Triassic to Lower Jurassic deposits known as the Silves Group in the Algarve, southern Portugal, have been studied for over 150 years. However, many of this unit’s sedimentological, stratigraphical, and palaeontological aspects remain poorly documented. Here, we present novel observations on sedimentology, stratigraphy, taphonomy, and fauna at the Rocha da Pena site, located in the central part of the Algarve Basin. The investigated sequence is established to correspond to the upper part of the Silves Group. The mudstone, calcrete, and palustrine carbonate facies comprise most of the sequence thickness and are interpreted as having been deposited within coastal alluvial mudflats to palustrine settings under semi-arid and seasonal climates. The overlying siltstone and sandstone facies indicate an environmental shift towards tidally influenced environments, subsequently covered by the latest Triassic to earliest Jurassic volcaniclastics and basaltic lava flows. Furthermore, novel faunal elements, including actinopterygian and unionoid bivalves, are described from mudstone layers. New fossiliferous beds are identified within palustrine facies that yield numerous but poorly preserved materials assigned to cyamodontoid placodonts, hybodont sharks, and actinopterygians. The poor preservation of the remains is attributed to the pedogenetic processes prevalent in the palustrine depositional setting. A distinct faunal composition between the mudstone and palustrine facies is observed. It is preliminarily hypothesized to be likely linked with salinity fluctuations, but sampling bias cannot currently be excluded. The recovered vertebrate fauna aligns most closely with the Carnian and, to a lesser extent, the Norian fossil record. Nonetheless, the precise age of the fossil-bearing levels remains uncertain and can currently be reliably constrained to the upper Carnian–Rhaetian interval. Consequently, this work provides new insights into the palaeoenvironmental evolution of the western Tethys margin during the Late Triassic and highlights the relevance of the Silves Group in reconstructing coastal-continental ecosystem dynamics in southwestern Iberia.Triassic to Lower Jurassic deposits known as the Silves Group in the Algarve, southern Portugal, have been studied for over 150 years. However, many of this unit’s sedimentological, stratigraphical, and palaeontological aspects remain poorly documented. Here, we present novel observations on sedimentology, stratigraphy, taphonomy, and fauna at the Rocha da Pena site, located in the central part of the Algarve Basin. The investigated sequence is established to correspond to the upper part of the Silves Group. The mudstone, calcrete, and palustrine carbonate facies comprise most of the sequence thickness and are interpreted as having been deposited within coastal alluvial mudflats to palustrine settings under semi-arid and seasonal climates. The overlying siltstone and sandstone facies indicate an environmental shift towards tidally influenced environments, subsequently covered by the latest Triassic to earliest Jurassic volcaniclastics and basaltic lava flows. Furthermore, novel faunal elements, including actinopterygian and unionoid bivalves, are described from mudstone layers. New fossiliferous beds are identified within palustrine facies that yield numerous but poorly preserved materials assigned to cyamodontoid placodonts, hybodont sharks, and actinopterygians. The poor preservation of the remains is attributed to the pedogenetic processes prevalent in the palustrine depositional setting. A distinct faunal composition between the mudstone and palustrine facies is observed. It is preliminarily hypothesized to be likely linked with salinity fluctuations, but sampling bias cannot currently be excluded. The recovered vertebrate fauna aligns most closely with the Carnian and, to a lesser extent, the Norian fossil record. Nonetheless, the precise age of the fossil-bearing levels remains uncertain and can currently be reliably constrained to the upper Carnian–Rhaetian interval. Consequently, this work provides new insights into the palaeoenvironmental evolution of the western Tethys margin during the Late Triassic and highlights the relevance of the Silves Group in reconstructing coastal-continental ecosystem dynamics in southwestern Iberia.

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Dyrosauridae are one of the few clades of large marine vertebrates that survived the Cretaceous/Palaeogene (K–Pg) extinction event. The early diversification of this clade, dated to the Cretaceous, is still poorly understood. We describe a new specimen of Dyrosauridae from the Late Cretaceous of Bentiaba, Angola, represented by a posterior portion of the skull, a left ectopterygoid fragment, and a tooth. Comparative morphological analysis reveals a unique combination of characters distinguishing it from known dyrosaurid taxa but due to the fragmentary nature of the specimen and the absence of key diagnostic features, we assign it to Hyposaurinae indet.. Phylogenetic relationships were tested through maximum parsimony and Bayesian inference, using the SFBD model with time-binning criteria for the K–Pg boundary. Both of our phylogenetic analyses recover this new specimen as Hyposaurinae, which is consistent with our comparative study. Evolutionary rates accelerated during the latest stages of the Cretaceous, although the fossil bias prevents the ability to appreciate their impact on cladogenetic events. We estimated diversification, fossilization, and extinction rates, and we did not find evidence of radiation after the K–Pg in this clade. Biogeographically, this discovery supports hypotheses of longirostrine crocodyliform dispersal in Africa leading to hyposaurine diversification during the Maastrichtian.

The Upper Jurassic beds of the Lusitanian Basin in central Portugal yield diverse dinosaurian fauna, dated to the Kimmeridgian–Tithonian interval. Saurischian dinosaurs are, overall, more abundant than their ornithischian counterparts, in terms of both specimens collected and species recognized. Iguanodontians are so far represented by the styracosternan Draconyx loureiroi, the dryosaurid Eousdryosaurus nanohallucis and the enigmatic dryomorphan Hesperonyx martinhotomasorum. Here we aim to highlight the diversity of this clade in the Late Jurassic of Portugal, presenting evidence for yet another species of ankylopollexian iguanodontian dinosaur, represented by the specimen SHN.JJS.015, which is housed at the Sociedade de História Natural, Torres Vedras. Detailed comparisons rule out attribution to previously known taxa, and phylogenetic analyses that include SHN.JJS.015 indicate early-diverging ankylopollexian affinities for this specimen. As there is no robust diagnosis, we do not erect a new formal species for it at this stage. Nevertheless, this specimen represents a previously unreported taxon that highlights greater diversity than previously estimated among the iguanodontians of the Late Jurassic and highlights the importance of Europe in diversification and dispersal events of this clade. A series of smaller, isolated femora from the same sub-basin as SHN.JJS.015 may represent the same taxon, presenting evidence of thriving communities of ankylopollexians during the Kimmeridgian–Tithonian interval in Portugal.

How snow leopard gradually adapted to the extreme environments in Tibet remains unexplored due to the scanty fossil record in Tibet. Here, we recognize five valid outside-Tibet records of the snow leopard lineage. Our results suggest that the snow leopard dispersed out of the Tibetan Plateau multiple times during the Quaternary. The osteological anatomy of the modern snow leopard shows adaptation to the steep slope and, to a lesser extent, cold/high-altitude environment. Fossils and phylogeny suggest that the snow leopard experienced a gradual strengthening of such adaptation, especially since the Middle Pleistocene ( 0.8 million years). Species distribution modeling suggests that the locations of the fossil sites are not within most suitable area, and we argue that local landscape features are more influential factors than temperature and altitude alone. Our study underscores the importance of integrating morphology, fossil records, and species distribution modeling, to comprehensively understand the evolution, ecology, and inform conservation strategies for endangered species. Integrated morphology, fossil records, and SDM reveal the evolution and adaptation in the snow leopard lineage.

The Late Triassic deposits in the Jameson Land Basin, central East Greenland, stand as a crucial fossil area, yielding a diverse Norian vertebrate fauna. This basin, situated at a palaeolatitude of 41° N on the northern rim of Pangea and bordered in the North by the Boreal Sea, was a hub of activity during the Late Triassic. A large ephemeral to perennial lake system developed in the central and eastern parts of the basin, with rivers transporting sediment from the uplands northwest of the basin. Our research focused on the microvertebrate remains recovered from an expedition to Jameson Land in 1991 which yielded significant findings. These specimens, meticulously photographed and listed in a catalogue, comprise 950 vertebrate remains. Notably, we have identified new taxa never described from the Late Triassic sediments of Greenland, including sharks (Lissodus, Rhomphaiodon), bony fish (Gyrolepis), and reptiles (Doswelliidae and Rhynchocephalia). The revision of two sphenodontians jaw fragments as Clevosauridae, in association with Lissodus lepagei, Lissodus cf. Lissodus minimus, Rhomphaiodon sp., Saurichthys sp., and Gyrolepis sp., which are taxa that are highly documented in Europe and Asia, confirms a relationship between faunas of Greenland and Eurasia during the Late Triassic, a statement previously based on macro vertebrate studies.

ABSTRACT The first mammaliaforms emerged in the Late Triassic, but their exact origins remain unclear due to the scarcity of fossils from this period. One of the earliest diverging mammaliaform groups, the order Docodonta, became unusually ecomorphologically diverse compared with other early mammals, and this may be connected to the possession of complex molar cusp morphology. The specimen described here, found in the Rhætelv Formation of the Kap Stewart Group (Rhaetian–Sinemurian) of central East Greenland, provides novel information on docodontan origins and evolution, as well as key biogeographic insights into early mammal dispersal. Nujalikodon cassiopeiae gen. et sp. nov. is the first mammaliaform found in the Rhætelv Formation, and is likely to be Early Jurassic (Hettangian) in age. Comprising an incomplete dentary with a single preserved molar, it was visualized using micro-computed tomography; the molar bears similarities to the putative early docodontan Delsatia, and docodontan Dobunnodon. Phylogenetic analysis places Nujalikodon cassiopeiae as a basal member of Docodonta or a close sister taxon, making it one of the oldest definitive docodontans and pushing the origin of the group back to at least the Early Jurassic. It provides insights into the development of docodontan dental complexity, a key factor in their ecological diversification during the Middle to Late Jurassic. Its presence in Greenland supports the hypothesis that docodontans originated in the region now comprising Europe and Greenland before dispersing across the rest of Laurasia.

The fundamental value of universal nomenclatural systems in biology is that they enable unambiguous scientific communication. However, the stability of these systems is threatened by recent discussions asking for a fairer nomenclature, raising the possibility of bulk revision processes for “inappropriate” names. It is evident that such proposals come from very deep feelings, but we show how they can irreparably damage the foundation of biological communication and, in turn, the sciences that depend on it. There are four essential consequences of objective codes of nomenclature: universality, stability, neutrality, and transculturality. These codes provide fair and impartial guides to the principles governing biological nomenclature and allow unambiguous universal communication in biology. Accordingly, no subjective proposals should be allowed to undermine them.

Allosaurus is one of the most famous theropod dinosaurs, but the validity and relationships between the different species have been confusing and often questioned. Portugal is relevant to the understanding of the genus in light of the discovery of A. europaeus ML415 from the Early Tithonian of Lourinhã and Allosaurus MNHNUL/AND.001 from Andrés. However, the exact classification and validity of these two specimens has always been controversial. The presence of Allosaurus in Portugal is strong evidence for a North America–Europe Late Jurassic dispersal, later supported by other taxa. A detailed cranial description and specimen-based phylogeny were performed and resolved many of the open questions: (1) The diversity of Allosaurus is limited to three named species: A. fragilis, A. europaeus, and A. jimmadseni. (2) Nine autapomorphies were found in A. europaeus, confirming the validity of the species. (3) Phylogenetic analyses place both Portuguese specimens in the genus Allosaurus, based on the following synapomorphies: jugal bone lateral view, relative heights of quadratojugal prongs, the dorsal prong is equal in height, the jugal bone in lateral view shows shallow accessory pneumatization of the antorbital fossa, the palatine pneumatic recess shape is small, and lacrimal horn morphology has a triangular horn. (4) The Andrés specimen is placed with the A. europaeus and they are considered here to be the same species, which is paleo-geographically and biochronologically congruent. (5) A. europaeus and A. jimmadseni are sister taxa and closer to each other than to A. fragilis. The genus is distributed in occurrences from the United States, Germany, and Portugal, and from the Late Kimmeridgian to the Late Tithonian, while the Cenomanian report from Japan is reidentified as Segnosaurus.

ABSTRACTVirtual palaeontology is a growing field, leading palaeontologists to better understand the microanatomy of many extinct species. The application of techniques such as CT and μCT-scanning allows the researchers to study micro-anatomical features in a non-invasive way and make inferences on the palaeobiology of animals. Dinosaurs have been extensively studied using these techniques, with particular focus on the microanatomy of the cranium, whereas relatively little is known of other cranial elements, such as the lower jaw. Here, we aim to fill this gap, describing the microanatomy of the specimen ML 768, an isolated dentary belonging to a dryosaurid iguanodontian dinosaur from the Upper Jurassic of Lourinhã Fm. The dentary ML 768 was subjected to μCT-scanning, and subsequently the data were segmented in Avizo and rendered in Blender. We identified functional and replacement teeth, recognising remnants of old replacement cycles. Furthermore, we mapped a rich neurovascular network present in the dentary and compared it with reference literature. We found that the high vascularisation is shared with other cerapodan dinosaurs with high tooth replacement rates, although homoeostasis may have also played a role in the development of this condition. Further evidence is needed to appreciate the macroevolutionary significance of these findings.

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Stegosaurs are a small but iconic clade of ornithischian dinosaurs. They and their sister taxa, the ankylosaurs, formed the clade Eurypoda which means ‘broad-footed’. Here, we describe a stegosaur from the Upper Jurassic Qigu Formation of Xinjiang, China, based on an associated partial skeleton that includes axial, pectoral girdle, pelvic girdle, limb and armor elements. It can be diagnosed as a new taxon, Angustungui, based on numerous autapomorphies. Some morphologies of Angustungui are more similar to the taxa from Europe, Africa and North America than to those from Asia. Our phylogenetic analysis recovers it as the sister taxon of Loricatosaurus. More importantly, the narrow and claw-shaped ungual of Angustungui proves that Eurypoda, at least stegosaur, has claw-shaped unguals. Besides, we revised the character scores for Chinese stegosaurs based on observations of the specimens.Competing Interest StatementThe authors have declared no competing interest.

Allosaurus Marsh, 1877 is one of the most iconic theropods of the Late Jurassic of USA and Portugal. However,
since the first description the genus was used as taxonomical wastebasket to which several species were
described. We revisit three type specimens, Allosaurus fragilis YPM 1930, A. atrox YPM 1890 and A. ferox USNM
2315. We interpret the vertebral material of A. atrox and support it as a junior synonym of A. fragilis, and A. ferox
as Allosaurus indet. rather than A. fragilis.

Turiasauria is a clade of basal sauropod dinosaurs hitherto only known from the Middle Jurassic (Bathonian) to the Lower Cretaceous (Valanginian). A new find of a shed tooth crown from the Lower Jurassic (Pliensbachian), Halse Formation of Bornholm, Denmark, is spoon-like, asymmetrical, and heart-shaped, which identifies the tooth as turiasaurian, pushing the origin of the Turiasauria some 17 My back into the Lower Jurassic. This suggests a North Pangean/Laurasian origin of the turiasaurian clade, which then, during the Middle to Late Jurassic, dispersed through Europe, India, and Africa, with their latest representatives found in the Early Cretaceous of England and North America. Furthermore, this is the first record of a sauropod from the Pliensbachian in Europe.

Iguanodontia is a diverse clade of herbivorous ornithischian dinosaurs that were speciose and abundant during the Jurassic and Cretaceous. Although the monophyly of Iguanodontia is well supported, their internal relationships have sparked heated debate due to several phylogenetic paradigm shifts. Late Jurassic basally branching iguanodontians in particular are not well understood in terms of their systematic affinities and evolutionary relevance. Their fossil record in Europe is meager compared with North America, with only a few species currently recognized. Two taxa are currently known from the Upper Jurassic of England, the basally branching styracosternan Cumnoria prestwichii and the putative dryosaurid Callovosaurus leedsi. In the Upper Jurassic of Portugal, the styracosternan Draconyx loureiroi and the dryosaurid Eousdryosaurus nanohallucis are presently the only described basally branching iguanodontians. Here we report a new species of early diverging iguanodontian from the Upper Jurassic Lourinhã Formation of western-central Portugal. The new species is clearly distinguished from all other coeval taxa by an exclusive combination of characters that include a tibia with a cnemial crest that is directed craniolaterally and a fibular condyle that is angled at 90° with respect to the proximal epiphysis, a fibula with symmetrical proximal margins, and a reduced metatarsal I. The phylogenetic relationships of the Lourinhã iguanodontian were explored using maximum parsimony and Bayesian inference. The two analyses recover the Lourinhã iguanodontian as an indeterminate dryomorphan, with more precise affinities precluded due to the current available material. Body size is estimated between 3 and 4 meters for the holotype specimen, adding to the diversity of small ornithopods already recognized in the paleoichnological record of the Lourinhã Formation. http://zoobank.org/urn:lsid:zoobank.org:pub:5F4D52D0-0F0B-4809-8561-BE58C7C97D45

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.

ABSTRACTHerein we describe phytosaurs from thin fluvial overbank sandstones of the Upper Triassic Malmros Klint Formation of the Fleming Fjord Group (central East Greenland). The new sample includes more than 150 disarticulated bones and teeth from small to large specimens belonging to at least four individuals. The fossils mostly consist of teeth and postcranial elements and permit the recognition of a new species of Mystriosuchus, M. alleroq, diagnosed by an L-shaped quadratojugal whose anterior suture trends anterodorsally and a tripartite degree of heterodonty. Humeral diaphyseal histology of one specimen reveals a fairly compact cortex that surrounds a cancellous medullary region followed by a remodeling zone containing scattered secondary osteons. Primary bone tissue is parallel-fibred with a moderate to low vascular density. The cortex is cyclically interrupted by distinct growth marks indicating a seasonal environment. A change in growth rate from moderate to low is documented within the outer cortex, indicating that at least this individual was close to somatic maturity. Mystriosuchus has formerly been known as an exclusively European taxon. The new findings support the European faunal influence in East Greenland during the Late Triassic inferred from other taxa such as temnospondyls and archosaurs. The mid-late Norian age of European Mystriosuchus suggests an additional age constraint for the vertebrate-bearing portion of the Malmros Klint Formation.

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The geochemical signatures of dinosaur eggshells represent well-established proxies in paleoenvironmental and paleobiological research. The variable sampling procedures reported in the literature, however, deserve attention. In order to evaluate the impact of different sampling methodologies on carbon and oxygen isotope and elemental concentrations, grinding was contrasted with drilling to extract powder samples from eggshell fragments collected at several locations. Eggshell data were further contrasted with surface materials, encasing matrix and compared with independent proxies using petrographic and elemental techniques. Iron and manganese elemental concentrations revealed an enrichment sequence depending on the sampling strategy for the same eggshell fragment. This pattern can be mistaken for a variable state of preservation. In contrast, carbon and oxygen isotope values exhibited only subtle differences and lacked clear trends. This suggests that isotope data are less susceptible to different methodological approaches. It is shown that drilling offers a wider range of possibilities compared to grinding (e.g., faster and less destructive). Additionally, drilled powder samples can confidently be used for elemental and isotope analysis, excluding contamination, thus providing a more accurate set of proxy data from eggshell archives.

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Abstract We present the first detailed braincase anatomical description and neuroanatomical study of Portugalosuchus azenhae, from the Cenomanian (Late Cretaceous) of Portugal. This eusuchian crocodylomorph was originally described as a putative Crocodylia and one of the oldest representatives of this clade; however, its phylogenetic position remains controversial. Based on new data obtained from high resolution Computed Tomography images (by micro-CT scan), this study aims to improve the original description of this taxon and also update the scarce neuroanatomical knowledge of Eusuchia and Crocodylia from this time interval, a key period to understand the origin and evolution of these clades. The resulting three-dimensional models from the CT data allowed a detailed description of its well-preserved neurocranium and internal cavities. Therefore, it was possible to reconstruct the cavities of the olfactory region, nasopharyngeal ducts, brain, nerves, carotid arteries, blood vessels, paratympanic sinus system and inner ear, which allowed to estimate some neurosensorial capabilities. By comparison with other crocodylomorphs, these analyses showed that Portugalosuchus, back in the Cenomanian, already displayed an olfactive acuity, sight, hearing and cognitive skills within the range of that observed in other basal eusuchians and crocodylians, including extant species. In addition, and in order to test its disputed phylogenetic position, these new anatomical data, which helped to correct and complete some of the original observations, were included in one of the most recent morphology-based phylogenies. The position of Portugalosuchus differs slightly from the original publication since it is now located as a “thoracosaurid” within Gavialoidea, but still as a crocodylian. Despite all this, to better contrast these results, additional phylogenetic analyses including this new morphological character coding together with DNA data should be performed.

An incomplete, yet remarkably-sized dentated rostrum and associated partial cervical vertebrae of a pterosaur (ML 2554) were recently discovered from the Late Jurassic (Late Kimmeridgian-Early Tithonian) Lourinhã Formation of Praia do Caniçal, of central west Portugal. This specimen exhibits features such as a spatulated anterior expansion of the rostrum, robust comb-like dentition, and pronounced rims of the tooth alveoli, indicating gnathosaurine affinities. Based on its further unique tooth and dentary morphology, a new genus and species, \textit{Lusognathus almadrava} gen. et spec. nov., is proposed, making this the first named pterosaur species found within Portugal. The presence of this taxon adds yet another element to the fluvio-deltaic lagoonal environment that has been suggested as representative of the Lourinhã Formation in the Late Jurassic, further contributing to the diversity and distribution of gnathosaurines worldwide.

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O sítio de Silveirinha é uma das localidades de mamíferos mais conhecidas da Paleontologia do Cenozoico de Portugal e da Europa em geral. Graças à sua rica e diversificada associação de mamíferos, com mais de 30 taxa, foi posicionado no Eocénico inferior (início do Ypresiano, MP7, ca. 55,8 M.a.), sendo o local mais antigo da Europa desta Época, devido à presença única de taxa típicos do Paleocénico superior, juntamente com outras espécies já características do Eocénico inferior. Este estudo irá rever o material de pequenos mamíferos deste sítio, conservado na coleção clássica da Universidade Nova de Lisboa, a fim de fazer uma actualização taxonómica à luz das publicações mais recentes.

Ostriches are known to be the fastest bipedal animal alive; to accomplish such an achievement, their anatomy evolved to sustain the stresses imposed by running at such velocities. Ostriches represent an excellent case study due to the fact that their locomotor kinematics have been extensively studied for their running capabilities. The shape and structure of ostrich bones are also known to be optimized to sustain the stresses imposed by the body mass and accelerations to which the bones are subjected during movements. This study focuses on the limb bones, investigating the structure of the bones as well as the material properties, and how both the structure and material evolved to maximise the performance while minimising the stresses applied to the bones themselves. The femoral shaft is hollowed and it presents an imbricate structure of fused bone ridges connected to the walls of the marrow cavity, while the tibial shaft is subdivided into regions having different mechanical characteristics. These adaptations indicate the optimization of both the structure and the material to bear the stresses. The regionalization of the material highlighted by the mechanical tests represents the capability of the bone to adapt to external stimuli during the life of an individual, optimizing not only the structure of the bone but the material itself.

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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.

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.

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.

{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.}

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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

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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.

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