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Conti, S., Tschopp E., Sala G., & Mateus O. (2021).  Multibody simulations of diplodocid tail motion. Annual conference of the European Association of Vertebrate Palaeontologists. , 5th-9th July : European Association of Vertebrate Palaeontologistsconti_et_al_2021_diplodocid_tail._eavp_abstract.pdf
Conti, S., Tschopp E., Mateus O., Zanoni A., Masarati P., & Sala G. (2022).  Multibody analysis and soft tissue strength refute supersonic dinosaur tail. 12(1), 19245., 2022 Abstractconti_et_al_2022._multibody_analysis_and_soft_tissue_strength_refute_supersonic_dinosaur_tail.pdfWebsite

Sauropod dinosaurs are well known for their massive sizes and long necks and tails. Among sauropods, flagellicaudatan dinosaurs are characterized by extreme tail elongation, which has led to hypotheses regarding tail function, often compared to a whip. Here, we analyse the dynamics of motion of a 3D model of an apatosaurine flagellicaudatan tail using multibody simulation and quantify the stress-bearing capabilities of the associated soft tissues. Such an elongated and slender structure would allow achieving tip velocities in the order of 30 m/s, or 100 km/h, far slower than the speed of sound, due to the combined effect of friction of the musculature and articulations, as well as aerodynamic drag. The material properties of the skin, tendons, and ligaments also support such evidence, proving that in life, the tail would not have withstood the stresses imposed by travelling at the speed of sound, irrespective of the conjectural ‘popper’, a hypothetical soft tissue structure analogue to the terminal portion of a bullwhip able to surpass the speed of sound.

Polcyn, M. W., Jacobs L. L., Schulp A. S., & Mateus O. (2007).  The mosasaurs of Angola. Second Mosasaur Meeting. 21., Hays, Kansas: Sternberg Museum Abstract

Although occurrences of marine reptiles have been previously reported from Angola, with the exception of two Turonian taxa, these reports were based largely on isolated teeth. Fieldwork in 2005 and 2006 yielded well-preserved remains of marine reptiles including plesiosaurs, turtles, and mosasaurs. The mosasaurs discussed here were recovered from two field areas: Turonian sediments at Iembe along the north coast and Maastrichtian sediments at Bentiaba on the south coast. The Turonian section near Iembe produced at least two new specimens of Angolasaurus bocagei and one fragmentary specimen of Tylosaurus iembeensis. One of the Angolasaurus specimens is represented by a well preserved, complete and articulated skull and partial postcrania, including portions of the forelimbs and pectoral girdle. The preservation of material from the Bentiaba locality is remarkable due to the grain support of the entombing sandstone, which preserves fine anatomical details with little apparent crushing, and in the number of articulated, semi-articulated, and associated skeletons. Identifications from the field and preliminary preparation show the Bentiaba mosasaur fauna is represented by at least five genera including Mosasaurus, Prognathodon, Globidens, Plioplatecarpus and Halisaurus. Collectively, these new specimens greatly expand our knowledge of the anatomy and systematics of Angolan mosasaurs.

Polcyn, M. W., Jacobs L. L., Schulp A. S., & Mateus O. (2007).  The mosasaurs of Angola. (Sternberg, Museum, Ed.).Second Mosasaur Meeting. 21., Hays, Kansas Abstract
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Polcyn, M. W., Jacobs L. L., Schulp A. S., & Mateus O. (2007).  The mosasaurs of Angola. Second Mosasaur Meeting. 21–21., Hays, Kansas Abstract
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Polcyn, M. J., Jacobs L. L., Schulp A. S., & Mateus O. (2007).  Morphology and systematic position of Angolasaurus bocagei and the evolution of the braincase in Plioplatecarpine mosasaurs. Second Mosasaur Meeting. , May 3-6, 2007, Sternberg Museum, Hays, Kansaspolcyn_et_al_2007_angolosaurus_mosasaurmeetingabstracts.pdf
Polcyn, M. W., Jacobs L. L., Schulp A. S., & Mateus O. (2007).  Morphology and systematic position of Angolasaurus bocagei and the evolution of the braincase in Plioplatecarpine mosasaurs. (Sternberg, Museum, Ed.).Second Mosasaur Meeting. 20., Hays, Kansas Abstract
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Polcyn, M. W., Jacobs L. L., Schulp A. S., & Mateus O. (2007).  Morphology and systematic position of Angolasaurus bocagei and the evolution of the braincase in Plioplatecarpine mosasaurs. Second Mosasaur Meeting. 20–20., Hays, Kansas Abstract
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Hendrickx, C., Bell P. R., Pittman M., Milner A. R. C., Cuesta E., O'Connor J., Loewen M., Currie P. J., Mateus O., Kaye T. G., & Delcourt R. (2022).  Morphology and distribution of scales, dermal ossifications, and other non-feather integumentary structures in non-avialan theropod dinosaurs. Biological Reviews. , Number n/a Abstracthendrickxetal.2021.morphologyanddistributionofscales.pdfWebsite

ABSTRACT Modern birds are typified by the presence of feathers, complex evolutionary innovations that were already widespread in the group of theropod dinosaurs (Maniraptoriformes) that include crown Aves. Squamous or scaly reptilian-like skin is, however, considered the plesiomorphic condition for theropods and dinosaurs more broadly. Here, we review the morphology and distribution of non-feathered integumentary structures in non-avialan theropods, covering squamous skin and naked skin as well as dermal ossifications. The integumentary record of non-averostran theropods is limited to tracks, which ubiquitously show a covering of tiny reticulate scales on the plantar surface of the pes. This is consistent also with younger averostran body fossils, which confirm an arthral arrangement of the digital pads. Among averostrans, squamous skin is confirmed in Ceratosauria (Carnotaurus), Allosauroidea (Allosaurus, Concavenator, Lourinhanosaurus), Compsognathidae (Juravenator), and Tyrannosauroidea (Santanaraptor, Albertosaurus, Daspletosaurus, Gorgosaurus, Tarbosaurus, Tyrannosaurus), whereas dermal ossifications consisting of sagittate and mosaic osteoderms are restricted to Ceratosaurus. Naked, non-scale bearing skin is found in the contentious tetanuran Sciurumimus, ornithomimosaurians (Ornithomimus) and possibly tyrannosauroids (Santanaraptor), and also on the patagia of scansoriopterygids (Ambopteryx, Yi). Scales are surprisingly conservative among non-avialan theropods compared to some dinosaurian groups (e.g. hadrosaurids); however, the limited preservation of tegument on most specimens hinders further interrogation. Scale patterns vary among and/or within body regions in Carnotaurus, Concavenator and Juravenator, and include polarised, snake-like ventral scales on the tail of the latter two genera. Unusual but more uniformly distributed patterning also occurs in Tyrannosaurus, whereas feature scales are present only in Albertosaurus and Carnotaurus. Few theropods currently show compelling evidence for the co-occurrence of scales and feathers (e.g. Juravenator, Sinornithosaurus), although reticulate scales were probably retained on the mani and pedes of many theropods with a heavy plumage. Feathers and filamentous structures appear to have replaced widespread scaly integuments in maniraptorans. Theropod skin, and that of dinosaurs more broadly, remains a virtually untapped area of study and the appropriation of commonly used techniques in other palaeontological fields to the study of skin holds great promise for future insights into the biology, taphonomy and relationships of these extinct animals.

Hendrickx, C., Mateus O., & Buffetaut E. (2016).  Morphofunctional Analysis of the Quadrate of Spinosauridae (Dinosauria: Theropoda) and the Presence of Spinosaurus and a Second Spinosaurine Taxon in the Cenomanian of North Africa.. PLoS ONE. 11, e0144695., 01, Number 1: Public Library of Science Abstracthendrickx_et_al_2016_morphofunctional_analysis_of_the_quadrate_of_spinosauridae_dinosauria.pdfWebsite

Six quadrate bones, of which two almost certainly come from the Kem Kem beds (Cenomanian, Upper Cretaceous) of south-eastern Morocco, are determined to be from juvenile and adult individuals of Spinosaurinae based on phylogenetic, geometric morphometric, and phylogenetic morphometric analyses. Their morphology indicates two morphotypes evidencing the presence of two spinosaurine taxa ascribed to Spinosaurus aegyptiacus and? Sigilmassasaurus brevicollis in the Cenomanian of North Africa, casting doubt on the accuracy of some recent skeletal reconstructions which may be based on elements from several distinct species. Morphofunctional analysis of the mandibular articulation of the quadrate has shown that the jaw mechanics was peculiar in Spinosauridae. In mature spinosaurids, the posterior parts of the two mandibular rami displaced laterally when the jaw was depressed due to a lateromedially 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. Similar jaw mechanics also occur in some pterosaurs and living pelecanids which are both adapted to capture and swallow large prey items. Spinosauridae, which were engaged, at least partially, in a piscivorous lifestyle, were able to consume large fish and may have occasionally fed on other prey such as pterosaurs and juvenile dinosaurs.

Hendrickx, C., Mateus O., & Buffetaut E. (2016).  Morphofunctional Analysis of the Quadrate of Spinosauridae (Dinosauria: Theropoda) and the Presence of Spinosaurus and a Second Spinosaurine Taxon in the Cenomanian of North Africa.. PLoS ONE. 11, e0144695., 01, Number 1: Public Library of Science AbstractWebsite

Six quadrate bones, of which two almost certainly come from the Kem Kem beds (Cenomanian, Upper Cretaceous) of south-eastern Morocco, are determined to be from juvenile and adult individuals of Spinosaurinae based on phylogenetic, geometric morphometric, and phylogenetic morphometric analyses. Their morphology indicates two morphotypes evidencing the presence of two spinosaurine taxa ascribed to Spinosaurus aegyptiacus and? Sigilmassasaurus brevicollis in the Cenomanian of North Africa, casting doubt on the accuracy of some recent skeletal reconstructions which may be based on elements from several distinct species. Morphofunctional analysis of the mandibular articulation of the quadrate has shown that the jaw mechanics was peculiar in Spinosauridae. In mature spinosaurids, the posterior parts of the two mandibular rami displaced laterally when the jaw was depressed due to a lateromedially 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. Similar jaw mechanics also occur in some pterosaurs and living pelecanids which are both adapted to capture and swallow large prey items. Spinosauridae, which were engaged, at least partially, in a piscivorous lifestyle, were able to consume large fish and may have occasionally fed on other prey such as pterosaurs and juvenile dinosaurs.

Mateus, O. (1999).  Monofilia dos dinossauros e Origem das Aves: Serão as aves dinossauros?. (Spea- Sociedade Portuguesa para o Estudo das Aves, P, P Catry, F Moreira, Ed.).Actas do II Congresso de Ornitologia. 184-185., Lisboa Abstract
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Mateus, O. (1999).  Monofilia dos dinossauros e Origem das Aves: Serão as aves dinossauros?. Actas do II Congresso de Ornitologia. 184–185., Lisboa Abstract
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Mateus, O. (1999).  Monofilia dos dinossauros e Origem das Aves: Serão as aves dinossauros?. (P, P Catry, F Moreira, Ed.).Actas do II Congresso de Ornitologia. 184-185., Lisboa: SPEA- Sociedade Portuguesa para o Estudo das Aves Abstract
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Guillaume, A. R. D., Moreno-Azanza M., & Mateus O. (2018).  Microvertebrates from the Lourinhã Formation (Late Jurassic, Portugal). 1st Palaeontological Virtual Congress. online. Abstractguillaume-et-al_pvc2018_abstract.pdf

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Pereira, B. C., Benton M. J., Ruta M., & Mateus O. (2015).  Mesozoic echinoid diversity in Portugal: Investigating fossil record quality and environmental constraints on a regional scale. Palaeogeography, Palaeoclimatology, Palaeoecology. 424, 132 - 146. Abstractpereira_e_al_2015_mesozoic_echinoids_portugal.pdfWebsite

Abstract Several analyses of diversity through geological time use global, synoptic databases, and this practice often makes it difficult to distinguish true signals in changing diversity from regional-scale sampling and/or geological artefacts. Here we investigate how echinoid diversity changed through the Mesozoic of the Lusitanian basin in Portugal based on a comprehensive, revised database, and seek to distinguish biological signal from geological or environmental constraints. The observed diversity pattern is far from having a defined trend, showing many fluctuations that appear to be linked with gaps in the geological record. This study revealed that, independently of the method used, whether correlation tests or model fitting, the diversity signal is not completely explained by the studied sampling proxies. Among the different proxies, marine facies variation in combination with outcrop area best explains the palaeodiversity curve.

Pereira, B. C., Benton M. J., Ruta M., & Mateus O. (2015).  Mesozoic echinoid diversity in Portugal: Investigating fossil record quality and environmental constraints on a regional scale. Palaeogeography, Palaeoclimatology, Palaeoecology. 424, 132-146. Abstract
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Conti, S., Mateus O., & Sala G. (2021).  Mechanical characterization of tibial bone material of an ostrich. Rossi V., Fanti F., Barbieri G., Cavalazzi B. & Scarponi D. (Editors) 2021. Paleodays 2021. Abstract Book del XXI Convegno della Società Paleontologica Italiana, live virtual edition: 127 pp.. , 15-17 June, Bologna (Italy): University of Bolognaconti_et_al_2021_ostrich_bone.pdf
Polcyn, M. J., Jacobs L. L., Mateus O., Schulp A. S., Strganac C., Araújo R., Graf J. F., Vineyard D., & Myers T. S. (2013).  A marine vertebrate assemblage from the Campanian-Maastrichtian boundary at Bentiaba, Angola. Geological Society of America Abstracts with Programs. Vol. 45, No. 7, p.0. polcyn_et_al_2013_abstract__a_marine_vertebrate_assemblage_from_the_campanian-maastrichtian_boundary_at_bentiaba_angola_2013__gsa_27-30_october_2013.pdf
Araujo, R., Castanhinha R., & Mateus O. (2008).  Major trends in the evolution of teeth and mandibles in ornithopod dinosaurs. Livro de Resumos de Tercer Congreso Latinoamericano de Paleontología de Vertebrados. 18., Neuquén, Argentina Abstractaraujo_et_al._2008._major_trends_in_the_evolution_of_teeth_and_mandibles_in_ornithopod_dinosaurs.pdf

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Araujo, R., Castanhinha R., & Mateus O. (2008).  Major trends in the evolution of teeth and mandibles in ornithopod dinosaurs. Livro de Resumos de Tercer Congreso Latinoamericano de Paleontología de Vertebrados. 18., Neuquén, Argentina Abstract
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Araujo, R., Castanhinha R., & Mateus O. (2008).  Major trends in the evolution of teeth and mandibles in ornithopod dinosaurs. Livro de Resumos de Tercer Congreso Latinoamericano de Paleontología de Vertebrados. 18–18., Neuquén, Argentina Abstract
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