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Leal, S., Mateus O., Tomás C., & Dionisio A. (2014).  Degradation processes and consolidation of Late Jurassic sandstone dinosaur tracks in museum environment (Museum of Lourinhã, Portugal). EGU General Assembly 2014 - Geophysical Research Abstracts. Vol. 16, EGU2014-9026-1, 2014.leal_et_al_2014_tracks_lab_egu2014-9026-1.pdf
Leal, A. A., Dion{\'ısio A., Braga M. A. S., & Mateus O. (2016).  The long term preservation of Late Jurassic sandstone dinosaur footprints in a museum environment. International Journal of Conservation Science. 7, 627-646. AbstractWebsite

This study focuses on the assessment of the degradation processes occurring in three sandstone infills of fossilized Late Jurassic ornithopod tridactyl footprints, found in 2001 in a coastline cliff in Porto das Barcas (Lourinhã, Portugal) and exhibited in a museum display since 2004. These dinosaur footprints present nowadays severe decay phenomena compromising their physical integrity and are leading gradually to their loss of value. The deterioration patterns were recorded, a map of their distribution was prepared and several samples were collected both in the dinosaur footprints and in the coastline cliff. Different analytical procedures were applied such as XRD, FTIR, FESEM and Ion Chromatography. A microclimatic survey was also performed and air temperature and relative humidity was measured during eight months both indoor and also outdoor. The decay patterns observed are a combination intrinsic and extrinsic factors the stone material, namely swelling of clay minerals in the rock matrix (smectite and chlorite-smectite mixed-layer), presence of salts (mainly chlorides), application of past conservation treatments (poly(vinyl) acetate and epoxy resins) and with the museum’s indoor thermohygrometric conditions (mainly non-stable hygrometric conditions). This scientific knowledge is therefore essential to the sustainable preservation of this paleontological heritage.

Lategano, F., Conti S., Costa F., Mateus O., & Lozar F. (2022).  Fighter or bluffer: comparison of bending and compression in models of the caudal spines of dacentrurine and stegosaurine stegosaurs. XIX Annual Conference of the European Association of Vertebrate Paleontologists. 113. Abstract
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Lallensack,  J. N., Klein  H., Milàn  J., Wings  O., Mateus  O., & Clemmensen  L. B. (2017).  Sauropodomorph dinosaur trackways from the Fleming Fjord Formation of East Greenland: evidence for Late Triassic sauropods. AbstractWebsite
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Lallensack, J. N., Klein H., Milàn J., Wings O., Mateus O., & Clemmensen L. B. (2017).  Sauropodomorph dinosaur trackways from the Fleming Fjord Formation of East Greenland: Evidence for Late Triassic sauropods. Acta Palaeontologica Polonica. 62(4), 833-843. Abstractlallensack_et_al_2017_-_sauropodomorph_tracks_greenland.pdf

The Late Triassic (Norian–early Rhaetian) Fleming Fjord Formation of central East Greenland preserves a diverse fossil fauna, including both body and trace fossils. Trackways of large quadrupedal archosaurs, although already reported in 1994 and mentioned in subsequent publications, are here described and figured in detail for the first time, based on photogrammetric data collected during fieldwork in 2012. Two trackways can be referred to Eosauropus, while a third, bipedal trackway may be referred to Evazoum, both of which have been considered to represent sauropodomorph dinosaur tracks. Both the Evazoum and the Eosauropus trackways are distinctly larger than other trackways referred to the respective ichnogenera. The trackmaker of the best preserved Eosauropus trackway is constrained using a synapomorphy-based approach. The quadrupedal posture, the entaxonic pes structure, and five weight-bearing digits indicate a derived sauropodiform trackmaker. Other features exhibited by the tracks, including the semi-digitigrade pes and the laterally deflected unguals, are commonly considered synapomorphies of more exclusive clades within Sauropoda. The present trackway documents an early acquisition of a eusauropod-like pes anatomy while retaining a well-developed claw on pedal digit IV, which is reduced in eusauropods. Although unequivocal evidence for sauropod dinosaurs is no older than the Early Jurassic, the present trackway provides evidence for a possible Triassic origin of the group.

Lallensack, J. N., Klein H., Milàn J., Wings O., Mateus O., & Clemmensen L. B. (2017).  Sauropodomorph dinosaur trackways from the Fleming Fjord Formation of East Greenland: evidence for Late Triassic sauropods. Acta Palaeontologica Polonica. 62, 833–843., Number 4 Abstract
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Kullberg, J. C., Rocha R. B., Soares A. F., Rey J., Terrinha P., Azerêdo A. C., Callapez P., Duarte, L.V., Kullberg M. C., Martins L., Miranda J. R., Alves C., Mata J., Madeira J., Mateus O., Moreira M., & Nogueira C. R. (2013).  A Bacia Lusitaniana: Estratigrafia, Paleogeografia e Tectónica. (Dias, R. Araújo, A, Terrinha, P. and Kullberg, J. C., Ed.).Geologia de Portugal no contexto da Ibéria. Volume II. 195-350., Lisboa: Escolar Editorakullberg_et_al_2013_a_bacia_lusitaniana.pdf
Klein, H., Milàn J., Clemmensen L. B., Frobøse N., Mateus O., Klein N., Adolfssen J. S., Estrup E. J., & Wings O. (2016).  Archosaur footprints (cf. Brachychirotherium) with unusual morphology from the Upper Triassic Fleming Fjord Formation (Norian–Rhaetian) of East Greenland. Geological Society, London, Special Publications. 434(1), 71-85. Abstractklein_et_al_2015_archosaur_footprints_cf._brachychirotherium_with_unusual.pdfWebsite

The Ørsted Dal Member of the Upper Triassic Fleming Fjord Formation in East Greenland is well known for its rich vertebrate fauna, represented by numerous specimens of both body and ichnofossils. In particular, the footprints of theropod dinosaurs have been described. Recently, an international expedition discovered several slabs with 100 small chirotheriid pes and manus imprints (pes length 4–4.5 cm) in siliciclastic deposits of this unit. They show strong similarities with Brachychirotherium, a characteristic Upper Triassic ichnogenus with a global distribution. A peculiar feature in the Fleming Fjord specimens is the lack of a fifth digit, even in more deeply impressed imprints. Therefore, the specimens are assigned here tentatively to cf. Brachychirotherium. Possibly, this characteristic is related to the extremely small size and early ontogenetic stage of the trackmaker. The record from Greenland is the first evidence of this morphotype from the Fleming Fjord Formation. Candidate trackmakers are crocodylian stem group archosaurs; however, a distinct correlation with known osteological taxa from this unit is not currently possible. While the occurrence of sauropodomorph plateosaurs in the bone record links the Greenland assemblage more closer to that from the Germanic Basin of central Europe, here the described footprints suggest a Pangaea-wide exchange.Supplementary material: Three-dimensional model of cf. Brachychirotherium pes–manus set (from MGUH 31233b) from the Upper Triassic Fleming Fjord Formation (Norian–Rhaetian) of East Greenland as pdf, ply and jpg files (3D model created by Oliver Wings; photographs taken by Jesper Milàn) is available at https://doi.org/10.6084/m9.figshare.c.2133546

Klein, H., Milàn J., Clemmensen L. B., Frobøse N., Mateus O., Klein N., Adolfssen J. S., Estrup E. J., & Wings O. (2015).  Archosaur footprints (cf. Brachychirotherium) with unusual morphology from the Upper Triassic Fleming Fjord Formation (Norian–Rhaetian) of East Greenland. Geological Society, London, Special Publications. 434, AbstractWebsite

The Ørsted Dal Member of the Upper Triassic Fleming Fjord Formation in East Greenland is well known for its rich vertebrate fauna, represented by numerous specimens of both body and ichnofossils. In particular, the footprints of theropod dinosaurs have been described. Recently, an international expedition discovered several slabs with 100 small chirotheriid pes and manus imprints (pes length 4–4.5 cm) in siliciclastic deposits of this unit. They show strong similarities with Brachychirotherium, a characteristic Upper Triassic ichnogenus with a global distribution. A peculiar feature in the Fleming Fjord specimens is the lack of a fifth digit, even in more deeply impressed imprints. Therefore, the specimens are assigned here tentatively to cf. Brachychirotherium. Possibly, this characteristic is related to the extremely small size and early ontogenetic stage of the trackmaker. The record from Greenland is the first evidence of this morphotype from the Fleming Fjord Formation. Candidate trackmakers are crocodylian stem group archosaurs; however, a distinct correlation with known osteological taxa from this unit is not currently possible. While the occurrence of sauropodomorph plateosaurs in the bone record links the Greenland assemblage more closer to that from the Germanic Basin of central Europe, here the described footprints suggest a Pangaea-wide exchange.Supplementary material: Three-dimensional model of cf. Brachychirotherium pes–manus set (from MGUH 31233b) from the Upper Triassic Fleming Fjord Formation (Norian–Rhaetian) of East Greenland as pdf, ply and jpg files (3D model created by Oliver Wings; photographs taken by Jesper Milàn) is available at https://doi.org/10.6084/m9.figshare.c.2133546

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Jésus, V. J. P., Mateus O., Milàn J., & Clemmensen L. B. (2022).  First occurrence of a frog-like batrachian (Amphibia) in the Late Triassic Fleming Fjord Group, central East Greenland. Bulletin of the Geological Society of Denmark. 70, 117–130. Abstractbull70-117-130.pdfWebsite

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Jacobs, L. L., Polcyn M. J., Mateus O., Schulp A. S., Gon?alves A. O., & Morais M. L. (2016).  Post-Gondwana Africa and the vertebrate history of the Angolan Atlantic Coast. Memoirs of Museum Victoria. 74, 343-362. Abstract
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Jacobs, L. L., Polcyn M. J., Mateus O., Schulp A. S., & Neto A. (2009).  The Cretaceous Skeleton Coast of Angola. Journal of Vertebrate Paleontology. 29, 121–121., Number 3 Abstract
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Jacobs, L., Polcyn M., Mateus O., Scott M., Graf J., Kappelman J., Jacobs B., Schulp A., Morais M., & Goncalves O. (2014).  Cenozoic vertebrates of coastal Angola. Journal of Vertebrate Paleontology, Program and Abstracts, 2014. 153.jacobs_et_al._2014_cenozoic_vertebrates_of_coastal_angola.pdf
Jacobs, L. L., Polcyn M. J., Mateus O., Schulp A. S., Gonçalves A. O., & Morais M. L. (2016).  Post-Gondwana Africa and the vertebrate history of the Angolan Atlantic Coast. Memoirs of Museum Victoria. 74, 343–362. Abstractjacobs_et_al_2016_post-gondwana_africa_and_the_vertebrate_history_of_the_angolan_atlantic_coast_343-362_mmv74_jacobs_4_web.pdf

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Jacobs, L.  L., Sousa N., Goncalves A.  O., Mateus O., Polcyn M.  J., & Schulp A.  S. (2020).  Projecto PaleoAngola: Geoheritage and Conservation Paleobiology as Science for Development in Angola. AGU Fall Meeting Abstracts. 2020, SY048-05. Abstractprojecto_paleoangola__geoheritage.pdf

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Jacobs, L., Polcyn M., Araújo R., Strganac C., & Mateus O. (2010).  Physical drivers of evolution and the history of the marine tetrapod fauna of Angola. Annual Meeting of the Society of Vertebrate Paleontology. 110A., Jan Abstractjacobs_et_al_mateus_2010_physical_drivers_marine_tetrapod_fauna_of_angola_svp10abstracts.pdf

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Jacobs, L. L., Mateus O., Polcyn M. J., Schulp A. S., Antunes M. T., Morais M. L., & da Silva Tavares T. (2006).  The occurrence and geological setting of Cretaceous dinosaurs, mosasaurs, plesiosaurs, and turtles from Angola. JOURNAL-PALEONTOLOGICAL SOCIETY OF KOREA. 22, 91–91., Number 1 Abstract
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Jacobs, L. L., Polcyn M. J., Mateus O. \á\}vio, Schulp A. S., Gon\{\c c\}alves A. \ó\}nio O., & Morais M. L. (2016).  Post-Gondwana Africa and the vertebrate history of the Angolan Atlantic Coast. Memoirs of Museum Victoria. 74, 343\–\}362. Abstract
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Jacobs, L. L., Morais M. L., Schulp A. S., Mateus O., & Polcyn M. J. (2006).  Systematic Position and Geological Context of Angolasaurus (Mosasauridae) and a New Sea Turtle from the Cretaceous of Angola. Journal of Vertebrate Paleontology, 26 (Suppl. To 3). 81. Abstract
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Jacobs, L., Polcyn M., Mateus O., Schulp A. S., & Neto A. B. (2009).  The Cretaceous Skeleton Coast of Angola. Journal of Vertebrate Paleontology. 29, 121A., Jan Abstractjacobs_et_al_2009cretaceousskeletoncoas.pdfWebsite

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Jacobs, L. L., Mateus O., Polcyn M. J., Schulp A. S., Scotese C. R., Goswami A., Ferguson K. M., Robbins J. A., Vineyard D. P., & Neto A. B. (2009).  Cretaceous paleogeography, paleoclimatology, and amniote biogeography of the low and mid-latitude South Atlantic Ocean. Bulletin de la Societe Geologique de France. 180, 333-341., Number 4 Abstract
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Jacobs, L. L., Polcyn M. J., Mateus O., Schulp A., Ferguson K., Scotese C., Jacobs B. F., Strganac C., Vineyard D., Myers T. S., & Morais M. L. (2010).  Tectonic Drift, Climate, and Paleoenvironment of Angola Since the Cretaceous. AGU Fall Meeting Abstracts, 1:. 02., Jan Abstractjacobs_polcyn_mateus_et_al_2010_tectonic_drift_climate_and_paleoenvironment_of_angola_since_the_cretaceous.pdf

Africa is the only continent that now straddles arid zones located beneath the descending limbs of both the northern and southern Hadley cells, and it has done so since it became a distinct continent in the Early Cretaceous. Since that time, Africa has drifted tectonically some 12 degrees north and rotated approximately 45 degrees counterclockwise. This changing latitudinal setting and position of the landmass under the relatively stable Hadley Cells is manifested as southward migration of climatic zones over the past 132 million years. Data from kerogen, X-ray diffraction analysis of sedimentary matrix, carbon isotopes from shell samples and tooth enamel,new 40Ar/39Ar radiometric dates, pollen and plant macrofossils, and fossil vertebrates indicate a productive upwelling system adjacent to a coastal desert since the opening of the South Atlantic Ocean; however, the position of the coastal desert has migrated southward as Africa drifted north, resulting in today's Skeleton Coast and Benguela Current. This migration has had a profound effect on the placement of the West African coast relative to areas of high marine productivity and resulting extensive hydrocarbon deposits, on the placement of arid zones relative to the continent especially the Skeleton Coast desert, on the climatic history of the Congo Basin (which shows a Late Cretaceous decrease in aridity based on the relative abundance of analcime in the Samba core), and in reducing the southern temperate region of Africa from 17% of continental area during the Cretaceous to 2% today. We show here that these related geographic and environmental changes drove ecological and evolutionary adjustments in southern African floras and faunas, specifically with respect to the distribution of anthropoid primates, the occurrence of modern relicts such as the gnetalean Welwitschia mirabilis, endemism as in the case of ice plants, and mammalian adaption to an open environment as in springhares. Africa's tectonic drift through climate zones has been a first-order environmental determinant since the Early Cretaceous.

Jacobs, L., Polcyn M., Mateus O., Schulp, & Neto A. (2009).  The Cretaceous Skeleton Coast of Angola. Journal of Vertebrate Paleontology. 29, 121., Number 3 Abstract
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Jacobs, L. L., Myers T. S., Goncalves A. O., Graf J. F., Jacobs B. F., KAPPELMAN J. W., Mateus O., Polcyn M. J., RASBURY E. T., & Vineyard D. P. (2013).  Cabinda revisited: age and environment of new Cenozoic vertebrate fossils from northern Angola. Geological Society of America Abstracts with Programs. Vol. 45, No. 7, p.0.
Jacobs, L. L., Polcyn M. J., Mateus O., & Schulp A. S. (2023).  Deep time conservation paleobiology of the Atlantic jigsaw puzzle and the future of the southwestern Angolan coast. Bulletin of the Florida Museum of Natural History. 60(2), 90.: In: Abstracts of the 2nd Conservation Paleobiology Symposium. https://doi … Abstractjacobs_et_al_2023_jigsaw.pdf

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Jacobs, L. L., Mateus O., Polcyn M. J., Schulp A. S., Scotese C. R., Goswami A., Ferguson K. M., Robbins J. A., Vineyard D. P., & Neto A. B. (2009).  Cretaceous paleogeography, paleoclimatology, and amniote biogeography of the low and mid-latitude South Atlantic Ocean. BULLETIN DE LA SOCIETE GEOLOGIQUE DE FRANCE. 180, 333-341., Jan: Univ Agostinho Neto, Univ Nova Lisboa, So Methodist Univ, Univ Texas Arlington, Museu Lourinha, Nat Hist Museum Abstractjacobs_mateus_et_al_2009_cretaceous_paleogeography_paleoclimatology_and_amniote_biogeography_of_the_south_atlantic_ocean_angola_africa_currents.pdf

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Jacobs, L. L., Schröder S., de Sousa N., Dixon R., Fiordalisi E., Marechal A., Mateus O., Nsungani P. C., Polcyn M. J., do Pereira G. C. R., Rochelle-Bates N., Schulp A. S., Scotese C. R., Sharp I., Silvano C. G., Swart R., & Vineyard D. P. (2024).  The Atlantic jigsaw puzzle and the geoheritage of Angola. Geological Society, London, Special Publications. 543, SP543-2022-301., Number 1 AbstractWebsite

The jigsaw-puzzle fit of South America and Africa is an icon of plate tectonics and continental drift. Fieldwork in Angola since 2002 allows the correlation of onshore outcrops and offshore geophysical and well-core data in the context of rift, sag, salt, and post-salt drift phases of the opening of the central South Atlantic. These outcrops, ranging in age from >130 Ma to <71 Ma, record Early Cretaceous outpouring of the Etendeka-Paraná Large Igneous Province (Bero Volcanic Complex) and rifting, followed by continental carbonate and siliciclastic deposition (Tumbalunda Formation) during the sagging of the nascent central South Atlantic basin. By the Aptian, evaporation of sea water resulted in thick salt deposits (Bambata Formation), terminated by sea floor spreading. The Equatorial Atlantic Gateway began opening by the early Late Cretaceous (100 Ma) and allowed flow of currents between the North and South Atlantic, creating environmental conditions that heralded the introduction of marine reptiles. These dramatic outcrops are a unique element of geoheritage because they arguably comprise the most complete terrestrially exposed geological record of the puzzle-like icon of continental drift.

Jacobs, L. L., Mateus O., Polcyn M. J., Schulp A. S., Antunes M. T., Morais M. L., & da Silva Tavares T. (2006).  The occurrence and geological setting of Cretaceous dinosaurs, mosasaurs, plesiosaurs, and turtles from Angola. Paleont. Soc. Korea. 22(1), 91-110. Abstractjacobs_mateus-et_al_2006_angola.pdf

Vertebrate-bearing fossiliferous outcrops of Cretaceous age in sub-Saharan Africa are rare because of younger superficial deposits, vegetation cover, and the widespread occurrence of Precambrian metamorphic plateau basement comprising much of the continent. However, one area of extensive marine and nonmarine
Cretaceous exposures is found between the plateau and the coast in Angola. The Angolan margin was formed in conjunction with the breakup of Gondwana and subsequent growth of the South Atlantic. Cretaceous deposits are constrained in age by the emplacement of oceanic crust, which began no later than magnetozone M3
(approximately 128 Ma, Barremian). Shallow marine facies are exposed in sea cliffs but equivalent facies become increasingly terrestrial inland. Few vertebrate fossils have been described from Angola aside from sharks.
Notable exceptions are the late Turonian mosasaurs Angolasaurus bocagei and Tylosaurus iembeensis from northern Angola. Those taxa are significant because they are among the earliest derived mosasaurs. Recent field work led to the discovery of a new skull of Angolasaursus as well as sharks, fish, plesiosaurs, the skull of a new taxon of turtle, additional mosasaurs, and the articulated forelimb of a sauropod dinosaur, the first reported dinosaur from Angola. In southern Angola, marine sediments spanning the Cretaceous-Paleogene boundary are found.

Jacobs, L. L., Mateus O., Polcyn M. J., Schulp A. S., Antunes M. T., Morais M. L., & Tavares T. S. (2006).  The occurrence and geological setting of Cretaceous dinosaurs, mosasaurs, plesiosaurs, and turtles from Angola. Journal of the Paleontological Society of Korea. 22, , Number 1 Abstract
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Jackson, Y. J., Economos R. C., Jacobs L. L., Mateus O., & Gonçalves A. O. (2020).  When dinosaurs walked through diamonds: constraining the age of Early Cretaceous footprints in volcanic crater sediments. 54th Annual GSA South-Central Section Meeting 2020. , Fort Worth: Geological Society of America Abstracts with Programs. Vol. 52, No. 1jackson_et_al_2020_abstract__when_dinosaurs_walked_through_diamonds__gsa.pdf
Jackson, Y., Economos R., Jacobs L., Mateus O., & Gonçalves A. O. (2021).  When Dinosaurs Walked Through Diamonds: Constraining the Age of Early Cretaceous Footprints in Volcanic Crater Sediments. SMU Journal of Undergraduate Research. 6(1), : DOI: https://doi.org/ 10.25172/jour.6.1.1 Available at: https://scholar.smu … Abstractwhen_dinosaurs_walked_through_diamonds.pdf

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Jacinto, J. J., & Mateus O. (2002).  Integration of the distribution of Hemidactylus turcicus and Tarentola mauritanica in Portugal Continental in a G.I.S. and some occasional observations. (Sociedade Portuguesa de, Herpetologia, Ed.).Livro de resumos do VII Congresso Luso-espanhol (XI Congreso Español) de Herpetologia. 127., Évora, Portugal Abstract
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Jacinto, J. J., & Mateus O. (2002).  Integration of the distribution of Hemidactylus turcicus and Tarentola mauritanica in Portugal Continental in a G.I.S. and some occasional observations. Livro de resumos do VII Congresso Luso-espanhol (XI Congreso Español) de Herpetologia. 127–127., Évora, Portugal Abstract
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Jacinto, J. J., & Mateus O. (2002).  Integration of the distribution of Hemidactylus turcicus and Tarentola mauritanica in Portugal Continental in a G.I.S. and some occasional observations. Livro de resumos do VII Congresso Luso-espanhol (XI Congreso Español de Herpetologia. 127., Évora, Portugal: Sociedade Portuguesa de Herpetologia & Associacion Herpetologica Española Abstract

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Holwerda, F., Tschopp E., & Mateus O. (2014).  Sauropod body fossils in Europe: overview and current issues. XII EAVP Meeting XII Annual Meeting of the European Association of Vertebrate Palaeontologists – Abstract Book. p.77., Torino 24-28 June 2014holwerda_et_al_2014_sauropods_europe_eavp.pdf
Hendrickx, C., Mateus O., & Araújo R. (2015).  The dentition of megalosaurid theropods. Acta Palaeontologica Polonica. 60(3), 627–642. Abstracthendrickx_et_al_2015_theropod_teeth_app.pdfWebsite

Theropod teeth are particularly abundant in the fossil record and frequently reported in the literature. Yet, the dentition of many theropods has not been described comprehensively, omitting details on the denticle shape, crown ornamentation and enamel texture. This paucity of information has been particularly striking in basal clades, thus making identification of isolated teeth difficult, and taxonomic assignments uncertain. We here provide a detailed description of the dentition of Megalosauridae, and a comparison to and distinction from superficially similar teeth of all major theropod clades. Megalosaurid dinosaurs are characterized by a mesial carina facing mesiolabially in most mesial teeth, centrally positioned carinae on both most mesial and lateral crowns, a mesial carina terminating above the cervix, and short to well-developed interdenticular sulci between distal denticles. 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 the future.

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., Araújo R., & Mateus O. (2014).  The nonavian theropod quadrate II: systematic usefulness, major trends and cladistic and phylogenetic morphometrics analyses. PeerJ PrePrints. 2, e380v2., 2014 AbstractWebsite

The skull-bone quadrate in nonavian theropods is very diverse morphologically alongside the disparity of the group as a whole. However this disparity has been underestimated for taxonomic purposes. In order to evaluate the phylogenetic potential and investigate the evolutionary transformations of the quadrate, we conducted a Catalano-Goloboff phylogenetic morphometric analysis as well as a cladistic analysis using 98 discrete quadrate related characters. The cladistic analysis provides a fully resolved tree mirroring to some degree the classification of nonavian theropods. The quadrate morphology by its own provides a wealth of data with strong phylogenetic signal and allows inference of major trends in the evolution of this bone. Important synapomorphies include: for Abelisauroidea, a lateral ramus extending to the ectocondyle; for Tetanurae, the absence of the lateral process; for Spinosauridae, a medial curvature of the ventral part of the pterygoid ramus occurring just above the mandibular articulation; for Avetheropoda, an anterior margin of the pterygoid flange formed by a roughly parabolic margin; and for Tyrannosauroidea, a semi-oval pterygoid flange shape in medial view. The Catalano-Goloboff phylogenetic morphometric analysis reveals two main morphotypes of the mandibular articulation of the quadrate linked to function. The first morphotype, characterized by an anteroposteriorly broad mandibular articulation with two ovoid/subcircular condyles roughly subequal in size, is found in Ceratosauria, Tyrannosauroidea and Oviraptorosauria. This morphotype allows a very weak displacement of the mandible laterally. The second morphotype is characterized by an elongate and anteroposteriorly narrow mandibular articulation and a long and parabolic/sigmoid ectocondyle. Present in Megalosauroidea, Carcharodontosauridae and Dromaeosauridae, this morphotype permits the lower jaw rami to be displaced laterally when the mouth opened.

Hendrickx, C., Hartman S. A., & Mateus O. \á\}vio (2015).  An overview of non-avian theropod discoveries and classification. PalArch\’\}s Journal of Vertebrate Palaeontology. 12, 1-73. Abstract
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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.

Hendrickx, C., Hartman S. A., & Mateus O. (2015).  An overview of non-avian theropod discoveries and classification. PalArch’s Journal of Vertebrate Palaeontology. 12, 1-73. AbstractWebsite

Theropods form a taxonomically and morphologically diverse group of dinosaurs that include extant birds. Inferred relationships between theropod clades are complex and have changed dramatically over the past thirty years with the emergence of cladistic techniques. Here, we present a brief historical perspective of theropod discoveries and classification, as well as an overview on the current systematics of non-avian theropods. The first scientifically recorded theropod remains dating back to the 17th and 18th centuries come from the Middle Jurassic of Oxfordshire and most likely belong to the megalosaurid Megalosaurus. The latter was the first theropod genus to be named in 1824, and subsequent theropod material found before 1850 can all be referred to megalosauroids. In the fifty years from 1856 to 1906, theropod remains were reported from all continents but Antarctica. The clade Theropoda was erected by Othniel Charles Marsh in 1881, and in its current usage corresponds to an intricate ladder-like organization of ‘family’ to ‘superfamily’ level clades. The earliest definitive theropods come from the Carnian of Argentina, and coelophysoids form the first significant theropod radiation from the Late Triassic to their extinction in the Early Jurassic. Most subsequent theropod clades such as ceratosaurs, allosauroids, tyrannosauroids, ornithomimosaurs, therizinosaurs, oviraptorosaurs, dromaeosaurids, and troodontids persisted until the end of the Cretaceous, though the megalosauroid clade did not extend into the Maastrichtian. Current debates are focused on the monophyly of deinonychosaurs, the position of dilophosaurids within coelophysoids, and megaraptorans among neovenatorids. Some recent analyses have suggested a placement of dilophosaurids outside Coelophysoidea, Megaraptora within Tyrannosauroidea, and a paraphyletic Deinonychosauria with troodontids placed more closely to avialans than dromaeosaurids.

Hendrickx, C., Aráujo R., & Mateus O. (2015).  The non-avian theropod quadrate I: Standardized terminology with an overview of the anatomy and function. PeerJ. 2015, , Number 9 Abstract
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Hendrickx, C., Hartman S. A., & Mateus O. (2015).  An overview of non-avian theropod discoveries and classification. PalArch’s Journal of Vertebrate Palaeontology. 12(1), 1-73. Abstracthendrickx_etal_2015_non_avian_theropods_pjvp12_11.pdfWebsite

Theropods form a taxonomically and morphologically diverse group of dinosaurs that include extant birds. Inferred relationships between theropod clades are complex and have changed dramatically over the past thirty years with the emergence of cladistic techniques. Here, we present a brief historical perspective of theropod discoveries and classification, as well as an overview on the current systematics of non-avian theropods. The first scientifically recorded theropod remains dating back to the 17th and 18th centuries come from the Middle Jurassic of Oxfordshire and most likely belong to the megalosaurid Megalosaurus. The latter was the first theropod genus to be named in 1824, and subsequent theropod material found before 1850 can all be referred to megalosauroids. In the fifty years from 1856 to 1906, theropod remains were reported from all continents but Antarctica. The clade Theropoda was erected by Othniel Charles Marsh in 1881, and in its current usage corresponds to an intricate ladder-like organization of ‘family’ to ‘superfamily’ level clades. The earliest definitive theropods come from the Carnian of Argentina, and coelophysoids form the first significant theropod radiation from the Late Triassic to their extinction in the Early Jurassic. Most subsequent theropod clades such as ceratosaurs, allosauroids, tyrannosauroids, ornithomimosaurs, therizinosaurs, oviraptorosaurs, dromaeosaurids, and troodontids persisted until the end of the Cretaceous, though the megalosauroid clade did not extend into the Maastrichtian. Current debates are focused on the monophyly of deinonychosaurs, the position of dilophosaurids within coelophysoids, and megaraptorans among neovenatorids. Some recent analyses have suggested a placement of dilophosaurids outside Coelophysoidea, Megaraptora within Tyrannosauroidea, and a paraphyletic Deinonychosauria with troodontids placed more closely to avialans than dromaeosaurids.

Hendrickx, C., Mateus O., Araújo R., & Choiniere J. (2019).  The distribution of dental features in non-avian theropod dinosaurs: Taxonomic potential, degree of homoplasy, and major evolutionary trends. Palaeontologia Electronica. 22(3), 1-110. Abstractthe_distribution_of_dental_features_in_non-avian_t.pdfWebsite

Isolated theropod teeth are some of the most common fossils in the dinosaur fossil record and are continually reported in the literature. Recently developed quantitative methods have improved our ability to test the affinities of isolated teeth in a repeatable framework. But in most studies, teeth are diagnosed on qualitative characters. This can be problematic because the distribution of theropod dental characters is still poorly documented, and often restricted to one lineage. To help in the identification of isolated theropod teeth, and to more rigorously evaluate their taxonomic and phylogenetic potential, we evaluated dental features in two ways. We first analyzed the distribution of 34 qualitative dental characters in a broad sample of taxa. Functional properties for each dental feature were included to assess how functional similarity generates homoplasy. We then compiled a quantitative data matrix of 145 dental characters for 97 saurischian taxa. The latter was used to assess the degree of homoplasy of qualitative dental characters, address longstanding questions on the taxonomic and biostratigraphic value of theropod teeth, and explore the major evolutionary trends in the theropod dentition.

In smaller phylogenetic datasets for Theropoda, dental characters exhibit higher levels of homoplasy than non-dental characters, yet they still provide useful grouping information and optimize as local synapomorphies of smaller clades. In broader phylogenetic datasets, the degree of homoplasy displayed by dental and non-dental characters is not significantly different. Dental features on crown ornamentations, enamel texture and tooth microstructure have significantly less homoplasy than other dental features and can be used to identify many theropod taxa to ‘family’ or ‘sub-family’ level, and some taxa to genus or species. These features should, therefore, be a priority for investigations seeking to classify isolated teeth.

Our observations improve the taxonomic utility of theropod teeth and in some cases can help make isolated teeth useful as biostratigraphic markers. This proposed list of dental features in theropods should, therefore, facilitate future studies on the systematic paleontology of isolated teeth.