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2022
Guillaume, A. R. D., Natário C., Mateus O., & Moreno-Azanza M. (2022).  Plasticity in the morphology of the fused frontals of Albanerpetontidae (Lissamphibia; Allocaudata). Historical Biology. 1 - 18., 2022: Taylor & Francis Abstractplasticity_in_the_morphology_of_the_fused_frontals_of_albanerpetontidae_lissamphibia_allocaudata.pdfWebsite

ABSTRACTAlbanerpetontidae form an enigmatic extinct group of lissamphibians, ranging from the early Bathonian to the early Pleistocene. The Upper Jurassic outcrops of Portugal yield a large collection of material, suitable for addressing the intraspecific variation in and diagnostic potential of the characteristic fused frontals. We revise 58 specimens from the Guimarota beds of the Kimmeridgian Alcobaça Formation and describe 62 new frontal bones from the Kimmeridgian ? Tithonian Lourinh? Formation. Smaller specimens exhibit a vermicular dorsal ornamentation, while it is polygonal in larger specimens and other albanerpetontids. Compared to small specimens, larger specimens display: (1) larger ventrolateral crests extending posteriorly after the parietal margin; (2) a relatively shorter internasal process; (3) a frontal width across posterior edges relatively smaller; and (4) a ventromedian crest less pronounced. Morphometric analyses suggest a single species with different ontogenetic stages. Specimens are attributed to aff. Celtedens sp., based on a bell-shaped outline with a curved orbital margin (although variable in Portuguese specimens), and a flabellate, bulbous-shaped internasal process. The species is more similar to C. megacephalus than C. ibericus, but its phylogenetic position comprises an unresolved trichotomy. Our results show that intraspecific variation and homoplasy render the fused frontal non-diagnostic below the generic level.

Mateus, O., & Estraviz-López D. (2022).  A new theropod dinosaur from the early cretaceous (Barremian) of Cabo Espichel, Portugal: Implications for spinosaurid evolution. PLOS ONE. 17, 1-48., 02, Number 2: Public Library of Science Abstractjournal.pone_.0262614.pdfWebsite

Spinosaurids are some of the most enigmatic Mesozoic theropod dinosaurs due to their unique adaptations to aquatic environments and their relative scarcity. Their taxonomy has proven to be especially problematic. Recent discoveries from Western Europe in general, specifically Iberia, provide some of the best specimens for the understanding of their phylogeny, leading to the description of the spinosaurid Vallibonavenatrix cani and the recognition of the Iberian dinosaur Camarillasaurus cirugedae as one of them. Portuguese associated spinosaurid remains (ML1190) from the Papo Seco Formation (early Barremian) were previously assigned to Baryonyx walkeri but new material recovered in 2020 along with new phylogenetic analyses suggests a different phylogenetic placement, making their revision necessary. Here we show that these remains are not attributable to Baryonyx walkeri, but to a new genus and species, Iberospinus natarioi, gen. et sp. nov. The new taxon is characterized by the presence of a single Meckelian foramen in the Meckelian sulcus, a straight profile of the ventral surface of the dentary and a distal thickening of the acromion process of the pubis between other characters. Iberospinus natarioi is recovered as a sister taxon of the clade formed by Baryonyx and Suchomimus, and outside Spinosaurinae when Vallibonaventrix cani is excluded from the analysis. The description of this taxon reinforces Iberia as a hotspot for spinosaur biodiversity, with several endemic taxa for the region. As expected for the clade, the dentary displays a highly vascularized neurovascular network. The morphometric analysis of parts of the skeleton (pedal phalanx and caudal vertebrae, among others) shows an intermediate condition between basal tetanurans and spinosaurines.

Rotatori, F. M., Moreno-Azanza M., & Mateus O. (2022).  Reappraisal and new material of the holotype of Draconyx loureiroi (Ornithischia: Iguanodontia) provide insights on the tempo and modo of evolution of thumb-spiked dinosaurs. Zoological Journal of the Linnean Society. , 02 Abstractrotatori_etal2022.pdfWebsite

{The Upper Jurassic Lourinhã Formation is well known for its rich assemblage of fossil vertebrates. In this formation, ornithopod dinosaurs are represented by two iguanodontian species, Eousdryosaurus nanohallucis and Draconyx loureiroi. We recently became aware of unreported material belonging to the holotype of Draconyx loureiroi, consisting of partially articulated manual elements. We here re-describe the holotype specimen ML 357, including the newly discovered material. The specimen was subjected to CT-scanning and its surface data used to assess anatomical characters. Linear measurements of metatarsal III were used to estimate the body length of the specimen. The Draconyx loureiroi holotype was included in two datasets and analysed with maximum parsimony and Bayesian inference approaches to estimate evolutionary rates among Iguanodontia. We present evidence that Draconyx loureiroi is a valid taxon nested in Styracosterna and is clearly diagnosable by a unique combination of characters. Both maximum parsimony and Bayesian inference indicate high evolutionary rates across the Jurassic/Cretaceous transition for the base of Iguanodontia. Length estimation suggests that Draconyx loureiroi was a relatively small, bipedal and possibly cursorial animal. Given its basal phyletic position, we interpret this bauplan was the ancestral condition for Styracosterna, that only later in the Cretaceous evolved into giant quadrupedal forms.}

Estraviz López, D., & Mateus O. (2022).  Bearing the weight: Technical recovery of brown bear fossils (Ursus arctos) from Algar do Vale da Pena, Portugal. XX EJIP. , Cañaveral de León Abstractestraviz-lpezmateus2022bearingtheweighttechnicalrecoveryofbrownbearfossilsursusarctosfromalgardovaledapenaportugal.pdf

The Algar do Vale da Pena is a cave that was discovered during limestone mining works around 1980, at the Natural Park of Serras de Aire e Candeeiros, Portugal. The entrance to the cave, through the collapsed roof, is a 30 meter near-vertical well, inaccessible without means of vertical progression and specialized equipment. Soon after the discovery of the cave, bone material belonging to bears and hundreds of bear claw marks were located inside it. Nevertheless, the technical descent and the extraordinary difficulties of retrieving the calcite flowstones that encased the bones prevented scientists from undertaking excavations for nearly 40 years. Since 2016 a series of expeditions by a team of paleontologists from NOVA University and Museum of Lourinhã recovered more than 20 disarticulated remains from five bone accumulations, separated more than five meters apart, which given the level of erosion and breakage, are para-autochthonous in origin. These are interpreted as belonging to different individuals. Morphological characters, like a relatively elongated third phalanx, the clear separation of paracone-metacone of the first upper molar and the ventral position of the mandibular condyle; as well as numerous morphometric characters, allow to ascribe the remains to Ursus arctos. Nevertheless, the main finding from the cave is a complete skull with an articulated mandible; which denotes absence of transport, encased within a 180 kg calcite flowstone, including other skeletal remains as well, which could not be extracted from the cave until 2021. This block was removed with the help of members of several speleological groups. It promises a wealth of information about fossil brown bears, being the most complete bear fossil ever recovered in Portugal. It is currently being dated trough magnetostratigraphy and prepared. We consider this intervention as an extraordinary example of citizen science applied to paleontology

Reboleira, A., & Mateus O. (2022).  Geologia, Grutas e Fauna Subterrânea do Planalto das Cesaredas, Portugal. Captar. 11, 1-19.: DOI: https://doi.org/10.34624/captar.v11i0.27451 Abstractreboleira_e_mateus_2022.pdf

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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.

Guillaume, A. R. D., Costa F., & Mateus O. (2022).  Stegosaur tracks from the Upper Jurassic of Portugal: new occurrences and perspectives. Ciências da Terra / Earth Sciences Journal. 20(1), 37-60. Abstractguillaumeetal.pdf

The record of Late Jurassic stegosaur tracks from the Lourinhã Formation (Kimmeridgian-Tithonian) is here revised. Thirty-eight dinosaur tracks, preserved as natural infill casts, are here reported, and thirty-two of them are attributed to the ichnogenus Deltapodus. Four of those present impressions of skin, with polygonal scales and random pattern. Deltapodus is the most common ichnogenus in the track record of the Lourinhã Formation. The sizes and shape suggest one single dacentrurine trackmaker, which could be Miragaia longicollum, also common in the same horizons.

2021
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
Beccari, V., Pinheiro F. L., Nunes I., Anelli L. E., Mateus O., & Costa F. R. (2021).  Osteology of an exceptionally well-preserved tapejarid skeleton from Brazil: Revealing the anatomy of a curious pterodactyloid clade. PLOS ONE. 16(8), e0254789 - ., 2021/08/25: Public Library of Science Abstractbeccari_et_al_2021.pdfWebsite

A remarkably well-preserved, almost complete and articulated new specimen (GP/2E 9266) of Tupandactylus navigans is here described for the Early Cretaceous Crato Formation of Brazil. The new specimen comprises an almost complete skeleton, preserving both the skull and post-cranium, associated with remarkable preservation of soft tissues, which makes it the most complete tapejarid known thus far. CT-Scanning was performed to allow the assessment of bones still covered by sediment. The specimen can be assigned to Tupa. navigans due to its vertical supra-premaxillary bony process and short and rounded parietal crest. It also bears the largest dentary crest among tapejarine pterosaurs and a notarium, which is absent in other representatives of the clade. The new specimen is here regarded as an adult individual. This is the first time that postcranial remains of Tupa. navigans are described, being also an unprecedented record of an articulated tapejarid skeleton from the Araripe Basin.

Marx, M. P., Mateus O., Polcyn M. J., Schulp A. S., Gonçalves O. A., & Jacobs L. L. (2021).  The cranial anatomy and relationships of Cardiocorax mukulu (Plesiosauria: Elasmosauridae) from Bentiaba, Angola. PLOS ONE. 16(8), e0255773 - ., 2021/08/17: Public Library of Science Abstractmarx_et_al_2021_cardiocorax_angola.pdfWebsite

We report a new specimen of the plesiosaur Cardiocorax mukulu that includes the most complete plesiosaur skull from sub-Saharan Africa. The well-preserved three-dimensional nature of the skull offers rare insight into the cranial anatomy of elasmosaurid plesiosaurians. The new specimen of Cardiocorax mukulu was recovered from Bentiaba, Namibe Province in Angola, approximately three meters above the holotype. The new specimen also includes an atlas-axis complex, seventeen postaxial cervical vertebrae, partial ribs, a femur, and limb elements. It is identified as Cardiocorax mukulu based on an apomorphy shared with the holotype where the cervical neural spine is approximately as long anteroposteriorly as the centrum and exhibits a sinusoidal anterior margin. The new specimen is nearly identical to the holotype and previously referred material in all other aspects. Cardiocorax mukulu is returned in an early-branching or intermediate position in Elasmosauridae in four out of the six of our phylogenetic analyses. Cardiocorax mukulu lacks the elongated cervical vertebrae that is characteristic of the extremely long-necked elasmosaurines, and the broad skull with and a high number of maxillary teeth (28–40) which is characteristic of Aristonectinae. Currently, the most parsimonious explanation concerning elasmosaurid evolutionary relationships, is that Cardiocorax mukulu represents an older lineage of elasmosaurids in the Maastrichtian.

Fernandes, A. E., Mateus O., Bauluz B., Coimbra R., Ezquerro L., Núñez-Lahuerta C., Suteu C., & Moreno-Azanza M. (2021).  The Paimogo Dinosaur Egg Clutch Revisited: Using One of Portugal’s Most Notable Fossils to Exhibit the Scientific Method. Geoheritage. 13(3), 66., 2021 Abstractfernandes_et_al-2021-geoheritage.pdfWebsite

Found in the Upper Jurassic outcrops of Lourinhã, Portugal, and first published in 1997, the Paimogo dinosaur egg clutch is one of Portugal’s most remarkable fossils, with over one hundred eggs preserved in association with embryonic bones, of the allosauroid theropod Lourinhanosaurus. However, many questions about it have remained unanswered, even until the present day. After its discovery, this extraordinary fossil became the keystone of a small local museum, greatly kick-starting regional tourism, while also holding the fossils in trust for future generations to study. More than 20 years later, continually sustained paleontological interest from the public has even given rise to both a highly successful dinosaur theme park in the region and an aspiring UNESCO Geopark. Recently, a multidisciplinary team of preparators, paleontologists, sedimentologists, mineralogists, and geochemists revisited an unopened jacket from the original excavation using an array of techniques to address various questions. Studies are ongoing, but the corpus of information obtained and the methodologies utilized to gather data have offered an opportunity to design an exhibit around the history of the Paimogo clutch, highlighting the scientific methods involved, and asserting the importance of preserving geological heritage for the future, when new tools will doubtlessly become available to provide yet another new look at old fossils. Here, we describe our analytical procedures and present an innovative exhibit designed to introduce to the public the latest advances on the research behind an iconic piece of Portuguese geoheritage, increasing its value both as a research item and as an educational resource.

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
Marques, M. I. F., & Mateus O. (2021).  Dinosaur tracksites from Portugal, focused on the carbonated platform of North and Central Lusitanian Basin. 3rd Palaeontological Virtual Congress. 210.: ISBN 978-84-09-36657-6 Abstractmarques_mateus_2021_pvc3_tracks.pdf

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Ezquerro, L., Balauz B., Coimbra R., Nuñez-Lahuerta C., Mateus O., Román T., & Moreno-Azanza M. (2021).  Evidence of sedimentary remodel of Jurassic theropod egg clutches (Lourinhã, Portugal). 18th Conference of the EAVP-Abstract book. 72-73. Abstractezquerro_et_al_2021_sedimentary_remodel.pdf

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Moreno-Azanza, M., Mateus O., Bauluz B., Coimbra R., Ezquerro L., & Núñez-Lahuerta C. (2021).  Hatching in Portugal: a new look to old eggs. XIX Encontro de Jovens Investigadores em Paleontologia. 22. Abstractmoreno-azanza_et_al_2021_eggs_ejip.pdf

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Beccari, V., Mateus O., Wings O., Milàn J., & Clemmensen L. B. (2021).  Issi saaneq gen. et sp. nov.—A New Sauropodomorph Dinosaur from the Late Triassic (Norian) of Jameson Land, Central East Greenland. Diversity. 13, , Number 11 Abstractdiversity-13-00561-v2.pdfWebsite

The Late Triassic (Norian) outcrops of the Malmros Klint Formation, Jameson Land (Greenland) have yielded numerous specimens of non-sauropod sauropodomorphs. Relevant fossils were briefly reported in 1994 and were assigned to Plateosaurus trossingensis. However, continuous new findings of early non-sauropod sauropodomorphs around the globe facilitate comparisons and allow us to now revise this material. Here, the non-sauropod sauropodomorph Issi saaneq gen. et sp. nov. is described based on two almost complete and articulated skulls. The two skulls represent a middle-stage juvenile and a late-stage juvenile or subadult. Issi saaneq differs from all other sauropodomorphs by several unique traits: (1) a small foramen at the medial surface of the premaxilla; (2) an anteroposteriorly elongated dorsoposterior process of the squamosal; (3) a relatively high quadrate relative to rostrum height; (4) a well-developed posterodorsal process of the articular. These features cannot be explained by taphonomy, ontogeny, or intraspecific variation. Issi saaneq shows affinities to Brazilian plateosaurids and the European Plateosaurus, being recovered as the sister clade of the latter in our phylogenetic analysis. It is the northernmost record of a Late Triassic sauropodomorph, and a new dinosaur species erected for Greenland. Issi saaneq broadens our knowledge about the evolution of plateosaurid sauropodomorphs.

Guillaume, A. R. D., Natário C., Moreno-Azanza M., & Mateus O. (2021).  New material ascribed to Albanerpetontidae (Lissamphibia; Allocaudata) from the Lourinhã Formation: evidence for intraspecific variation. XIX Encontro de Jovens Investigadores em Paleontologia. 50-51. Abstractguillaume_et_al_2021_albanerpetontidae.pdf

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Guillaume, A. R. D., Natário C., Moreno-Azanza M., & Mateus O. (2021).  New occurences of Celtedens (Lissamphibia: Albanerpetontidae) from the Lourinhã Formation. XVIII Conference of the European Association of Vertebrate Palaeontologists. 87. Abstractguillaume_et_al_2021_celtedens.pdf

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López-Rojas, V., Mateus O., Milàn J., Wings O., Klein N., & Clemmensen L. B. (2021).  A new phytosaur from the Late Triassic of Jameson Land, Greenland. 3rd Palaeontological Virtual Congress. 207.: ISBN 978-84-09-36657-6 Abstractlopez_rojas_2021_pvc3_greenland.pdf

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Puértolas-Pascual, E., Marx M., Mateus O., Saleiro A., Fernandes A. E., Marinheiro J., Tomás C., & Mateus S. (2021).  A new plesiosaur from the Lower Jurassic of Portugal and the early radiation of Plesiosauroidea. Acta Palaeontologica Polonica. 66(2), 369-388. Abstracta_new_plesiosaur_from_the_lower_jurassic_of_portugal_and_the_early_radiation_of_plesiosauroidea.pdfWebsite

A new plesiosaur partial skeleton, comprising most of the trunk and including axial, limb, and girdle bones, was collected in the lower Sinemurian (Coimbra Formation) of Praia da Concha, near São Pedro de Moel in central west Portugal. The specimen represents a new genus and species, Plesiopharos moelensis gen. et sp. nov. Phylogenetic analysis places this taxon at the base of Plesiosauroidea. Its position is based on this exclusive combination of characters: presence of a straight preaxial margin of the radius; transverse processes of mid-dorsal vertebrae horizontally oriented; ilium with sub-circular cross section of the shaft and subequal anteroposterior expansion of the dorsal blade; straight proximal end of the humerus; and ventral surface of the humerus with an anteroposteriorly long shallow groove between the epipodial facets. In addition, the new taxon has the following autapomorphies: iliac blade with less expanded, rounded and convex anterior flank; highly developed ischial facet of the ilium; apex of the neural spine of the first pectoral vertebra inclined posterodorsally with a small rounded tip. This taxon represents the most complete and the oldest plesiosaur species in the Iberian Peninsula. It is also the most complete, best preserved, and oldest marine vertebrate in the region and testifies to the incursion of marine reptiles in the newly formed proto-Atlantic sea, prior to the Atlantic Ocean floor spreading in the Early Cretaceous.

Clemmensen, L. B., Lindström S., Mateus O., Mau M., Milàn J., & Kent D. V. (2021).  A new vertebrate fossil-bearing layer in the Rhætelv Formation (Kap Stewart Group) of central East Greenland: evidence of a Hettangian marine incursion into the continental Jameson Land Basin. Lethaia. n/a, , Number n/a Abstractlet.12449.pdfWebsite

The Kap Stewart Group (Rhaetian-Sinemurian, Triassic–Early Jurassic) of the Jameson Land Basin in central East Greenland has traditionally been regarded as a strictly continental unit with delta and perennial lake sediments. New finds of plesiosaur bone remain in a thin storm deposited sandstone bed in the middle part of the Rhætelv Formation of the Kap Stewart Group, however, indicates a likely period of marine influence. At the study area at the eastern margin of the basin, the Rhætelv Formation is 300-m thick and overlies unconformably the Norian Fleming Fjord Group. The bone-bearing sandstone occurs 190 m above the base of the group and is closely associated with black laminated mudstones; palynological investigation of three samples from these mudstones indicates that they are of a younger Hettangian age. The Hettangian was a relatively short stage (201.3–199.5 Ma) and elsewhere characterized by two episodes of sea-level highstands. Assuming that the marine incursion in the Jameson land Basin evidenced by the plesiosaur fossil remains took place during the youngest of these sea-level highstands, the bone-bearing bed of the Rhætelv Formation can be dated to 200 Ma and thereby gives the first numerical age constraint of this hitherto poorly dated succession.

Mateus, O. (2021).  Overview of vertebrate fossils from Portugal, focus on Mesozoic dinosaurs. 3rd Palaeontological Virtual Congress. 15.: ISBN 978-84-09-36657-6 Abstractmateus_2021_pvc3_key_note_speaker.pdf

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Milàn, J., Mateus O., Mau M., Rudra A., Sanei H., & Clemmensen L. B. (2021).  A possible phytosaurian (Archosauria, Pseudosuchia) coprolite from the Late Triassic Fleming Fjord Group of Jameson Land, central East Greenland. Bulletin of the Geological Society of Denmark. 69, 71-80. Abstractmilan_et_al_2021_coprolites_greenland_bull69-71-80.pdfWebsite

A large, well-preserved vertebrate coprolite was found in a lacustrine sediment in the Malmros Klint Formation of the Late Triassic Fleming Fjord Group in the Jameson Land Basin, central East Greenland. The size and internal and external morphology of the coprolite is consistent with that of crocodilian coprolites and one end of the coprolite exhibits evidence of post-egestion trampling. As the associated vertebrate fauna of the Fleming Fjord Group contains abundant remains of pseudosuchian phytosaurs, the coprolite is interpreted as being from a large phytosaur.

Rotatori, F. M., Moreno-Azanza M., & Mateus O. (2021).  Re-evaluation of the Holotype of Draconyx loureiroi (Dinosauria, Ornithopoda) with report of new holotype material. PALEODAYS 2021 – XXI Convegno della Società Paleontologica Italiana. 73. Abstractrotatoriet_l_2021_paleodays.pdf

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Rotatori, F. M., Silva B. C., Moreno-Azanza M., & Mateus O. (2021).  A systematic overview of medium and large-sized iguanodontians (Dinosauria, Ornithopoda) from the Upper Jurassic Lourinhã Formation, Portugal. XIX Encontro de Jovens Investigadores em Paleontologia. 62-63. Abstractrotatoriet_l_2021_ejip.pdf

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Moreno-Azanza, M., Ezquerro L., Gasca J. M., Díaz-Berenguer E., Nuñez-Lahuerta C., Pérez-Pueyo M., Puértolas-Pascual E., Sellés A. G., Vila B., & Laita E. (2021).  Two latest Cretaceous egg localities in the external sierras (Southern Pyrenees, Huesca Province, NE Spain). Palaeovertebrata - XVIII annual conference of the European Association of Vertebrate Palaeontologists. 44, 120-121. Abstractmoreno-azanza_et_al_2021_eggs_eavp_abstract.pdf

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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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2020
Guillaume, A. R. D., Moreno-Azanza M., Puértolas-Pascual E., & Mateus O. (2020).  Palaeobiodiversity of crocodylomorphs from the Lourinhã Formation based on the tooth record: insights into the palaeoecology of the Late Jurassic of Portugal. Zoological Journal of the Linnean Society. 189(2), 549–583., 11 Abstractguillaume_et_al_palaeobiodiversity_of_crocodylomorphs_from_the.pdfWebsite

{Crocodylomorphs were a diverse clade in the Late Jurassic of Portugal, with six taxa reported to date. Here we describe 126 isolated teeth recovered by screen-washing of sediments from Valmitão (Lourinhã, Portugal, late Kimmeridgian–Tithonian), a vertebrate microfossil assemblage in which at least five distinct crocodylomorph taxa are represented. Ten morphotypes are described and attributed to five clades (Lusitanisuchus, Atoposauridae, Goniopholididae, Bernissartiidae and an undetermined mesoeucrocodylian). Four different ecomorphotypes are here proposed according to ecological niches and feeding behaviours: these correspond to a diet based on arthropods and small vertebrates (Lusitanisuchus and Atoposauridae), a generalist diet (Goniopholididae), a durophagous diet (Bernissartiidae) and a carnivorous diet. Lusitanisuchus mitracostatus material from Guimarota is here redescribed to achieve a better illustration and comparison with the new material.This assemblage shares similar ecomorphotypes with other Mesozoic west-central European localities, where a diversity of crocodylomorphs lived together, avoiding direct ecological competition through niche partitioning. The absence of large marine crocodylomorphs, present in other contemporaneous assemblages, is here interpreted as evidence that the Valmitão assemblage was deposited in a freshwater environment, although sample bias cannot be completely ruled out. These affinities are further supported by the presence of lanceolate and leaf-shaped teeth associated with continental clades.}

Park, J. - Y., Lee Y. - N., Currie P. J., Kobayashi Y., Koppelhus E., Barsbold R., Mateus O., Lee S., & Kim S. - H. (2020).  Additional skulls of Talarurus plicatospineus (Dinosauria: Ankylosauridae) and implications for paleobiogeography and paleoecology of armored dinosaurs. Cretaceous Research. 108, 104340. Abstractpark_et_al_2020_additional_skulls_of_talarurus_plicatospineus_dinosauria_final.pdfWebsite

Three new additional skull specimens of Talarurus plicatospineus have been recovered from the Upper Cretaceous (Cenomanian–Santonian) Bayanshiree Formation, of Bayan Shiree cliffs, eastern Gobi Desert, Mongolia. The skulls feature unique characters such as an anteriorly protruded single internarial caputegulum, around 20 flat or concave nasal-area caputegulae surrounded by a wide sulcus, a vertically oriented elongate loreal caputegulum with a pitted surface, an elongate lacrimal caputegulum positioned above the posterodorsal border of the maxilla, two longitudinally arranged large frontoparietal caputegulae surrounded by smaller rhomboid caputegulae, small but elongate medial supraorbital caputegulae, a posterior supraorbital caputegulum that is four times larger than the anterior one, up to three transverse parallel grooves on the dorsal surface of the posterior supraorbital caputegulum, postocular caputegulae along the ventral to posterior rim of the orbit that extend almost to the anteroventral margin of the squamosal horn, a longitudinal furrow tapering towards the apex of the squamosal horn, a lateral nuchal caputegulum four to five times larger than other nuchal caputegulae, and a pterygovomerine keel with a ventral margin that is dorsally positioned to the alveolar ridge. The phylogenetic analysis result showed that Talarurus is sister to the clade that includes the derived Asian ankylosaurines (Saichania chulsanensis, Tarchia kielanae, and Zaraapelta nomadis). It also shows that there was dispersal of ankylosaurines from Asia into western North America before the Cenomanian. Moreover, the rostral differences between Talarurus and Tsagantegia, another ankylosaur from the same formation, suggest possible niche partitioning between these taxa.

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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Clemmensen, L. B., Kent D. V., Mau M., Mateus O., & Milàn J. (2020).  Triassic lithostratigraphy of the Jameson Land basin (central East Greenland), with emphasis on the new Fleming Fjord Group. Bulletin of the Geological Society of Denmark. 68, 95–132. Abstractclemmensen_et_al_2020_triassic_lithostratigraphy_of_the_jameson_land_basin.pdfWebsite

The lithostratigraphy of the Triassic deposits of the Jameson Land Basin in central East Greenland is revised. The new Scoresby Land Supergroup is now composed of the Wordie Creek, Pingo Dal, Gipsdalen and Fleming Fjord Groups. This paper only deals with the lithostratigraphy of the late Early-Late Triassic continental deposits of the latter three groups with emphasis on the vertebratebearing Fleming Fjord Group. The new Pingo Dal Group consists of three new formations, the Rødstaken, Paradigmabjerg and Klitdal Formations (all elevated from members), the new Gipsdalen Group consists of three new formations, the Kolledalen, Solfaldsdal (with the new Gråklint Member) and Kap Seaforth Formations (all elevated from members), and the new Fleming Fjord Group is subdivided into three new formations, the Edderfugledal, Malmros Klint and Ørsted Dal Formations (all elevated from members). The Edderfugledal Formation contains two cyclic bedded, lacustrine members, a lowermost Sporfjeld Member (elevated from beds), and an uppermost Pingel Dal Member (elevated from beds). The lacustrine red beds of the Malmros Klint Formation are not subdivided. The lacustrine and fluvial Ørsted Dal Formation contains three new members. In the eastern and central part of the basin, the formation is initiated by cyclic bedded, red lacustrine mudstones of the Carlsberg Fjord Member (elevated from beds), while in the northwestern part of the basin the lowermost part of the formation is composed of grey fluvial conglomerates and sandstones with subordinate red mudstones of the Bjergkronerne Member (elevated from beds). The uppermost part of the formations in most of the basin is composed of cyclic bedded, variegated lacustrine mudstones and grey to yellowish marlstones of the Tait Bjerg Member (elevated from beds). The sediments in the Fleming Fjord Group contain remains of a rich and diverse vertebrate fauna including dinosaurs, amphibians, turtles, aeotosaurs, pterosaurs, phytosaurs and mammaliaforms. Most vertebrate bones have been found in uppermost Malmros Klint Formation, and in the Carlsberg Fjord and Tait Bjerg Members. The Norian–early Rhaetian, lacustrine Fleming Fjord Group was deposited at about 41° N on the northern part of the supercontinent Pangaea. Lacustrine sedimentation was controlled by seasonal as well as longer-term (orbital) variation in precipitation. Precipitation was probably brought to the basin by southwesterly winds. The lacustrine sediments of the uppermost Fleming Fjord Group show deposition during increasingly humid conditions changing the lake environment from an ephemeral lake-steppe area to a perennial lake. This evolution of lake environment suggests a change from a winter-wet temperate climate to one with precipitation throughout the year.

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
2019
Puértolas-Pascual, E., & Mateus O. (2019).  A three-dimensional skeleton of Goniopholididae from the Late Jurassic of Portugal: implications for the Crocodylomorpha bracing system. Zoological Journal of the Linnean Society. , 10 Abstractpuertolas-pascual__mateus_2019_croc.pdfWebsite

{We here describe an articulated partial skeleton of a small neosuchian crocodylomorph from the Lourinhã Formation (Late Jurassic, Portugal). The skeleton corresponds to the posterior region of the trunk and consists of dorsal, ventral and limb osteoderms, dorsal vertebrae, thoracic ribs and part of the left hindlimb. The paravertebral armour is composed of two rows of paired osteoderms with the lateral margins ventrally deflected and an anterior process for a ‘peg and groove’ articulation. We also compare its dermal armour with that of several Jurassic and Cretaceous neosuchian crocodylomorphs, establishing a detailed description of this type of osteoderms.These features are present in crocodylomorphs with a closed paravertebral armour bracing system. The exceptional 3D conservation of the specimen, and the performance of a micro-CT scan, allowed us to interpret the bracing system of this organism to assess if previous models were accurate. The characters observed in this specimen are congruent with Goniopholididae, a clade of large neosuchians abundant in most semi-aquatic ecosystems from the Jurassic and Early Cretaceous of Laurasia. However, its small size, contrasted with the sizes observed in goniopholidids, left indeterminate whether it could have been a dwarf or juvenile individual. Future histological analyses could shed light on this.}

Schulp, A. S., Mateus O., Polcyn M., Gonçalves A., & Jacobs L. L. (2019).  Angola and its role in the paleobiogeography of Gondwana. Journal of Vertebrate Paleontology, Program and Abstracts. 188.schulp_et_al_2019_angola_svp_abstract.pdf
Azanza, M. M., Coimbra R., Puértolas-Pascual E., Russo J., Bauluz B., & Mateus O. (2019).  Crystallography of Lourinhanosaurus eggshells (Dinosauria, Theropoda, Allosauroidea). Journal of Vertebrate Paleontology, Program and Abstracts. 156-157.moreno_azanza_et_al_2019_svp_abstract.pdf
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.

Mateus, O., Callapez P. M., Polcyn M. J., Schulp A. S., Gonçalves A. O., & Jacobs L. L. (2019).  The Fossil Record of Biodiversity in Angola Through Time: A Paleontological Perspective. (Huntley, Brian J., Russo, Vladimir, Lages, Fernanda, Ferrand, Nuno, Ed.).Biodiversity of Angola: Science & Conservation: A Modern Synthesis. 53–76.: Springer International Publishing Abstractmateus2019_chapter_thefossilrecordofbiodiversityi.pdf

This chapter provides an overview of the alpha paleobiodiversity of Angola based on the available fossil record that is limited to the sedimentary rocks, ranging in age from Precambrian to the present. The geological period with the highest paleobiodiversity in the Angolan fossil record is the Cretaceous, with more than 80{%} of the total known fossil taxa, especially marine molluscs, including ammonites as a majority among them. The vertebrates represent about 15{%} of the known fauna and about one tenth of them are species firstly described based on specimens from Angola.

Belvedere, M., Castanera D., Meyer C. A., Marty D., Mateus O., Silva B. C., Santos V. F., & Cobos A. (2019).  Late Jurassic globetrotters compared: A closer look at large and giant theropod tracks of North Africa and Europe. Journal of African Earth Sciences. 158, 103547. Abstractbelvedere_et_al_2019_jurassic_globetrotters_compared.pdfWebsite

Late Jurassic theropod tracks are very common both in North Africa and Europe. Two recently described ichnotaxa Megalosauripus transjuranicus and Jurabrontes curtedulensis from the Kimmeridgian of Switzerland show the coexistence of two apex predators in the same palaeoenvironment. Similar tracks can be found in tracksites from the Iberian Peninsula and from Morocco. Here, we further explore the similarities among the Swiss ichnotaxa and the other tracks from Germany (Kimmeridgian), Spain (Tithonian-Berriasian), Portugal (Oxfordian-Tithonian) and Morocco (Kimmeridgian) through novel three-dimensional data comparisons. Specimens were grouped in two morphotypes: 1) large and gracile (30 < Foot Length<50 cm) and 2) giant and robust (FL > 50 cm). The analyses show a great morphological overlap among these two morphotypes and the Swiss ichnotaxa (Megalosauripus transjuranicus and Jurabrontes curtedulensis, respectively), even despite the differences in sedimentary environment and age. This suggests a widespread occurrence of similar ichnotaxa along the western margin of Tethys during the Late Jurassic. The new data support the hypothesis of a Gondwana-Laurasia faunal exchange during the Middle or early Late Jurassic, and the presence of migratory routes around the Tethys.

Russo, J., & Mateus O. (2019).  A new Ankylosaur Dinosaur Skeleton from the Upper Jurassic of Portugal. Journal of Vertebrate Paleontology, Program and Abstracts. 184.russo__mateus_2019_svp_abstract.pdf
Guillaume, A. R., Moreno-Azanza M., & Mateus O. (2019).  New lissamphibian material from the Lourinhã Formation (Late Jurassic, Portugal). Journal of Vertebrate Paleontology, Program and Abstracts. 112.guillaume_et_al_2019_svp_abstract.pdf
Rotatori, F., Moreno-Azanza M., & Mateus O. (2019).  New ornithopod dinosaur remains from the Late Jurassic Lourinhã Formation. 17th Conference of the EAVP. 100., Bruxelles: European Association of Vertebrate Paleontologistsrotatori_et_al_2019_ornithopod_portugal_eavp_2019_abstract.pdf
Mateus, O., Callapez P. M., Polcyn M. J., Schulp A. S., Gonçalves A. O., & Jacobs L. L. (2019).  O registo fóssil da biodiversidade em Angola ao longo do tempo: uma perspectiva paleontológica. (Huntley B.J., Russo V., Lages F., Ferrand N., Ed.).Biodiversidade de Angola: Ciência e Conservação - Uma Síntese Moderna. 89-116., Porto: Arte & Ciência Abstractmateus_et_al_2019_paleobiodiversidade_angola.pdf

Este capítulo apresenta uma visão geral da paleobiodiversidade alfa de Angola com base no registo fóssil disponível, o qual se limita às rochas sedimentares, a sua idade variando entre o Pré‑Câmbrico e o pre‑
sente. O período geológico com a maior paleobiodiversidade no registo fóssil angolano é o Cretácico, com mais de 80% do total dos táxones fósseis conhecidos, especialmente moluscos marinhos, sendo estes na sua maioria
amonites. Os vertebrados representam cerca de 15% da fauna conhecida e cerca de um décimo destes são espécies descritas pela primeira vez com base em espécimes de Angola.

Park, J., Lee Y., Currie P. J., Kobayashi Y., Koppelhus E. B., Barsbold R., Lee S., Kim S., & Mateus O. (2019).  Three new skulls of the Late Cretaceous armored dinosaur Talarurus plicatospineus Maleev, 1952. Journal of Vertebrate Paleontology, Program and Abstracts. 165-166.park_et_al_2019_svp_abstract.pdf