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Pozycja filogenetyczna owiraptorozaurow /Dinozsauria: Theropoda/

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Osmolska H., Wolsan M., Maryanska T.

Działalność Naukowa PAN. Wybrane Zagadnienia

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2002

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tom 13

51-52

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Oviraptorosaur tail forms and functions

72%

Persons,IV W. S., Currie P. J., Norell M. A.

Acta Palaeontologica Polonica

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2014

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tom 59

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nr 3

Oviraptorosaur caudal osteology is unique among theropods and is characterized by posteriorly persistent and exceptionally wide transverse processes, anteroposteriorly short centra, and a high degree of flexibility across the pre-pygostyle vertebral series. Three-dimensional digital muscle reconstructions reveal that, while oviraptorosaur tails were reduced in length relative to the tails of other theropods, they were muscularly robust. Despite overall caudal length reduction, the relative size of the M. caudofemoralis in most oviraptorosaurs was comparable with those of other non-avian theropods. The discovery of a second Nomingia specimen with a pygostyle confirms that the fused terminal vertebrae of the type specimen were not an abnormality. New evidence shows that pygostyles were also present in the oviraptorosaurs Citipati and Conchoraptor. Based on the observed osteological morphology and inferred muscle morphology, along with the recognition that many members of the group probably sported broad tail-feather fans, it is postulated that oviraptorosaur tails were uniquely adapted to serve as dynamic intraspecific display structures. Similarities, including a reduced vertebral series and a terminal pygostyle, between the tails of oviraptorosaurs and the tails of theropods widely accepted as basal members of the Avialae, appear to be convergences.

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Why tyrannosaurid forelimbs were so short: An integrative hypothesis

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Padian K.

Acta Palaeontologica Polonica

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2022

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tom 67

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nr 1

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

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

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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.

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Head and neck posture in sauropod dinosaurs inferred from extant animals

72%

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.

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New sauropod trackways from the Middle Jurassic of Portugal

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Santos V. F., Moratalla J. J., Royo-Torres R.

Acta Palaeontologica Polonica

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2009

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tom 54

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nr 3

409-422

The Galinha tracksite reveals a sequence of Bajocian–Bathonian limestones belonging to the Serra de Aire Formation (West−Central Portugal) and is one of the few sites in the world where Middle Jurassic sauropod dinosaur tracks can be found. This tracksite is characterised by the presence of long, wide gauge sauropod trackways, the Middle Jurassic age of which suggests these dinosaurs were more widely distributed over time than previously thought. Two trackways contain unique pes and manus prints with morphologies that allow a new sauropod ichnotaxon to be described: Polyonyx gomesi igen. et isp. nov. On the basis of different manus/pes prints and trackway features, the proposal is made to subdivide Sauropodomorpha ichno−morphotypes into five groups: Tetrasauropus−like, Otozoum−like, Breviparopus/Parabrontopodus−like; Brontopodus−like, and Polyonyx−like. Polyonyx gomesi igen. et isp. nov. is thought to represent a nonneosauropod eusauropod, with a well developed manus digit I. The posterior orientation of this digit print suggests they were made by a eusauropod dinosaur with a posteriorly rotated pollex. The manus print morphologies observed in two trackways suggest a stage of manus structure intermediate between the primitive non−tubular sauropod manus and the tubular metacarpal arrangement characteristic of more derived sauropods. The low heteropody (manus:pes area ratio 1:2) of the trackway renders it possible they could have been made by eusauropods such as Turiasaurus riodevensis, which has a similar manus:pes area ratio. The Polyonyx igen. nov. trackway was made by non−neosauropod eusauropod, and suggests that wide gauge sauropod trackways were not exclusively made by Titanosauriformes.

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Mud-trapped herd captures evidence of distinctive dinosaur sociality

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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.

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New specimens of the crested theropod dinosaur Elmisaurus rarus from Mongolia

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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.

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A large predatory archosaur from the Late Triassic of Poland

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Niedzwiedzki G., Sulej T., Dzik J.

Acta Palaeontologica Polonica

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2012

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tom 57

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nr 2

We describe a new large predatory archosaur, Smok wawelski gen. et sp. nov., from the latest Triassic (latest Norian–early Rhaetian; approximately 205–200 Ma) of Lisowice (Lipie Śląskie clay−pit) in southern Poland. The length of the reconstructed skeleton is 5–6 m and that of the skull 50–60 cm, making S. wawelski larger than any other known predatory archosaur from the Late Triassic and Early Jurassic of central Europe (including theropod dinosaurs and “rauisuchian” crurotarsans). The holotype braincase is associated with skull, pelvic and isolated limb−bones found in close proximity (within 30 m), and we regard them as belonging to the same individual. Large, apparently tridactyl tracks that occur in the same rock unit may have been left by animals of the same species. The highly autapomorphic braincase shows large attachment areas for hypertrophied protractor pterygoideus muscles on the lateral surface and a wide, funnel−like region between the basal tubera and basipterygoid processes on the ventral surface. The skeleton (cranial and postcranial) possesses some features similar to those in theropod dinosaurs and others to those in large crocodile−line archosaurs (“rauisuchians”), rendering phylogenetic placement of S. wawelski difficult at this time.

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New evidence on brain-endocranial cavity relationships in ornithischian dinosaurs

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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.

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

72%

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.

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First Cenomanian dinosaur from Central Europe [Czech Republic]

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Fejfar O., Kostak M., Kvacek J., Mazuch M., Moucka M.

Acta Palaeontologica Polonica

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2005

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tom 50

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nr 2

We describe the first dinosaur skeletal remains found in the Czech Republic, consisting of one complete femur and indeterminable bone fragments. They were recovered from the upper Cenomanian near−shore marine sediments deposited on the slopes of an ancient archipelago, several kilometres north of the larger Rhenish−Bohemian Island that was situated in what is now the middle of Europe. Sediments yielding dinosaur remains are of late Cenomanian age, Inoceramus pictus–I. pictus bohemicusinoceramid zone of the local lithostratigraphic unit, the Peruc−Korycany Formation. These are the first uncontested dinosaurian fossils reported from this formation and also the first Cenomanian dinosaur record in Central Europe. They document a small ornithopod belonging to an iguanodontid species comparable with similar Late Cretaceous European forms. The herbivorous dinosaur lived among a vegetation transitional between salt marsh flora, with abundant halophytic conifer Frenelopsis alata; and an alluvial plain assemblage dominated by lauroid angiosperms.

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Avialan status for Oviraptorosauria

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Maryanska T., Osmolska H., Wolsan M.

Acta Palaeontologica Polonica

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2002

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tom 47

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nr 1

Oviraptorosauria is a clade of Cretaceous theropod dinosaurs of uncertain affinities within Maniraptoriformes. All previous phylogenetic analyses placed oviraptorosaurs outside a close relationship to birds (Avialae), recognizing Dromaeosauridae or Troodontidae, or a clade containing these two taxa (Deinonychosauria), as sister taxon to birds. Here we present the results of a phylogenetic analysis using 195 characters scored for four outgroup and 13 maniraptoriform (ingroup) terminal taxa, including new data on oviraptorids. This analysis places Oviraptorosauria within Avialae, in a sister−group relationship with Confuciusornis. Archaeopteryx, Therizinosauria, Dromaeosauridae, and Ornithomimosauria are successively more distant outgroups to the Confuciusornis−oviraptorosaur clade. Avimimus and Caudipteryx are successively more closely related to Oviraptoroidea, which contains the sister taxa Caenagnathidae and Oviraptoridae. Within Oviraptoridae, “Oviraptor” mongoliensis and Oviraptor philoceratops are successively more closely related to the Conchoraptor−Ingenia clade. Oviraptorosaurs are hypothesized to be secondarily flightless. Emended phylogenetic definitions are provided for Oviraptoridae, Caenagnathidae, Oviraptoroidea, Oviraptorosauria, Avialae, Eumaniraptora, Maniraptora, and Maniraptoriformes.

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Caudipteryx as a non-avalian theropod rather than a flightless bird

72%

Dyke G. J., Norell M. A.

Acta Palaeontologica Polonica

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2005

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tom 50

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nr 1

Caudipteryx zoui is a small enigmatic theropod known from the Early Cretaceous Yixian Formation of the People’s Republic of China. From the time of its initial description, this taxon has stimulated a great deal of ongoing debate regarding the phylogenetic relationship between non−avialan theropods and birds (Avialae) because it preserves structures that have been uncontroversially accepted as feathers (albeit aerodynamically unsuitable for flight). However, it has also been proposed that both the relative proportions of the hind limb bones (when compared with overall leg length), and the position of the center of mass in Caudipteryx are more similar to those seen in extant cusorial birds than they are to other non−avialan theropod dinosaurs. This conclusion has been used to imply that Caudipteryx may not have been correctly interpreted as a feathered non−avialan theropod, but instead that this taxon represents some kind of flightless bird. We review the evidence for this claim at the level of both the included fossil specimen data, and in terms of the validity of the results presented. There is no reason—phylogenetic, morphometric or otherwise—to conclude that Caudipteryx is anything other than a small non−avialan theropod dinosaur.

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The lambeosaurine dinosaur Amurosaurus riabinini, from the Maastrichtian of Far Eastern Russia

72%

Godefroit P., Bolotsky Y. L., Van Itterbeeck J.

Acta Palaeontologica Polonica

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2004

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tom 49

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nr 4

Amurosaurus riabinini Bolotsky and Kurzanov, 1991 (Dinosauria, Hadrosauridae) is described on the basis of numerous disarticulated bones from the Maastrichtian Udurchukan Formation of Blagoveschensk, Far Eastern Russia. Comparisons with North American palynozones and their well−calibrated ages suggest that this formation is late Maastrichtian in age. It is shown that A. riabinini is a valid species, characterised by cranial and postcranial autapomorphies. A phylogenetic analysis, based on 40 cranial, dental, and postcranial characters, indicates that this taxon occupies a relatively basal position within the lambeosaurine subfamily as the sister−taxon of a monophyletic group formed by the parasauroloph and corythosaur clades. This cladogram also demonstrates that lambeosaurines have an Asian origin. In eastern Asia, lambeosaurine dinosaurs dominate late Maastrichtian dinosaur localities, whereas this group is apparently no longer represented in synchronous localities from western North America.

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An ankylosaurid dinosaur from Mongolia with in situ armour and keratinous scale impressions

58%

Arbour V. M., Lech-Hernes N. L., Guldberg T. E., Hurum J. H., Currie P. J.

Acta Palaeontologica Polonica

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2013

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tom 58

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nr 1

A Mongolian ankylosaurid specimen identified as Tarchia gigantea is an articulated skeleton including dorsal ribs, the sacrum, a nearly complete caudal series, and in situ osteoderms. The tail is the longest complete tail of any known ankylosaurid. Remarkably, the specimen is also the first Mongolian ankylosaurid that preserves impressions of the keratinous scales overlying the bony osteoderms. This specimen provides new information on the shape, texture, and ar− rangement of osteoderms. Large flat, keeled osteoderms are found over the pelvis, and osteoderms along the tail include large keeled osteoderms, elongate osteoderms lacking distinct apices, and medium−sized, oval osteoderms. The specimen differs in some respects from other Tarchia gigantea specimens, including the morphology of the neural spines of the tail club handle and several of the largest osteoderms.

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Osteology of the Late Cretaceous alvarezsauroid Linhenykus monodactylus from China and comments on alvarezsauroid biogeography

58%

Xu X., Upchurch P., Ma Q., Pittman M., Choiniere J., Sullivan C., Hone D. W. E., Tan Q., Tan L., Xiao D., Han F.

Acta Palaeontologica Polonica

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2013

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tom 58

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nr 1

The alvarezsauroid theropod Linhenykus monodactylus from the Upper Cretaceous of Inner Mongolia, China is the first knownmonodactyl non−avian dinosaur, providing important information on the complex patterns of manual evolution seen in alvarezsauroids. Herewe provide a detailed description of the osteology of this taxon. Linhenykus shows a number of fea− tures that are transitional between parvicursorine and non−parvicursorine alvarezsauroids, but detailed comparisons also re− veal that some characters had a more complex distribution. We also use event−based tree−fitting to perform a quantitative analysis of alvarezsauroid biogeography incorporating several recently discovered taxa. The results suggest that there is no statistical support for previous biogeographic hypotheses that favour pure vicariance or pure dispersal scenarios as explana− tions for the distributions of alvarezsauroids across SouthAmerica, NorthAmerica andAsia. Instead, statistically significant biogeographic reconstructions suggest a dominant role for sympatric (or “within area”) events, combined with a mix of vicariance, dispersal and regional extinction. At present the alvarezsauroid data set is too small to completely resolve the biogeographic history of this group: future studies will need to create larger data sets that encompass additional clades.

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Upper Cretaceous amniotic eggs from Gobi Desert

58%

Sabath K.

Acta Palaeontologica Polonica

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1991

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tom 36

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nr 2

There are described several types of Upper Cretaceous fossil amniote eggs, clutches and eggshells, collected during the Polish-Mongolian Paleontological Expeditions (1963—1971) in several localities of the Gobi Desert. Isotopic ratios of C and О are reported and discussed. The eggs may be attributed to saurischian and ornithischian dinosaurs, and palaeognathous birds. Four types of problematica are also described. Taphonomy and restoration of eggshells’ diffusive properties as compared with modern hard-shelled eggs suggest paleoecological interpretation of the nesting conditions as rather dry for smooth-shelled eggs, humid for ornamented eggs, and very humid for the thickest-shelled eggs. Different nest types are postulated for ornamented and smooth eggs, based on taphonomy and shell parameters.

20

New material of a derived ornithomimosaur from the Upper Cretaceous Nemegt Formation of Mongolia

58%

Bronowicz R.

Acta Palaeontologica Polonica

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2011

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tom 56

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nr 3

New material of an ornithomimid from the Late Cretaceous deposits of Tsagan Khushu (Gobi Desert, Mongolia) is described. The material includes a partial axial skeleton, and hind and forelimb elements. The specimen is similar to Anserimimus planinychus from nearby Bugin Tsav locality in having ventrally flat, long, almost straight manual unguals. The new specimen differs from A. planinychus in the length of the penultimate manual phalanx II−2, which is only slightly shorter than Ph III−3, in a considerably lesser alae of the manual unguals, and in the height/width ratio of the proximal articular surfaces. The material suggests presence of third, hitherto unknown ornithomimid from the Nemegt Formation.

Ograniczanie wyników

Pozycja filogenetyczna owiraptorozaurow /Dinozsauria: Theropoda/

Oviraptorosaur tail forms and functions

Why tyrannosaurid forelimbs were so short: An integrative hypothesis

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

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

Head and neck posture in sauropod dinosaurs inferred from extant animals

New sauropod trackways from the Middle Jurassic of Portugal

Mud-trapped herd captures evidence of distinctive dinosaur sociality

New specimens of the crested theropod dinosaur Elmisaurus rarus from Mongolia

A large predatory archosaur from the Late Triassic of Poland

New evidence on brain-endocranial cavity relationships in ornithischian dinosaurs

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

First Cenomanian dinosaur from Central Europe [Czech Republic]

Avialan status for Oviraptorosauria

Caudipteryx as a non-avalian theropod rather than a flightless bird

The lambeosaurine dinosaur Amurosaurus riabinini, from the Maastrichtian of Far Eastern Russia

An ankylosaurid dinosaur from Mongolia with in situ armour and keratinous scale impressions

Osteology of the Late Cretaceous alvarezsauroid Linhenykus monodactylus from China and comments on alvarezsauroid biogeography

Upper Cretaceous amniotic eggs from Gobi Desert

New material of a derived ornithomimosaur from the Upper Cretaceous Nemegt Formation of Mongolia