Dissertations / Theses on the topic 'Theropods'
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Rauhut, Oliver Walter Mischa. "The interrelationships and evolution of basal theropods (Dinosauria, Saurischia)." Thesis, University of Bristol, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.310688.
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Signore, Marco. "Scipionyx samniticus (Therpoda, maniraptoriformes) and the palaeobiology of some maniraptoran theropods." Thesis, University of Bristol, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.368643.
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Brusatte, Stephen L. "The skull of Monolophosaurus jingi (Dinosauria: Theropoda) and its implications for early theropod phylogeny and evolution." Thesis, University of Bristol, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.492554.
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The Middle Jurassic was a critical time in the evolution of theropod dinosaurs, highlighted by the origination and initial radiation of the large-bodied and morphologically diverse Tetanurae. Middle Jurassic tetanurans are rare but have been described from Europe, South America, and China. In particular, China has yielded a number of potential basal tetanurans but these have received little detailed treatment in the literature.
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Tahara, Rui. "Cranial pneumaticity of «Ornithomimus edmontonicus» (Ornithomimidae: Theropoda)." Thesis, McGill University, 2009. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=40806.
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Modern archosaurs have extensive pneumatic invasions derived from nasal and tympanic sinuses. These are present in many fossil archosaurs, but their evolutionary history has yet to be clarified. A full description of the cranial pneumaticity of a well-preserved ornithomimid theropod is presented to help clarify the evolution of this soft tissue using CT scan data and 3D reconstruction. The cranial sinuses of Ornithomimus edmontonicus represent nearly all cranial sinuses of birds and add new information to the range of that of ornithomimids. Phylogenetic comparisons of cranial pneumaticity across theropods with emphasis on O. edmontonicus imply a novel homology between the jugal fossa or recess of non-avian theropods and the suborbital diverticulum of birds. Comparisons also establish the presence of an avian-like nasal sinus morphology at Neotetanurae and tympanic sinus morphology at Coelurosauria.Les archosauriens modernes ont des invasions pneumatiques extensives dérivées de leurs sinus nasales et tympaniques. Ils sont présents dans de nombreux fossiles d’archosauriens, mais l’histoire de leur évolution demeure incertaine. Une description complète de la pneumaticité crâniens d’un théropode ornithomimidé bien préservé aide à clarifier l’évolution de ces tissues mous à l’aide de donnés d’un scanneur CT et de la reconstruction 3D. Les sinus crâniennes de Omithomimus edmontonicus représentent presque tous les sinus crâniens des oiseaux et rajoutent de nouvelles informations en ce qui à trait aux ornithomimidés. Les comparaisons phylogénétiques de la pneumaticité crânienne à travers les théropodes avec une emphase sur O. edmontonicus suggèrent une nouvelle homologie de la jugal fossa ou la dépression des théropodes non-aviaires et le diverticulum sous-orbital des oiseaux. Les comparaisons permettent aussi d’établir la présence de sinus nasals à morphologie aviaire au Neotetanurae et de sinus à morphologie tympanique au Coelurosauria.
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Silva, Rosely Rodrigues da. "Descrição osteológica e posicionamento filogenético de um terópode (Dinosauria, Saurischia) do Cretáceo Inferior da Bacia Sanfranciscana, município de Coração de Jesus, Minas Gerais, Brasil." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/41/41133/tde-22072013-110420/.
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A região do cráton São Francisco possui um histórico de eventos de sedimentações que datam do Paleo-Proterozóico e Mesozóico. A Bacia Sanfranciscana representa o último ciclo geodinâmico que afetou a grande Bacia Intracratônica do São Francisco. Embora o Cretáceo brasileiro seja considerado o período geológico mais bem representativo em termos de conteúdo de paleofauna de vertebrados, na Bacia Sanfranciscana este registro era restrito até recentemente apenas por celacantídeos e fragmentos de peixes do Grupo Areado. Através dos trabalhos de campos executados pela equipe do Laboratório de Paleontologia do Museu de Zoologia da USP, novos fósseis de tetrápodes continentais foram encontrados em sedimentos da Formação Quiricó, nos arredores do município de Coração de Jesus (MG). Dentre estes materiais, destacam-se elementos epipodiais, mesopodiais e metapodiais atribuíveis a um terópode. Este estudo visou descrever e comparar a osteologia do novo exemplar, tombado sob o número MZSP-PV 830, com outros registros de abelissauroideos conhecidos além de posicionar filogeneticamente com os outros táxons da irradiação de terópodes formada pelo clado Ceratosauria. Neste sentido, a análise da matriz de dados alocou-o no clado Noasauridae, com base nas seguintes características: a forma tabular do maléolo lateral da tíbia; e a forma estreita da haste do metatarsal II. A presente descrição representa uma relevância paleontológica significativa para o entendimento da diversificação dos terópodes no continente sul-americano. O material representa o primeiro registro osteológico de Noasauridae para o Brasil, o segundo representante de noassaurídeo de idade Aptiana, e é também a primeira descrição de um terópode para a região praticamente inexplorada da Bacia SanfranciscanaThe region of the São Francisco craton has a history of sedimentation events dating from the Paleo-Proterozoic and Mesozoic. Sanfranciscana Basin sedimentation represents the last geodynamic cycle that affected the large Sanfranciscana Intracratonic Basin. Despite the Cretaceous of Brazil being the best represented geological period in terms of vertebrate paleofauna, this kind of record in Sanfranciscana Basin was until recently restricted to coelacanths and fragments of fish from Areado Group. Through fieldwork performed by the Laboratory of Paleontology at the Museu de Zoologia - USP, new fossils of continental tetrapods were found in Formation Quiricó sediments, on the vicinity of the city of Coração de Jesus (MG). Among these materials, we highlight epipodials, mesopodials and metapodials elements attributable to a theropod. This study aimed to describe and compare the osteology of this new specimen, numbered as MZSP-PV 830, with other known abelisauroids and also allocate it phylogenetically among the other theropod taxa irradiation of Ceratosauria clade. In this sense, the analysis of the data matrix allocated the new taxon in the Noasauridae clade, based on the following characteristics: the tabular shape of the lateral malleolus of the tibia; and the narrow shape of the metatarsal II shaft. The present description represents a significant paleontological relevance for understanding the diversification of theropods in South America. This material represents the first osteological record of Noasauridae to Brazil, the second noasaurid representative from the Aptian age, as well is the first description of a theropod from the virtually unexplored region of the Sanfranciscana basin
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Ferreira, Rafael Delcourt de Seixas. "Evolução morfológica de Ceratosauria e Tyrannosauroidea (Dinosauria: Theropoda)." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/38/38131/tde-09122016-115432/.
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Theropoda foram os dinossauros mais bem sucedidos durante e Era Mesozoica e mantiveram-se bem diversos até os tempos presentes. Dentre eles, Tyrannosauroidea e Ceratosauria foram amplamente distribuídos entre os hemisférios norte e sul durante os Períodos Jurássico e Cretáceo, respectivamente. Ambos foram predadores de topo, com formas basais possuindo crânios pequenos, pescoços compridos, pernas e caudas alongadas; enquanto as formas mais derivadas eram caracterizadas com crânios maiores, pescoços curtos e membros anteriores e caudas reduzidas. Apesar de Tyrannosauroidea não ser próximo filogeneticamente de Ceratosauria, esse padrão evolutivo é encontrado em ambas as linhagens. Na presente tese a evolução de ambos os clados é testada utilizando morfometria geométrica nos elementos cranianos, além de medidas lineares e descrições qualitativas. Foram visitadas no total 17 coleções paleontológicas distribuídas no Brasil, Argentina, EUA, Mongólia e China a fim de coletar dados sobre terópodes. Os espécimes examinados foram fotografados, medidos e descritos. Os dados morfométricos foram tratados utilizando os softawares da série TPS e MorphoJ resultando em 54 landmarks nos caracteres cranianos. A fim de avaliar a relação entre os crânios e os landmarks, foram excluídos alguns landmarks do conjunto de dados original. Todos os conjuntos de dados resultantes mostraram poucas variações no morfoespaço, independente do número de landmarks. Foi concluído que a parte anterior do crânio desenvolve-se independentemente da região posterior, após a fenestra anterorbital, em ambos os clados. Ceratosauria é o clado com maior disparidade entre os terópodes carnívoros, especialmente Carnotaurus sastrei. Tyrannosauroidea apresentaram crânios mais conservativos. A disparidade morfológica está relacionada à antiguidade das linhagens e ampla distribuição geográfica. A análise de regressão linear demonstrou que Tyrannosaurus rex pode apresentar grande amplitude fenotípica durante o desenvolvimento ontogenético, e sugere que Nanotyrannus e Raptorex sejam sinônimos juniores de Tyrannosaurus e Tarbosaurus baatar respectivamente. O desenvolvimento ontogenético de Ceratosauria é difícil de avaliar, no entanto Limusaurus inextricabilis apresenta diversas mudanças cranianas durante a fase de crescimento, sugerindo perda de todos os dentes, migração posterior da fenestra pró-maxilar, aumento da órbita e rostro. Ceratosauria e Tyrannosauroidea aumentam de tamanho durante o desenvolvimento filogenético, mas apesar da estrutura corporal ser semelhante, não há convergência morfológica e funcional entre os dois clados. A única convergência entre Tyrannosauroidea e Ceratosauria parece ser ecológica. Tyrannosauridae gráceis como Gorgosaurus libratus, Alioramus altai e juvenis de Tyrannosaurus poderiam ter funções ecológicas semelhantes à Abelisauridae. Por outro lado, Tyrannosauridae mais robustos como Tyrannosaurus, Tarbosaurus e Daspletosaurus torosus poderiam xi ter um nicho mais amplo. Acerca da distribuição e funções ecológicas de Abelisauridae, esse clado poderia ter empurrado Carcharodontosauridae para a extinção, uma vez que ambos apresentam similares convergências craniodentárias e mecânicas.Theropods were the most successful dinosaurs during the Mesozoic Era, being still well diversied until recent times through the clade Aves. Among them, Tyrannosauroidea and Ceratosauria had a wide distribution, being commonly found on the Northern and Southern Hemispheres, respectively, in the Jurassic and Cretaceous Periods. Both were top predators, known in its basal form, to have small heads, long necks, long forelimbs and tails, whereas the most derived forms were characterized by a large head, short neck, short forelimb and tail. Although Tyrannosauroidea is not phylogenetically close to Ceratosauria, a similar developmental pattern is found in both lineages. In the present thesis, I assessed the evolutionary pattern of morphological shape in both clades using landmark-based geometric morphometric techniques on their skulls, along with some linear measurement and qualitative descriptions. Seventeen paleontological collections distributed in Brazil, Argentina, USA, Mongolia, and China were visited to collect data on these theropods. Specimens examined were photographed, measured and described. The morphometric data were treated using the software TPS series and MorphoJ resulting in 54 landmarks on skull characters. To assess different relationships among the landmarks and the skulls I excluded some landmarks in the original dataset. All datasets show few variations in morphospace, independent of the number of landmarks. Here, I conclude that the anterior part of the skull developed independently from the posterior part of the braincase (posterior to the antorbital fenestra) in both groups independently. Ceratosauria is the clade with more disparity among carnivorous theropods, especially when considering Carnotaurus sastrei. Tyrannosauroidea shows signs of having more conservative skulls. The development of morphological disparity is related to old lineages with long geographical distributions. The linear regression showed that Tyrannosaurus rex could have been more phenotypically spread during ontogenetic development, suggesting that Nanotyrannus and Raptorex are junior synonyms of Tyrannosaurus and Tarbosaurus baatar, respectively. Ontogenetic traits in Ceratosauria are difficult to assess, but Limusaurus inextricabilis showed high rates of change on its skull throughout its development, suggesting that they might loose all teeth, and have xii posterior migration of the promaxillary fenestra, increasing the orbit and snout during the ontogenetic development. Ceratosauria and Tyrannosauroidea show a tendency to larger and heaver forms from basal to more derived forms in their phyogeny. Although main body plan is similar in both group, there are neither morphological nor functional convergences between Ceratosauria and Tyrannosauroidea. The only observed convergence between Tyrannosauridae and Ceratosauria appears to be ecological. Gracile Tyrannosauridae such as Gorgosaurus libratus, Alioramus altai and juvenile Tyrannosaurus may have had similar ecological roles with Abelisauridae. On the other hand, Tyrannosauridae such as Tyrannosaurus, Tarbosaurus and Daspletosaurus torosus may have had a broader niche. Concerning distribution and ecological functions of Abelisauridae, this clade may have pushed another southern clade, the Carcharodontosauridae, to extinction since both clades had similar craniodental and mechanical skull morphologies.
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Bates, Karl T. "Body Size and Locomotor Biomechanics in Non-Avian Theropod Dinosaurs." Thesis, University of Manchester, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.518454.
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Kambic, Robert Emmett. "Multivariate analysis of avian and non-avian theropod pedal phalanges." Thesis, Montana State University, 2008. http://etd.lib.montana.edu/etd/2008/kambic/KambicR0508.pdf.
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The relationship between morphology and behavior in theropods was examined using multivariate analyses performed on a set of linear measurements of pedal non-ungual phalanges in a sample of 132 extant and 13 extinct taxa. Principal component analysis reveals that modern birds with terrestrial lifestyles tend to cluster away from those with raptorial and non-predatory grasping lifestyles although the division is not clean. Most non-avian dinosaurs tend to cluster with terrestrial species although Deinonychus and some Tyrannosaurids cluster with raptorial taxa. Terrestrial taxa tend to have phalanges that are comparatively shorter distally, are relatively wide, and have shallow grooving of the distal trochleae, while grasping taxa show opposing trends. Predatory graspers have proportionately wider phalanges than non-predatory graspers. Discriminant function analysis performs well in distinguishing among species with specialized behavior while taxa with less stereotyped behaviors are harder to classify. Predatory graspers are easily separated from non-predatory graspers. Troodon and Elmisaurus are grouped with terrestrial/cursorial taxa. Tyrannosaurus, Allosaurus, Daspletosaurus, and Albertosaurus are identified as terrestrial/cursorial with some possible predatory grasping ability. Deinonychus and Bambiraptor appear to have more grasping ability than Troodon.
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Sales, Marcos André Fontenele. "Contribuições à paleontologia de Terópodes não-avianos do Mesocretáceo do Nordeste do Brasil." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2017. http://hdl.handle.net/10183/181014.
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A Região Nordeste do Brasil apresenta um importante registro fóssil de dinossauros mesocretáceos, especialmente do clado Theropoda, popularmente referidos como terópodes. A quase totalidade dos espécimes é oriunda de dois depósitos sedimentares, a Formação Romualdo, Albiano da Bacia do Araripe, e a Formação Alcântara, Cenomaniano da Bacia de São Luís-Grajaú. A presente tese apresenta o estado da arte referente aos terópodes não-avianos das formações supracitadas, contextualizando-os do ponto de vista paleogeográfico e paleoecológico. A revisão dos principais achados é acompanhada por resultados inéditos obtidos pelo pós-graduando ao longo de seu Doutorado, dos quais os principais estão sumarizados a seguir: (1) a obtenção de evidência estatística para a associação positiva entre espinossaurídeos e paleoambientes costeiros; (2) o primeiro registro inequívoco do táxon Abelisauridae na Formação Alcântara; (3) o reconhecimento de uma distinção faunística entre a diversidade dinossauriana das formações Romualdo e Alcântara; (4) a identificação das coroas dentárias maxilares do espinossaurídeo Irritator challengeri; (5) a obtenção de uma nova hipótese para as relações filogenéticas entre os espinossaurídeos brasileiros e os demais táxons. Estes resultados, acompanhados de outros, possuem implicações taxonômicas, evolutivas, paleobiogeográficas e paleoecológicas. Por exemplo, a maior abundância de somatofósseis de espinossaurídeos nas formações mencionadas provavelmente está relacionada à associação positiva entre estes terópodes e os paleoambientes costeiros. Por outro lado, a identificação das coroas dentárias maxilares de I. challengeri, em conjunto com os resultados cladísticos, permitiram a reapreciação de detalhes relativos à evolução das narinas externas de espinossaurídeos, bem como a refutação da hipótese de que o holótipo desta espécie é parte do mesmo espécime do holótipo de Angaturama limai. Ademais, a análise cladística realizada sugere que o clado Baryonychinae não é monofilético. Por fim, o reconhecimento da presença de abelissaurídeos na Formação Alcântara está de acordo com a abundância deste táxon em depósitos sedimentares gondwânicos durante o mesocretáceo, reforçando as semelhanças existentes com os depósitos mesocretáceos africanos, ao mesmo tempo em que salienta as diferenças entre esta unidade e a Formação Romualdo quanto à diversidade de dinossauros. Isto sugere que a fauna dinossauriana da América do Sul era mais heterogênea do que previamente assumido por outros autores, o que deve ser levado em consideração quando de análises futuras de similaridade de faunas. No entanto, a despeito do que já se conhecia e dos novos dados aportados por esta tese, muitas outras questões ainda permanecem por serem investigadas mais a fundo. Desta forma, esta contribuição se constitui em um passo adicional – porém nunca definitivo – no propósito de expandir o conhecimento sobre os terópodes não-avianos do mesocretáceo do Nordeste do Brasil.The northeastern Brazil has yielded an important fossil record of Mid- Cretaceous dinosaurs, especially the clade Theropoda. Almost all specimens come from two fossiliferous deposits, the Romualdo Formation, Albian of the Araripe Basin, and the Alcântara Formation, Cenomanian of the São Luis-Grajaú Basin. This thesis presents the state of the art relative to the nonavian theropods from the aforementioned formations, contextualizing them paleobiogeographically and paleoecologically. The review of the findings is followed by the inedit results gathered by the PhD candidate during his Doctorate, among which the main ones are summarized below: (1) the obtention of statistical evidence of the positive association between spinosaurids and coastal paleoenvironments; (2) the first unequivocal record of Abelisauridae from the Alcântara Formation; (3) the recognition of a faunal distinction between the dinosaur diversity of the Alcântara and Romualdo formations; (4) the identification of the maxillary tooth crowns of the spinosaurid Irritator challengeri; (5) the obtention of a new hypothesis of the phylogenetic relationships between the Brazilian spinosaurids and the other taxa. These results, along with others, have taxonomic, evolutionary, paleobiogeographic and paleoecological implications. For example, the greater abundance of spinosaurid body fossils in the those formations are likely related to the positive association between these theropods and coastal paleoenvironments. On the other hand, the identification of the maxillary tooth crowns of I. challengeri, along with the cladistic results, enabled the reanalysis of some details of the evolution of the external nares of spinosaurids, as well as the refutation of the hypothesis of the holotypes of this species and Angaturama limai belonging to the same specimen. Furthermore, the cladistic analysis suggests that Baryonychinae is not monophyletic. Finally, the record of abelisaurids from the Alcântara Formation is in agreement with the abundance of this taxon in Gondwanan deposits during the mid-Cretaceous, which strengthens the similarities with African mid-Cretaceous deposits, whereas it emphasizes the differences in dinosaur diversity between this unity and the Romualdo Formation. This suggests that the dinosaur fauna of South America was more heterogeneous than previously assumed by other authors, which must be taken into account by future analyses of similarities. Despite what was previously known and the new findings provided by this thesis, many other issues are still to be further investigated. Thus, this contribution is actually an additional step – although not the definite one – towards the expansion of the knowledge on mid-Cretaceous nonavian theropods from northeastern Brazil.
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Griffin, Christopher T. "The evolution of intraspecific variation, growth, and body size in early theropod dinosaurs." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/73682.
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Understanding the changes undergone during the life of an organism is often crucial to properly interpreting the evolutionary history of a group. For extinct organisms, this process can only be directly studied through growth series of fossils representing individuals at different stages of maturity. The growth patterns of the earliest dinosaurs (230–190 million years ago), in particular the morphological changes undergone during the life history of an individual (i.e., ontogeny) is poorly understood.
To tackle this problem, I studied the changes undergone during growth of two early theropod dinosaurs, Coelophysis bauri and Megapnosaurus rhodesiensis. To reconstruct the growth of these dinosaurs I used ontogenetic sequence analysis (OSA). I found that, unlike living birds, early dinosaurs possessed an extremely high amount of intraspecific variation in growth. This variation had been previously interpreted as sexual difference; however, I found no evidence of this. Because this variation is widespread among early dinosaurs and their relatives, I hypothesize that this is the ancestral condition of dinosaurian growth, and that this was lost along the evolution to birds. These ontogenetic events are conserved through evolution, and I used this to assess the maturity of large Triassic theropods: I suggest that all known large-bodied Triassic theropods were still growing rapidly at death, and that the maximum body size of Triassic theropods was higher than previously supposed. Theropods were large before the end Triassic mass extinction, unlike what has been previously hypothesized.Master of Science
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Benson, R. B. J. "The taxonomy, systematics and evolution of the British theropod dinosaur Megalosaurus." Thesis, University of Cambridge, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.596577.
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The Middle and Late Jurassic theropod (Dinosauria: Archosauria) record of Britain is reviewed to support the inclusion of taxa from these time periods in a new cladistic analysis constructed to elucidate basal tetanuan relationships. British Middle Jurassic deposits have yielded the most abundant theropod fossil material of this age world-wide. The most productive British theropod localities of this epoch are Bathonian in age: Stonesfield, Oxfordshire and New Park Quarry, Gloucestershire. The large-bodied theropod assemblages of these localities are interpreted as monospecific. Abundant remains from these localities can be referred to Megalosaurus, the historically oldest dinosaur taxon. Two additional large-bodied tetanurans were present in British Bathonian Dinosaur ecosystems based on more fragmentary fossils. A minimum of two further, small-bodied taxa are indicated by teeth and postcranial remains. The British Late Jurassic strata are less productive but yield new data that contribute toward global biogeographic scenarios. Metriacanthosaurus (Oxfordian) is a sinraptorid allosauroid, Stokesosaurus (Tithonian) is a basal tyrannosauroid, and isolated remains of robust, large-bodied theropods (Kimmeridgian-Tithonian) show affinities with Megalosaurus or its sister taxon Torvosaurus. A new cladistic analysis focussing on basal tetanuran relationships includes 213 characters (of which 22 are new) and 41 taxa. Several of these taxa have never been included in a cladistic analysis: Chuandongocoelurus, Marshosaurus, Piveteaursaurus, ‘Megalosaurus’ hesperis and Magnosaurus nethercombensis. The content of groups within Spinosauroidea corresponds well with geography, indicating limited endemism across Pangaea among theropods of this age. Most Late Jurassic large-bodied theropods are allosauroids, and allosauroids are also abundant during this time period. This suggests faunal turnover between the Middle and Late Jurassic.
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Henderson, Donald Mackenzie. "A mathematical and computational analysis of the biomechanics of walking theropod dinosaurs." Thesis, University of Bristol, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.297709.
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Allain, Ronan. "Les Megalosauridae (Dinosauria, Theropoda) : Nouvelle découverte et révision systématique : implications phylogénétiques et paléobiogéographiques." Paris, Muséum national d'histoire naturelle, 2002. http://www.theses.fr/2002MNHN0011.
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Les Megalosauridae (Dinosauria, Theropoda) sont l'un des groupes les plus énigmatiques de dinosaures carnivores, n'étant connu[e]s que par un matériel relativement fragmentaire en comparaison avec celui des autres dinosaures carnivores. Le découverte de Poekilopleuron ? valesdunensis nov. Sp. Dans le Jurassique moyen de Normandie nous apporte de nombreuses informations sur l'anatomie de ces théropodes et sert de base à une révision détaillée des autres genres de théropodes européens, couramment rattachés aux Megalosauridae. Megalosaurus bucklandii, premier théropode non-avien jamais décrit, est considéré comme un nomen dubium. Deux analyses de parcimonie basée sur une matrice de données comportant 107 caractères ostéologiques contrôlés d'abord chez 18 taxons, et ensuite chez 24 taxons ont été réalisées. L'arbre de consensus strict de l'analyse à 24 taxons (234 pas ; CI=0,61 ; RI=0,75) est de la forme (Tetanurae (Spinosauridae (Spinosauridae + Megalosauridae) + Neotetanurae (Allosauroidae + Coelurosauria))). Les Megalosauridae apparaissent monophylétiques et incluent les genres Poekilopleuron, Eustreptospondylus, Streptospondylus, Lourinhanosaurus et Afrovenator. Metriacanthosaurus et Erectopus, longtemps considérés comme proches des Megalosauridae, sont rattachés aux Allosauroidae. Une nouvelle classification des théropodes est proposée. L'arbre phylogénétique tiré des analyses de parcimonie indique que les lignées menant aux Ceratosauria, aux Spinosauroidea, aux Allosauroidae et aux Coelurosauria étaient déjà individualisées au Jurassique inférieur ? L'inclination de l'ensemble des Spinosauroidea à un régime alimentaire piscivore est suggérée.
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Snively, Eric. "Rigid Body Mechanics of Prey Capture in Large Carnivorous Dinosaurs." Ohio University / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1322668677.
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Samathi, Adun [Verfasser]. "Theropod dinosaurs from Thailand and Southeast Asia : phylogeny, evolution, and paleobiogeography / Adun Samathi." Bonn : Universitäts- und Landesbibliothek Bonn, 2019. http://d-nb.info/120002012X/34.
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Klingler, Jeremy Joseph. "Lateral tracheal and esophageal displacement in Avialae and morphological implications for theropoda (Dinosauria| Saurischia)." Thesis, Northern Illinois University, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1591019.
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This research examines the evolution, phylogenetic distribution, and functional explanations for a peculiar and often overlooked character seen in birds, herein called tracheal and esophageal displacement. Of special interest to this study is examining whether the trait was present in non-avian theropod dinosaurs. This study found that essentially all birds are characterized by a laterally displaced trachea and/or esophagus. The displacement may occur gradually along the neck, or it may happen immediately upon exiting the oropharynx. Displacement of these organs is the result of a heavily modified neck wherein muscles that create mobility restrictions in lizards, alligators, and mammals (e.g., m. episternocleidomastoideus, m. omohyoideus, and m. sternohyoideus) no longer substantially restrict positions in birds. Rather, these muscles are modified, which may assist with making tracheal movements.
An exceptionally well-preserved fossil theropod, Scipionyx samniticus , proved to be paramount. Its in situ tracheal and esophageal positions and detailed preservation (showing the hallmarks of displacement including rotation, obliquity, a strong angle, and a dorsal position in a caudad region of the neck) demonstrate that at least some theropods were characterized by tracheal and esophageal displacement. Ultimately, the presence of the trait correlates with a highly flexible neck, allowing slack and permitting for the organs to save length as they avoid the long curves of the S-shaped neck.
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Biskis, Veronika N. "Feathered dinosaurs and the origin of avian flight." Thesis, Boston University, 2013. https://hdl.handle.net/2144/21125.
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Thesis (M.A.) PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.It is now widely accepted that modern day birds originated from the clade Theropoda represented by bipedal carnivorous dinosaurs that thrived between the late Triassic and Cretaceous period. New research illustrates how the evolutionary assembly of the avian body plan began in these theropods with small fore limbs, large hind limbs and stiff tails, and progressed through a series of increasingly bird-like, transitional anatomical stages. There is also a great deal of homoplasy among dinosaurs however, or evolution of the same traits in distantly related groups, which makes it even more difficult to pinpoint the phylogenetic relationships among theropods. A limited fossil record and confusing temporal inconsistency has also led paleontologists and ornithologists alike to dismiss this crucial connection. They often attribute the origin of birds instead to a basal archosaur, ancestor to both dinosaurs and crocodilians. However the recent discoveries of feathered non-avian theropods, especially from the Late Jurassic and Early Cretaceous of Liaoning, China may finally lay the argument to rest. The scientific community has remained especially divided over to what degree feathers and other flight characteristics are present amongst the advanced theropods, and Dinosauria in general. Understanding this distinction helps separate each species into separate clades along the cloudy phylogenetic timeline as a function of feather development, and therefore offers insight into where they initially became functional for flight. Because fossils depicting defined integumental structures have been recently uncovered by the hundreds over the last 20 years, there is more evidence of this transition than ever. Through studies of theropod and avian physiology, we can gain more insight into the macroevolutionary principles and selective pressures that led dinosaurs to take to the sky.
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Naish, Darren William. "The osteology and affinities of Eotyrannus lengi and Lower Cretaceous theropod dinosaurs from England." Thesis, University of Portsmouth, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.429784.
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Rayfield, Emily Jayne. "Cranial form and function in a large theropod dinosaur : a study using finite element analysis." Thesis, University of Cambridge, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.620229.
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Palma, Liberona José Antonio. "Caracterización de una relación alométrica en Theropoda (dinosauria) con énfasis en su extensión e implicaciones evolutivas." Tesis, Universidad de Chile, 2018. http://repositorio.uchile.cl/handle/2250/163999.
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Tesis entregada a la Universidad de Chile en cumplimiento parcial de los requisitos para optar al grado de Magíster en Ciencias Biológicas.El origen del vuelo en Aves está marcado tanto por disminuciones significativas en tamaño corporal como por el aumento en tamaño relativo de las extremidades anteriores. No obstante, previo al origen del vuelo, la evolución de ambos caracteres pudo estar asociada mediante de un patrón alométrico evolutivo negativo para las extremidades anteriores de terópodos. Esta relación ha sido descrita para la mayor parte de Theropoda, perdiéndose en la base de Aves (desde Archaeopteryx lithographica), clado donde se describen en su lugar isometrías o alometrías positivas tanto evolutivas como ontogenéticas. No obstante, las publicaciones donde estas alometrías han sido descritas no corrigen apropiadamente la no-independencia estadística presente entre especies emparentadas. Además, a pesar de que se ha sugerido, ningún estudio a la fecha ha evaluado formalmente la posibilidad de la pérdida del patrón de alometría evolutiva negativa para extremidades anteriores en otros taxa pertenecientes a Theropoda. Del mismo modo la posible relación entre el patrón alométrico evolutivo negativo para extremidades anteriores y un patrón equivalente en la ontogenia no ha sido discutida. En el presente estudio se procedió a re-evaluar el patrón alométrico evolutivo negativo para extremidades anteriores en Theropoda, además de posibles desviaciones respecto a este, utilizando datos de longitudes de húmero y fémur correspondientes a 163 especímenes distribuidos en 108 géneros, incorporando variabilidad intraespecífica, incerteza filogenética y dos modelos evolutivos alternativos a las correcciones filogenéticas utilizadas en los análisis realizados. Mediante estos análisis se recuperaron valores de alometría negativa para el conjunto de los terópodos no-avianos encontrándose además que Coelophysoidea, Ornithomimosauria y Oviraptorosauria presentan diferencias significativas respecto al patrón alométrico general bajo ambos modelos evolutivos, exhibiendo isometría. Se encontró alometría evolutiva negativa para extremidades anteriores en Dromaeosauridae, corroborando que, probablemente, este patrón alométrico evolutivo estaba presente en formas cercanas a Aves. Al revisar la evidencia publicada respecto a alometrías negativas ontogenéticas para extremidades anteriores en Theropoda se encontraron patrones similares a los patrones alométricos evolutivos obtenidos, del mismo modo esta correspondencia se encontró en Aves y otros clados cercanos a Theropoda permitiendo proponer que, además de una órbita y caja craneana expandidas, la paedomorfosis observada en el origen de Aves incluyó extremidades anteriores proporcionalmente mayores como otro rasgo juvenil.
The origin of flight in Aves is marked both by significant decreases in body size and by the increase in relative forelimb size. However, before the origin of flight, the evolution of both characteristics may have been coupled through a pattern of negative forelimb evolutive allometry in Theropoda. This pattern was lost at the origin of Aves (since Archaeopteryx lithographica), clade where isometry or positive allometry has been described instead for both: the phylogeny and ontogeny. However, the publications where these allometries have been described do not properly correct for the statistical non-independence present among related species. Furthermore, even though it has been suggested, no study has formally tested if other taxa in Theropoda show loss of the negative allometric pattern as well. Similarly, the possible relation between the negative forelimb evolutive allometric pattern and an equivalent ontogenetic one has not been discussed. In the present study we re-evaluated the negative forelimb allometric pattern found in the evolution of Theropoda and tested for significate deviations from it using femur and humerus lengths from 163 specimens representing 108 genera, we also incorporated intraspecific variation, phylogenetic uncertainty and two alternative evolutionary models to the phylogenetic corrections used in the analyses. We recovered an evolutionary negative forelimb allometry for all non-avian theropods; we also identified that Coelophysoidea, Ornithomimosauria and Oviraptorosauria show significative differences from the general allometric pattern presenting isometry. We found evolutionary negative forelimb evolutive allometry in Dromaeosauridae showing that this pattern was, most likely, still present in forms close to Aves. Upon reviewing published evidence for ontogenetic negative forelimb allometry in Theropoda we found similar patterns to the ones obtained through our analysis, we also observed similarities between ontogenetic and evolutive forelimb allometric patterns described for Aves and other taxa close to Theropoda suggesting that, in addition to an expanded orbit and braincase, the paedomorphosis observed at the origin of birds probably included proportionally larger arms as another juvenile trait.
Proyecto Anillo ACT172099 y Fondecyt 1150906.
Julio 2019
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Dufeau, David L. "The Evolution of Cranial Pneumaticity in Archosauria: Patterns of Paratympanic Sinus Development." Ohio University / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=ohiou1313622931.
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Abrahams, Miengah. "Evaluation of tridactyl theropod tracks in southern Africa: quantitative morphometric analysis across the Triassic–Jurassic boundary." Doctoral thesis, Faculty of Science, 2020. http://hdl.handle.net/11427/32436.
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In the Mesozoic, dinosaur abundance and diversity steadily increased from the Carnian to the Triassic booming soon after the end Triassic Mass-Extinction event (ETE), marking a key period in archosaur history. In southern Africa, the Triassic–Jurassic Boundary (TJB) is contained in the richly fossiliferous, fluvio-lacustrine-aeolian Upper Triassic to Lower Jurassic strata of the Stormberg Group. More specifically, the middle Norian – Pliensbachian Elliot and Clarens formations (upper Stormberg Group) of main Karoo Basin, host a diverse tetrapod osteological and ichnite record. Due to an absence of high resolution radioisotopic age determinations, the exact stratigraphic placement of the TJB remains unknown. Although diverse ichnofossils attributed to Saurischians and Ornithischians are preserved in the Stormberg Group, the record is dominated by isolated tridactyl tracks that can be assigned to common ichnogenera like Grallator, Eubrontes and Kayentapus. Ideally, these track morphologies would reflect the trackmaker's autopod morphology, but complex interactions between the trackmaker and tracking substrate may affect the final footprint shape. Tracks with a high morphological preservation grade may be used to infer information (e.g., body length, hip height, weight) about the trackmaker, which is especially useful when skeletal remains are scarce, as is the case with theropod body fossils in the Elliot and Clarens formations. Herein, we present the findings of an extensive southern African field-based study to quantify the morphological variation of Grallator, Eubrontes and Kayentapus tracks across the TJB in the upper Stormberg Group. Furthermore, this study produced the first detrital zircon Uranium–Lead (U-Pb) LA-ICPMS ages of the major ichnosites from this region, and confirmed that the TJB is within the Elliot Formation, near the boundary of the lower and upper Elliot Formation (i.e., near the contact of the informal lEF and uEF). Across this contact, the considered tridactyl tracks become more abundant, larger and have a less pronounced medial digit projection. These morphological changes are gradational, with tracks from the Clarens Formation being distinct to tracks from the lEF, while the uEF tracks being intermediate between the lEF and Clarens Formation. A decrease in the mesaxony (Dp/TS ratio) and a decrease in medial digit projection relative to track length can be detected in both small and large tridactyl tracks. These apparent trends in the upper Stormberg Group are consistent with global tridactyl trends, which suggest an overall increase in theropod abundance and body size across the Jurassic. Moreover, the reason for the less prominent medial pedal digit is linked to a better weight distribution across the autopod in the increasingly larger theropods. Last but not least, Grallator, Eubrontes and Kayentapus ichnogenera which may be attributed to at least three different groups of theropod-like trackmakers, suggest a higher palaeo-diversity and abundance of tridactyl dinosaurs in southern Africa than is known from the osteological record.
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Michard, Jean-Guy. "Description du compsognathus (saurischia, theropoda) de canjuers (jurassique superieur du sud-est de la france). Position phylogenetique, relation avec archaeopteryx et implications sur l'origine theropodienne des oiseaux." Paris 7, 1991. http://www.theses.fr/1991PA077064.
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La description comparative detaillee du petit theropode des calcaires lithographiques de canjuers (tithonique inferieur, var, france) a permis de le rapporter au genre et a l'espece compsognathus longipes wagner, 1859 (c. Corallestris bidar, demay et thomel, 1972). Cette etude a conduit a une nouvelle interpretation de certaines structures anatomiques de ce genre, notamment de la morphologie du metacarpe, comparable a celle de nombreux autres theropodes de petite taille. Une analyse cladistique, realisee sur la base des travaux de gauthier (1986), place compsognathus au sein des tetanurae et l'eloigne ainsi de sa position presumee proche d'archaeopteryx et des oiseaux
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Baron, Matthew Grant. "The origin and early evolution of the Dinosauria." Thesis, University of Cambridge, 2018. https://www.repository.cam.ac.uk/handle/1810/271890.
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For 130 years dinosaurs have been divided into two distinct clades – Ornithischia and Saurischia. This dissertation looks at the earliest evolution of the clade Dinosauria by focusing upon the interrelationships of the major subsidiary clades within it. It does this following examination, comparison and description of early dinosaur material, and by utilising modern phylogenetic analysis techniques, to rigorously and objectively test the fundamental groupings within the clade Dinosauria using a newly compiled dataset of early dinosaurs and other dinosauromorphs (= close dinosaur relatives). The current consensus on how the principal clades within Dinosauria (Theropoda, Sauropodomorpha and Ornithischia) are related to one another is challenged by the results of these analyses. This study finds, for the first time, a sister-group relationship between Ornithischia and Theropoda, here termed Ornithoscelida. Consequently, a new definition for Dinosauria is presented, as the historic definition would exclude all members of Sauropodomorpha from the clade. As well as this, I propose revisions to the definitions of each of the principal dinosaurian sub-divisions and propose a new timeframe and geographic setting for the origin of Dinosauria. These new hypotheses force re-evaluations of early dinosaur cladogenesis and character evolution, suggest the independent acquisition of hypercarnivory in multiple dinosaur groups and offers an explanation for many of the anatomical features previously regarded as striking convergences between theropods and early ornithischians. As well as presenting new anatomical data on many early dinosaurs and dinosauromorphs, including a comprehensive re-description of the postcranial anatomy of Lesothosaurus diagnosticus (Chapter 2), and a new anatomical dataset of early dinosaurs (the largest ever compiled), this thesis goes on to implement the new dataset to investigate a number of important outstanding questions about early dinosaur evolution and provides new lines of enquiry for future workers to pursue. The results of this thesis reveal the oldest known members of the dinosaurian clades Theropoda and Sauropodomorpha (Chapter 6), as well as a new clade within Ornithischia; a taxon previously thought to represent a derived theropod has been recovered as a potential ‘missing link’ between theropods and ornithischians using the new dataset. This work now provides a unique tool for the assessment of the phylogenetic affinities of early dinosaurs and dinosauromorphs and, once published, will hopefully become the benchmark dataset for palaeontologists working in this area.
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Tykoski, Ronald S. "Anatomy, ontogeny, and phylogeny of coelophysoid theropods." Thesis, 2005. http://wwwlib.umi.com/cr/utexas/fullcit?p3184532.
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Brusatte, Stephen. "The Phylogeny of Basal Coelurosaurian Theropods (Archosauria: Dinosauria) and Patterns of Morphological Evolution during the Dinosaur-Bird Transition." Thesis, 2013. https://doi.org/10.7916/D86979NW.
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Theropod dinosaurs are an iconic and familiar group of extinct species that include predators such as Tyrannosaurus and Velociraptor, as well as an array of other Mesozoic taxa. Carnivorous theropods are the evolutionary ancestors of birds, and the evolutionary transition between theropods and birds is a textbook example of a major evolutionary transformation in the history of life. Despite a flurry of research on early birds and their dinosaurian relatives, however, several questions still remain. First, the anatomy of some major theropod groups has yet to be described in detail. Second, there is little consensus on the phylogenetic relationships of the basal members of a theropod subgroup called Coelurosauria: the clade of birds and their closest relatives (defined as all taxa closer to birds than to Allosaurus). Third, there has been little synthetic work on large-scale macroevolutionary patterns during theropod evolution. This dissertation includes three chapters that touches on these three major issues. Chapter 1 is a detailed description of the Late Cretaceous tyrannosaurid theropod Alioramus altai, based on its holotype specimen from the Tsaagan Khuushu locality in the Maastrichtian Nemegt Formation of Mongolia. This monographic description provides further evidence that Alioramus is an unusual long-snouted, gracile, and slender-limbed taxon with an unpredecented degree of cranial ornamentation among tyrannosaurids and an extremely pneumatized skeleton. Anatomical comparisons indicate that the long skull of Alioramus is an autapomorphic feature that is proportionally longer (relative to femur length) than in any other known tyrannosaurid specimen, including juveniles, and that Alioramus is morphologically distinctive relative to similarly-sized individuals of the contemporary and sympatric Tarbosaurus. The coexistence of the long-snouted Alioramus and robust and deep-snouted Tarbosaurus, which are found together at the Tsaagan Khuushu locality, demonstrate that multiple large tyrannosaurids were able to live in sympatry, likely because of niche partitioning due to differences in craniofacial morphology and functional behavior. Chapter 2 presents a comprehensive new phylogenetic analysis of coelurosaurian theropods, which is an updated version (and thus the latest iteration) of the long-standing Theropod Working Group (TWiG) analysis. The new analysis incoroporates a wealth of new taxa and character data into the TWiG matrix for the first time, most of which is relevant to basal (non-maniraptoran) coelurosaurs such as tyrannosauroids and ornithomimosaurs, which had previously been the subject of only cursory character and taxon sampling in TWiG studies. The full dataset was analyzed under parsimony, and the resulting phylogeny includes several well supported relationships and agrees with previous analyses in many aspects. As a result, it is argued that a consensus view of basal coelurosaurian relationships has emerged, including: 1) the monophyly of major subclades such as Tyrannosauroidea, Compsognathidae, and Ornithomimosauria; 2) the position of the singleton genera Bicentenaria, Zuolong, and Tugulusaurus near the base of Coelurosauria; 3) the placement of Tyrannosauroidea as the most basal major coelurosaurian subclade; 4) the inclusion of Guanlong, Dilong, and Proceratosaurus within Tyrannosauroidea; 5) the existence of a derived maniraptoran clade that includes alvarezsauroids, therizinosauroids, oviraptorosaurs, and paravians to the exclusion of ornithomimosaurs and tyrannosauroids. Remaining areas of uncertainty include the phylogenetic position of Compsognathidae and the singleton genus Ornitholestes, and relationships at the base of the Ornithomimosauria + Maniraptora clade and Maniraptora itself. The phylogeny indicates that much of the early history of Coelurosauria has yet to be sampled in the fossil record, that coelurosaurs originated at small body size, and that the evolution of the iconic Tyrannosaurus-like bauplan occurred only towards the end of the Cretaceous. Chapter 3 presents a geometric morphometric analysis that is used to study broad patterns in theropod skull shape variation and compare the distribution of taxa in cranial morphospace (form) to both phylogeny and quantitative metrics of biting behaviour (function). The analysis finds that theropod skulls primarily differ in relative anteroposterior length and snout depth and to a lesser extent in orbit size and depth of the cheek region, and that oviraptorosaurs deviate most strongly from the "typical" and ancestral theropod morphologies. Noncarnivorous taxa generally fall out in distinct regions of morphospace and exhibit greater overall disparity than carnivorous taxa, whereas large-bodied carnivores independently converge on the same region of morphospace. The distribution of taxa in morphospace is strongly correlated with phylogeny but only weakly correlated with functional biting behaviour. These results imply that phylogeny, not biting function, was the major determinant of theropod skull shape.
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White, Matt. "The revised skeletal description and biological range of motion analysis of Australia’s most complete theropod dinosaur Australovenator wintonensis (Theropoda: Megaraptoridae)." Thesis, 2017. http://hdl.handle.net/1959.13/1335870.
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Research Doctorate - Doctor of Philosophy (PhD)The following PhD focuses on better understanding the skeleton of Australia’s most complete carnivorous theropod dinosaur Australovenator wintonensis. It belongs to a family group of dinosaurs known as Megaraptoridae. It is a relatively poorly known group of theropod dinosaurs with only partially preserved skeletons. This research dramatically improves the knowledge of the Australovenator skeleton and provides a unique perspective on its potential range of motion which is coupled with skeletal morphological knowledge in an effort to understand where this theropod is phylogenetically situated. Further preparation of the holotype specimen led to the discovery of near complete forearms, hindlimbs, dentary and teeth which are described herein. Descriptions of these elements were vital for better understanding this relatively poorly known group of dinosaurs (Megaraptorids) and provide more information on the phylogeny of Australovenator. The morphological comparisons with other theropods especially ones found in Australia indicated that there were similarities with Rapator ornitholestoides a theropod dinosaur that was described off a single metacarpal I. The discovery of right metacarpal I of Australovenator enabled a more accurate comparison with Rapator which established that the two genera are distinctly different. The complete hind limb revealed that the metatarsus was primitive in design similar to Allosauroids however it was distinctly more elongate than the much stockier Allosaurus pes. This feature alone was interpreted here as being a more derived morphological feature. A variety of innovative digital techniques have been employed to analyze the skeletal range of motion and assist in the biological restoration of various aspects of the Australovenator skeleton. The forearm range of motion analysis revealed Australovenator shared similar range of motion limitations with both highly derived tetanurans and very basal coelurosaurs. Pedal range of motion and biological restoration enabled the attempted replication of its corresponding footprints. These were used to compare with the largest bipedal prints preserved at Lark Quarry in central Queensland, Australia. The comparison determined that the largest Lark Quarry prints were made by a theropod and quite possibly if not Australovenator a theropod of equivalent size. The range of motion of skeletal elements has not been completed for any other Megaraptorid and therefore this research forms the basis for future comparisons within the group. The aim of this research is to provide in a better understanding of not only where Australovenator is situated phylogeneticaly but which theropod branch Megaraptoridae more closely belongs either tetanuran or coelurosaurian.
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Franzosa, Jonathan William Rowe Timothy. "Evolution of the brain in Theropoda (Dinosauria)." 2004. http://wwwlib.umi.com/cr/utexas/fullcit?p3127086.
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Franzosa, Jonathan William. "Evolution of the brain in Theropoda (Dinosauria)." Thesis, 2004. http://wwwlib.umi.com/cr/utexas/fullcit?p3127086.
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Niedzwiedzki, Grzegorz. "The large predatory archosaur Smok wawelski from the latest Triassic of Poland." Doctoral thesis, 2013. https://depotuw.ceon.pl/handle/item/390.
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Numerous skull and mandible bones, elements from axial skeleton, pelvic and limb bones (in total 76 elements, both bones and bone fragments) of the latest Triassic (about 210–205 Ma) large predatory archosaur, Smok wawelski Niedźwiedzki, Sulej et Dzik, 2012 were found in close proximity (within 30 metres) at the Lipie Śląskie clay-pit in Lisowice in southern Poland. They are interpreted as belonging to the same individual; a few more bones (premaxilla, jugal, splenial and part of pubis) and isolated teeth collected in this site belong to other individuals. The type specimens represent ca 50% of the skeleton. S. wawelski was associated with small archosaurs (poposaurid, pterosaur, dinosauriform and small theropod dinosaur), a giant dicynodont, as well as an early mammal (or cynodont), rhynchosaur, choristodere-like diapsid, capitosaur and plagiosaur amphibians. Paleobotanical and conchostracan evidence indicate latest Norian-early Rhaetian age for the assemblage. S. wawelski is the largest and most robustly built predatory archosaur yet reported from the Late Triassic deposits of Europe. The estimated length of the entire skeleton of S. wawelski is 5–6 m, but footprint record suggests even larger size (6–7 m). Injuries left on the bones by another individual of presumably the same species indicate aggressive behaviour. One of the injuries (broken femur) was the apparent cause of the most completely preserved individual death. S. wawelski fed on juvenile and subadult dicynodonts, as shown by traces of its teeth on bones of the prey. Most traces are on the dicynodont hind limbs and pelvic bones suggestive of specialised hunting behaviour. Faeces and gastric pellets attributed to S. wawelski contain pieces of dicynodont bones, but the main source of food were probably fishes and other small tetrapods. The stable isotope record (carbon and oxygen) of the teeth enamel shows seasonality of the Late Triassic environment or in food availability (or record long-distance migration). The sutures between neural arches and centra of cervical vertebrae, and bones in braincase and pelvic were not closed, suggesting immaturity of the collected individual. Proportions of the postcranial skeleton of S. wawelski suggest that it may have been an obligate biped. Tridactyl foot imprints preserved in the same locality in sandstone layers located above and below bone-bering deposits, the largest 55 cm in length, together with the pelvis structure and femur construction, place S. wawelski at least close to bipedal and tridactyl forms in the dinosaurs lineage. They are more derived than those known from the Carnian–Norian, and correspond rather to the late Rhaetian–Early-Mid Jurassic grade. The vertically disposed and partially closed acetabulum with a slit-like perforation, prominent supraacetabular crest, antitrochanter on the ilium, femur with trochanteric shelf and two primordial sacral vertebrae broadly attached to the ilium, make it similar to basal predatory dinosaurs (e.g., Herrerasaurus ischigualastensis), whereas the conical base of basisphenoid in braincase is a highly advanced feature known only in neotheropod dinosaurs from the Early Jurassic (e.g., Sinnosaurus triassicus) and Mid Jurassic (e.g., Piatnitzkysaurus floresi). It is possible that Herrerasaurus–Smok lineage includes the ancestor of large neotheropod dinosaurs (Ceratosauria and Tetanurae) from Jurassic and Cretaceous periods. However, the traits shared with the “rauisuchians” (e.g., Postosuchus kirkpatricki) and other non-dinosaur archosaurs or archosauriforms may mean that S. wawelski is a representative of evolutionarily “primitive” dinosaur-like species (large predatory dinosauriform or basal dinosaur) from the latest Triassic, with numerous plesiomorphies typical for more basal archosaurs.
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Malafaia, Elisabete. "Phylogenetic analysis, paleoenvironmental and paleobiogeographic interpretation of theropod dinosaurs from the Upper Jurassic of the Lusitanian Basin." Doctoral thesis, 2017. http://hdl.handle.net/10451/35031.
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Tese de doutoramento, Geologia (Paleontologia e Estratigrafia), Universidade de Lisboa, Faculdade de Ciências, 2017The currently known record of Upper Jurassic theropod dinosaurs from the Lusitanian Basin is relatively abundant and diverse. It includes mainly medium to large-sized forms belonging to primitive theropod clades, such as Ceratosauria, or Tetanurae, including Megalosauridae and Allosauroidea. Small-sized and more derived theropods have also been identified based mainly on isolated elements. This study provides new information about the Portuguese Upper Jurassic record of theropod dinosaurs. The main objective of this research is to improve the knowledge about the evolutionary history of these dinosaur faunas. Several unpublished specimens collected in different sites of the Consolação, Turcifal and Bombarral-Alcobaça sub-basins indicate the presence of previously unidentified clades, including non-megalosaurid megalosauroids and a form of derived allosauroid closely related with Carcharodontosauria. These new specimens suggest a greater diversity among the Late Jurassic theropod faunas from the Lusitanian Basin than previously known. The Late Jurassic theropod fauna of the Lusitanian Basin have been traditionally interpreted as being closely related to those of correlative sedimentary sequences from the North American Morrison Formation and from the African Tendaguru Formation. Most of the genera currently known in the Portuguese record have a closely related taxon at the North American record and most of them were previously interpreted as belonging to species shared by both landmasses. However, more recently the Portuguese forms have been reinterpreted as separate species exclusive for the Lusitanian Basin. This faunal composition seems to indicate an incipient vicariant evolution of the dinosaur faunas from the Late Jurassic of the Lusitanian Basin suggesting that the seaway(s) between North America and Iberia represented barriers to the dispersion of these faunas. However, these barriers may have had different effects on different species, which would explain the stronger affinities of the fauna of theropods between the Lusitanian Basin and Morrison Formation than those of other dinosaur faunas such as the sauropods. Despite this similarity, it has been identified in the Portuguese record some dinosaur groups that apparently are absent in correlative North American strata and that are more closely related with Gondwanan faunas. These differences may indicate differential patterns of regional extinction and ecological constraints such as environmental preferences.
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Hendrickx, Christophe. "Evolution of Teeth and Quadrate in Non-avian Theropoda (Dinosauria: Saurischia), with the Description of Torvosaurus Remains from Portugal." Doctoral thesis, 2015. http://hdl.handle.net/10362/15405.
Full textAbstract:
Theropods form a highly successful and morphologically diversified group of dinosaurs that gave rise to birds. They include most, if not all, carnivorous dinosaurs, yet many theropod clades were secondarily adapted to piscivory, omnivory and herbivory, and theropods show a large array of skull and dentition morphologies. This work aims to investigate aspects of the evolution of theropod dinosaurs by analyzing in detail both the anatomy and ontogeny of teeth and quadrates in non-avian theropods, and by studying embryonic and adult material of a new species of theropod.
A standardized list of terms and notations for each anatomical entity of the tooth, quadrate, and maxilla is here proposed with the goal of facilitating descriptions of these important cranial and dental elements. The distribution of thirty dental characters among 113 theropod taxa is investigated, and a list of diagnostic dental characters is proposed. As an example, four isolated theropod teeth from the Lourinhã Formation (Kimmeridgian‒Tithonian) of Portugal are described and identified based on a cladistic analysis performed on a data matrix of 141 dentition-based characters coded in 60 taxa. Two shed teeth are referred to an abelisaurid, providing the first record of Abelisauridae in the Jurassic of Laurasia and the one of the oldest records of this clade in the world, suggesting a possible radiation of Abelisauridae in Europe well before the Upper Cretaceous. The consensus tree resulting from this phylogenetic analysis, the most extensive on theropod teeth, indicates that theropod teeth provide reliable data for identification at approximately family level, and this method will help identifying theropod teeth with more confidence. A detailed description of the dentition of Megalosauridae is also provided, and a discriminant analysis performed on a dataset of numerical data collected on the teeth of 62 theropod taxa reveals that megalosaurid teeth are hardly distinguishable from other theropod clades with ziphodont dentition. This study highlights the importance of detailing anatomical descriptions and providing additional morphometric data on teeth with the purpose of helping to identify isolated theropod teeth.
In order to evaluate the phylogenetic potential and investigate the evolutionary transformations of the quadrate, a phylogenetic morphometric analysis as well as a cladistic analysis using 98 discrete quadrate related characters were conducted. The quadrate morphology by its own provides a wealth of data with strong phylogenetic signal, and the phylogenetic morphometric analysis reveals two main morphotypes of the mandibular articulation of the quadrate linked to function. As an example, six isolated quadrates from the Kem Kem beds (Cenomanian) of Morocco are determined to be from juvenile and adult individuals of Spinosaurinae based on phylogenetic, morphometric, and phylogenetic morphometric analyses. Morphofunctional analysis of the spinosaurid mandibular articulation has shown that the posterior parts of the two mandibular rami displaced laterally when the jaw was depressed due to a mediolaterally oriented intercondylar sulcus of the quadrate. Such lateral movement of the mandibular ramus was possible due to a movable mandibular symphysis in spinosaurids, allowing the pharynx to be widened.
A new species of theropod from the Lourinhã Formation of Portugal, Torvosaurus gurneyi, is erected based on a right maxilla and an incomplete caudal centrum. This taxon supports the mechanism of vicariance that occurred in the Iberian Meseta during the Late Jurassic when the proto-Atlantic was already well formed. A theropod clutch containing several crushed eggs and embryonic material is also assigned to this new species of Torvosaurus. Investigation on the maxilla ontogeny in basal tetanurans reveals that crown denticles, elongation of the anterior ramus, and fusion of interdental plates appear at a posthatchling stage. On the other hand, maxillary pneumaticity is already present at an embryonic stage in non-avian theropods.Fundação para a Ciência e a Tecnologia (FCT) - scholarship SFRH/BD/62979/2009