on stegosaurs (Senter 2010), I treat the slanting and spreading configuration and the vertical semi−tubular configuration as competing hypotheses, each with a set of testable predictions. Each hypothesis of metacarpal configuration in ankylosaurs predicts that the configuration (1) is allowed by the shapes of the metacarpals, (2) provides a better fit (alignment and contact of opposing articular surfaces) between the metacarpals than the competing hypothesis, (3) does not compromise the goodness of fit between the metacarpals and the phalanges, (4) is not contradicted by articulated specimens, and (5) agrees with ichnological evidence. In the previous study on stegosaurs I included an additional prediction: that the configuration provides sufficient support for and does not disarticulate the more proximal forelimb bones. Here, that prediction is omitted, because the ankylosaurian carpus is unknown (Vickaryous et al. 2004) except for a single carpal described by Maleev (1954).

12

A Lujiatun-like dinosaurian assemblage from the Jehol Biota of Ningcheng, Inner Mongolia, Northeast China

84%

Zhang H., Yu D., Feng Y., Pei R., Zhou C.-F.

Acta Palaeontologica Polonica

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2022

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tom 67

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nr 3

13

Head and neck posture in sauropod dinosaurs inferred from extant animals

84%

Taylor M. P., Wedel M. J., Naish D.

Acta Palaeontologica Polonica

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2009

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tom 54

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nr 2

213-220

The neck posture of sauropod dinosaurs has long been controversial. Recent reconstructions position the cervical vertebrae and skull in an “osteological neutral pose” (ONP), the best fit arrived at by articulating the vertebrae with the zygapophyses in maximum contact. This approach in isolation suggests that most or all sauropods held their necks horizontally. However, a substantial literature on extant amniotes (mammals, turtles, squamates, crocodilians and birds) shows that living animals do not habitually maintain their necks in ONP. Instead, the neck is maximally extended and the head is maximally flexed, so that the mid−cervical region is near vertical. Unless sauropods behaved differently from all extant amniote groups, they must have habitually held their necks extended and their heads flexed. The life orientation of the heads of sauropods has been inferred from the inclination of the semi−circular canals. However, extant animals show wide variation in inclination of the “horizontal” semi−circular canal: the orientation of this structure is not tightly constrained and can give only a general idea of the life posture of extinct animals’ heads.

14

Mud-trapped herd captures evidence of distinctive dinosaur sociality

84%

Varricchio D. J., Sereno P. C., Xijin Z., Lin T., Wilson J. A., Lyon G. H.

Acta Palaeontologica Polonica

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2008

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tom 53

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nr 4

A unique dinosaur assemblage from the Cretaceous beds of western Inner Mongolia preserves geologic and paleontologic data that clearly delineate both the timing and mechanism of death. Over twenty individuals of the ornithomimid Sinornithomimus dongi perished while trapped in the mud of a drying lake or pond, the proximity and alignment of the mired skeletons indicating a catastrophic mass mortality of a social group. Histologic examination reveals the group to consist entirely of immature individuals between one and seven years of age, with no hatchlings or mature individuals. The Sinornithomimus locality supports the interpretation of other, more taphonomically ambiguous assemblages of immature dinosaurs as reflective of juvenile sociality. Adults of various nonavian dinosaurs are known to have engaged in prolonged nesting and post hatching parental care, a life history strategy that implies juveniles spent considerable time away from reproductively active adults. Herding of juveniles, here documented in a Cretaceous ornithomimid, may have been a common life history strategy among nonavian dinosaurs reflecting their oviparity, extensive parental care, and multi−year maturation.

15

New specimens of the crested theropod dinosaur Elmisaurus rarus from Mongolia

84%

Currie P. J., Funston G. F., Osmolska H.

Acta Palaeontologica Polonica

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2016

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tom 61

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nr 1

New specimens of Elmisaurus rarus from the Upper Cretaceous of Mongolia (Nemegt Formation) preserve bones not previously found in “elmisaurids” that help elucidate their relationships to Leptorhynchos elegans and other oviraptorosaurs. Elmisaurus rarus and the North American Leptorhynchos elegans are known from numerous but incomplete specimens that are closely related to, but nevertheless clearly distinguished from, Chirostenotes pergracilis and Epichirostenotes curriei. These specimens include the first known cranial bone attributed to Elmisaurus, the frontal, which clearly shows this animal had a cranial crest (most of which would have been formed by the nasal bones). The first vertebrae, scapula, femora, and tibiae from Elmisaurus are also described. The Elmisaurinae can be distinguished from the Caenagnathinae by the coossification of the tarsometatarsus and smaller size at maturity. Examination of oviraptorosaur hindlimbs reveals four distinct morphotypes, possibly attributable to paleoecological differences.

16

The endocranial morphology and inner ear of the abelisaurid theropod Aucasaurus garridoi

84%

Paulina-Carabajal A., Succar C.

Acta Palaeontologica Polonica

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2015

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tom 60

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nr 1

A partial cranial endocast and right inner ear of the Cretaceous abelisaurid dinosaur Aucasaurus garridoi were digitally reconstructed from CT scans. The forebrain, midbrain, and hindbrain resemble the morphology described for the abelisaurids Majungasaurus and Indosaurus. However, Aucasaurus exhibits a floccular process that is relatively larger than that of Majungasaurus. In Aucasaurus the flocculus is enclosed in an 8-shaped floccular recess, similar in shape and size to that observed in Abelisaurus, suggesting that the two Patagonian taxa were capable of a slightly wider range of movements of the head. Here we describe the second inner ear known for the Abelisauridae. The labyrinth of the inner ear is similar in shape and size to the semicircular canals of Majungasaurus, although the lateral semicircular canal is shorter in Aucasaurus.

17

New evidence on brain-endocranial cavity relationships in ornithischian dinosaurs

84%

Evans D. C.

Acta Palaeontologica Polonica

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2005

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tom 50

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nr 3

Discussions of brain morphology and relative brain size in nonavian dinosaurs have been complicated by uncertainty in the extent to which the brain filled the endocranial cavity. Recently reported vascular imprints (valleculae) on the endocranial surfaces of the braincase suggest that nonavian maniraptoriform theropods had brains that tightly fit the endocranium. Similar impressions of the intracranial vascular system are reported here in two ornithischian clades, Hadrosauridae and Pachycephalosauridae. These structures are more widespread in dinosaurs than previously thought, and suggest that the brain closely fit the endocranium in some regions of the forebrain through hindbrain in several distantly related dinosaur groups.

18

The endocranium of the theropod dinosaur Ceratosaurus studied with computer tomography

84%

Sanders R. K., Smith D. K.

Acta Palaeontologica Polonica

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2005

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tom 50

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nr 3

A well preserved specimen of the theropod Ceratosaurusfrom the Upper Jurassic Morrison Formation of western Colorado was recently described and given the name C. magnicornis. The systematics of the genus is outside the scope of the present study but, as a generally accepted basal tetanuran, the braincase was CT scanned to provide a description of the endocranium, inner ear, pneumatic, and venous sinus systems in a primitive member of this clade. Five major subregions of the theropod endocranium are distinguished for the purpose of simplifying cranial computed tomographic interpretation and to provide a systematic means of comparison to other endocrania. The skull morphology of Ceratosaurus influences the overall braincase morphology and the number and distribution of the major foramina. The low pontine angle and relatively unflexed braincase is considered a more primitive character. The orientation of the horizontal semicircular canal confirms a rather horizontal and unerect posture of the head and neck. As in birds, the narrower skull morphology of Ceratosaurusis associated with fewer cranial nerve foramina. Additionally, the maxillary dominated dentigerous upper jaw of Ceratosaurusis felt to share with the alligator a large rostrally directed maxillary division of the trigeminal nerve and a small ophthalmic branch. The upper bill of birds, being dominated by the premaxillary and lacking teeth, is innervated predominantly by the ophthalmic division of the trigeminal nerve. For this reason, avian−based cranial nerve reconstructions are felt to be inappropriate for basal theropods.Ceratosaurusskull pneumatization and possible evidence of olfactory conchal structures is on the other hand very avian in character. Based on computed tomography, Ceratosaurusis determined to have possessed a typical basal theropod endocranium and bipedal vestibular system similar to Allosaurus.

19

The dinosaur Hadrosaurus foulkii, from the Campanian of the East Coast of North America, with a reevaluation of the genus

84%

Prieto-Marquez A., Weishampel D. B., Horner J. R.

Acta Palaeontologica Polonica

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2006

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tom 51

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nr 1

Hadrosaurus foulkii was the first dinosaur known outside Europe from partially complete skeletal elements. It is the holotype of the family Hadrosauridae and the subfamily Hadrosaurinae. The history of its discovery and taxonomy is reviewed, and the holotype of H. foulkii is redescribed. The holotype of H. foulkii lacks distinguishing characters; therefore, this taxon is a nomen dubium. It is not synonymous with species of Gryposaurus and/or Kritosaurus. We also reevaluate the taxonomy and osteology of H. tripos, H. minor, H. cavatus, H. breviceps, H. paucidens, and Ornithotarsus immanis. In agreement with previous studies, these taxa are considered nomina dubia due to the absence of distinguishing characters and are therefore referrable only to Hadrosauridae indeterminate; H. paucidensis referrable to Lambeosaurinae indeterminate. Finally, our phylogenetic analysis indicates that the holotype of H. foulkii belongs to a member of Euhadrosauria and, tentatively, of Hadrosaurinae.

20

A new approach to evaluate the cursorial ability of the giant theropod Giganotosaurus carolinii

84%

Blanco R. E., Mazzetta G. V.

Acta Palaeontologica Polonica

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2001

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tom 46

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nr 2

The cursorial capability of the South American giant theropod Giganotosaurus carolinii should have been quite limited taking into account the strength indicator of its femur (approximately 7 GPa⁻¹) as well as the risk of experiencing grave or even lethal injuries involved in the falling of this multitonne animal on a run. However, even at low speeds a fall would have caused serious injuries. Thus, in accordance to the approach developed in this study, the maximum speed of Giganotosaurus should be not that which will implicate corporal lesions with minimum probability of lethalness. Instead, its maximum speed should be that which would permit the recovery of body equilibrium as each step is taken. Taking into consideration this approach, an indicator of stability is defined for bipedal, cursorial animals. This indicator is determined by the relationship between the time available for the movement of hip joint during the retraction of a hindlimb and the time needed to move the opposite hindlimb by an angle (in function of the speed) of sufficient magnitude as to facilitate the recovery of body equilibrium. This indicator was used to estimate the maximum speed of locomotion of Giganotosaurus (about 14 m s⁻¹) at which, from a kinematic point of view, the danger of falling does not exist.

Ograniczanie wyników

Preservation of Arctic dinosaur remains from the Prince Creek Formation (Alaska, USA): A reply to Fiorillo (2016)

Karol Sabath (1963–2007)

Gastroliths in an ornithopod dinosaur

Speeds of dinosaurs from the Albian-Cenomanian of Patagonia and sauropod stance and gait

Halszka Osmolska [1930-2008]

Evidence on relation of brain to endocranial cavity in oviraptorid dinosaurs

First record of a basal neoceratopsian dinosaur from the Late Cretaceous of Kazakhstan

A monument of inefficiency: The presumed course of the recurrent laryngeal nerve in sauropod dinosaurs

The early evolution of postcranial skeletal pneumaticity in sauropodomorph dinosaurs

An articulated pes from a small parvicursorine alvarezsauroid dinosaur from Inner Mongolia, China

Evidence for a sauropod-like metacarpal configuration in ankylosaurian dinosaurs

A Lujiatun-like dinosaurian assemblage from the Jehol Biota of Ningcheng, Inner Mongolia, Northeast China

Head and neck posture in sauropod dinosaurs inferred from extant animals

Mud-trapped herd captures evidence of distinctive dinosaur sociality

New specimens of the crested theropod dinosaur Elmisaurus rarus from Mongolia

The endocranial morphology and inner ear of the abelisaurid theropod Aucasaurus garridoi

New evidence on brain-endocranial cavity relationships in ornithischian dinosaurs

The endocranium of the theropod dinosaur Ceratosaurus studied with computer tomography

The dinosaur Hadrosaurus foulkii, from the Campanian of the East Coast of North America, with a reevaluation of the genus

A new approach to evaluate the cursorial ability of the giant theropod Giganotosaurus carolinii