38 research outputs found

    Paleoneuroanatomy of the European lambeosaurine dinosaur Arenysaurus ardevoli

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    The neuroanatomy of hadrosaurid dinosaurs is well known from North America and Asia. In Europe only a few cranial remains have been recovered that include the braincase. Arenysaurus is the first European endocast for which the paleoneuroanatomy has been studied. The resulting data have enabled us to draw ontogenetic, phylogenetic and functional inferences. Arenysaurus preserves the endocast and the inner ear. This cranial material was CT scanned, and a 3D-model was generated. The endocast morphology supports a general pattern for hadrosaurids with some characters that distinguish it to a subfamily level, such as a brain cavity that is anteroposteriorly shorter or the angle of the major axis of the cerebral hemisphere to the horizontal in lambeosaurines. Both these characters are present in the endocast of Arenysaurus. Osteological features indicate an adult ontogenetic stage, while some paleoneuroanatomical features are indicative of a subadult ontogenetic stage. It is hypothesized that the presence of puzzling mixture of characters that suggest different ontogenetic stages for this specimen may reflect some degree of dwarfism in Arenysaurus. Regarding the inner ear, its structure shows differences from the ornithopod clade with respect to the height of the semicircular canals. These differences could lead to a decrease in the compensatory movements of eyes and head, with important implications for the paleobiology and behavior of hadrosaurid taxa such as Edmontosaurus, Parasaurolophus and Arenysaurus. The endocranial morphology of European hadrosaurids sheds new light on the evolution of this group and may reflect the conditions in the archipelago where these animals lived during the Late CretaceousPeer ReviewedPostprint (published version

    A new ornithopod dinosaur from the Santonian of Northern Patagonia (Rincón de los Sauces, Argentina)

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    In recent decades, the Argentinian ornithopod record – which includes eight species that have been described – has increased as a result of the discovery of diverse new bone remains from the Upper Cretaceous. The area near the town of Rincón de los Sauces (Neuquén Province) presents rich fossiliferous outcrops that have provided new ornithopod remains. These bones are from two units: the Plottier and Bajo de la Carpa formations. In the latter, several isolated postcranial bones and a partial articulated skeleton (MAU-Pv-CO-596) have been found. The holotype of Mahuidacursor lipanglef gen. et sp. nov. (MAU-Pv-CO-596) comes from the Cerro Overo site (Santonian, Upper Cretaceous). The skeleton preserves elements from the cervical and dorsal series, the pectoral girdle and the right forelimb. It corresponds to a medium-bodied ornithopod with a gracile general appearance. Histological analysis suggests that the specimen was a sexually mature but not fully grown individual. Some distinctive characters present in Mahuidacursor, such as the strongly bowed humeral shaft and the weakly developed deltopectoral crest, are shared with other South American basal ornithopods. A phylogenetic analysis including Mahuidacursor within a large ornithischian dataset was performed. The results show Mahuidacursor to be a basal ornithopod recovered within a polytomy along with Notohypsilophodon and the clade Elasmaria (Talenkauen + Macrogryphosaurus)

    Presence of diminutive hadrosaurids (Dinosauria: Ornithopoda) in the Maastrichtian of the south-central Pyrenees (Spain)

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    In recent years a rich and diverse fauna of hadrosaurid dinosaurs has been described in the Upper Cretaceous of the Pyrenees. Recent fieldwork carried out in the upper Maastrichtian levels of the Tremp Formation, in the south-central Pyrenees (province of Huesca, northeastern Spain), has allowed us to recover diminutive fossil bones referable to hadrosaurid dinosaurs. To date, small-sized specimens had not been reported in the area. The remains consist of small vertebrae and fragmentary long bones found in a relatively small area, so it is assumed that they probably belong to individuals of a single population. A morphological examination and a histological study reveal that they represent specimens of advanced ontogenetic stage and allow the identification of an undescribed taxon of small-bodied hadrosaurids. In other parts of Europe, discoveries of small dinosaurs have been linked to insularity. These findings bring to light the smallest hadrosaurid known in Europe to date.This paper forms part of the projects CGL2010-16447, CGL2010-18851/BTE and CGL2013-47521-P, subsidized by the Spanish Ministerio de Economia y Competitividad and the European Regional Development Fund. In addition the Government of Aragon ("Grupos Consolidados'' and "Direccion General de Patrimonio Cultural'') has subsidized the fieldwork. The second author received a postdoctoral grant from the Ministerio de Ciencia, Tecnologia e Innovacion Productiva del Consejo Nacional de Investigaciones Cientificas y Tecnicas (CONICET). The study of the specimens housed at the NHM (London) has been suported by a study grant funded by the Caja de Ahorros de la Inmaculada (Zaragoza) to the second author in 2006. The manuscript has greatly benefited from reviews by Edina Prondvai (MTA-ELTE Lendulet Dinosaur Research Group, Budapest) and David B. Weishampel (Johns Hopkins University - School of Medicine, Baltimore). Special thanks also are owed to J.I. Ruiz-Omenaca (Museo Jurasico de Asturias-MUJA, Colunga) and Xabier Pereda-Suberbiola (Universidad del Pais Vasco, UPV/EHU, Bilbao) for providing helpful information on Nopcsa's work. Rupert Glasgow corrected the English text.Company Rodríguez, J.; Cruzado Caballero, P.; Canudo, J. (2015). Presence of diminutive hadrosaurids (Dinosauria: Ornithopoda) in the Maastrichtian of the south-central Pyrenees (Spain). Journal of Iberian Geology. 41(1):71-81. doi:10.5209/rev_JIGE.2015.v41.n1.48656718141

    Bioerosion and palaeoecological association of osteophagous insects in the Maastrichtian dinosaur Arenysaurus ardevoli

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    Bioerosions produced by the osteophagous diet of animals that fed on dinosaur bones are very scarce in the European fossil record. Herein we present bioerosion on hadrosaurid remains from the Maastrichtian Tremp Formation of the Pyrenean Basin, which is only the second such case recorded from the Iberian-Occitan Plate besides a sauropod from the Jurassic-Cretaceous of Valencia. The hadrosaurid fossil record is particularly rich in the Blasi sites of the Tremp Formation located in the municipality of Arén (Huesca, Spain). In this article, bones referred to the hadrosaurid Arenysaurus ardevoli from the Blasi-3 site are analysed to shed light on the palaeoenvironment and on the presence of a palaeoecological interaction between the hadrosaurid carcase and osteophagous tracemakers. Bioerosions recorded on the bones comprise tunnels, roundish holes, and straight notches, similar to the traces attributed to necrophagous insects (cf. Cuniculichnus seilacheri). Here, we record the first instance of the activity of these animals on dinosaur bones in the Upper Cretaceous of the Ibero-Occitan Plate. The results presented lead us to infer that the Arenysaurus bones were possibly transported by a storm or similar event to the Blasi-3 site, where they were exposed to post-mortem biotic interactions (eaten and partially decomposed by dermestid beetles) for a prolonged time period before they were completely buried. © 2021 The Authors. Lethaia published by John Wiley & Sons Ltd on behalf of Lethaia Foundatio

    La Cantalera: an exceptional window onto the vertebrate biodiversity of the Hauterivian-Barremian transition in the Iberian Peninsula.

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    La Cantalera is an accumulation site for fossil vertebrates consisting mainly of teeth and isolated postcranial remains. It has the greatest vertebrate biodiversity of any site from the Hauterivian-Barremian transition in the Iberian Peninsula. Up to now, 31 vertebrate taxa have been recognized: an osteichthyan (Teleostei indet.), two amphibians (Albanerpetonidae indet. and Discoglossidae indet.), a chelonian (Pleurosternidae? indet.), a lizard (Paramacellodidae? indet.), four crocodylomorphs (cf. Theriosuchus sp., Bernissartiidae indet., Goniopholididae indet., cf. Lisboasaurus sp.), two pterosaurs (Istiodactylidae? indet., Ornithocheiridae? indet.), four ornithopod dinosaurs (Iguanodontoidea indet., Hadrosauroidea? indet., “Hypsilophodontidae” indet., Rhabdodontidae? indet.), a thyreophoran (Polacanthidae indet.), a sauropod (Euhelopodidae indet.), eleven theropods (Carcharodontosauridae? indet., Baryonychinae indet., aff. Paronychodon sp., Maniraptora indet. 1-3, Dromaeosaurinae indet. 1-3, Velociraptorinae indet., Avialae? indet.) and three or four multituberculate mammals (Cantalera abadi, Eobaatar sp., Plagiaulacidae or Eobaataridae gen. et sp. indet., “Plagiaulacida” indet.). Nine ootaxa have also been distinguished at the site of La Cantalera. Oofamilies assigned to dinosaurs (Elongaloolithidae, Prismatoolithidae, cf. Spheroolithidae), to crocodiles (Krokolithidae) and eggshells of two oofamilies incertidae sedis are represented. This association is consistent with the record of bone and tooth remains from the site. La Cantalera was formed in a marshy environment where there was an intermittent body of water. The great majority of the vertebrate fossil remains lack evidence of transport, so the preserved association is a good representation of the vertebrate ecosystem in or around the marshy area of La Cantalera. The vertebrate association of La Cantalera displays certain differences with respect to those from lacustrine environments of the Hauterivian-Barremian transition of the Iberian Range. These differences include, for example, the absence of Chondrichthyes, the merely token presence of the osteichthyans, the scarcity of chelonians, the presence of exclusively multituberculate mammals, the lower diversity of sauropods and the greater diversity of theropods

    Magnetoestratigrafía del Cretácico Superior del sector Occidental de las Sierras Exteriores (Pirineo Occidental); implicaciones bioestratigráficas.

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    El Cretácico Superior del sector más Occidental de las Sierras Exteriores (Sa de Sto. Domingo) está escasamente representado en potencia pero presenta las facies más someras y transicionales donde se han recuperado recientemente restos de vertebrados fósiles (Osteichthyes, Chondrichthyes y Dinosauria), algunos de los cuales son de carácter continental. En este trabajo se presentan los resultados del análisis magnetoestratigráfico llevado a cabo en 4 secciones de pequeña potencia situadas entre los meridianos de San Felices y de Luesia (Prov. de Zaragoza). La magnetización característica de estas rocas es estable, primaria y muestra dos polaridades del campo magnético. La correlación tentativa entre perfiles, unida al conocimiento de las asociaciones de vertebrados existente en la cuenca de Graus-Tremp, permiten proponer una correlación preliminar que relacionaría los niveles fosilíferos con el cron C32n (Campaniense) y las facies Garum con los crones C29r, C29n y C28r (Maastrichtiense y Daniense) de la escala global de polaridad magnética. Esta correlación conlleva un hiato sedimentario durante el Maastrichtiense que deberá ser revisado en futuros estudios sedimentológicos

    Relict duck-billed dinosaurs survived into the last age of the dinosaurs in subantarctic Chile

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    In the dusk of the Mesozoic, advanced duck-billed dinosaurs (Hadrosauridae) were so successful that they likely outcompeted other herbivores, contributing to declines in dinosaur diversity. From Laurasia, hadrosaurids dispersed widely, colonizing Africa, South America, and, allegedly, Antarctica. Here, we present the first species of a duck-billed dinosaur from a subantarctic region, Gonkoken nanoi, of early Maastrichtian age in Magallanes, Chile. Unlike duckbills further north in Patagonia, Gonkoken descends from North American forms diverging shortly before the origin of Hadrosauridae. However, at the time, non-hadrosaurids in North America had become replaced by hadrosaurids. We propose that the ancestors of Gonkoken arrived earlier in South America and reached further south, into regions where hadrosaurids never arrived: All alleged subantarctic and Antarctic remains of hadrosaurids could belong to non-hadrosaurid duckbills like Gonkoken. Dinosaur faunas of the world underwent qualitatively different changes before the Cretaceous-Paleogene asteroid impact, which should be considered when discussing their possible vulnerability

    A New Crocodylian from the Late Maastrichtian of Spain: Implications for the Initial Radiation of Crocodyloids

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    The earliest crocodylians are known primarily from the Late Cretaceous of North America and Europe. The representatives of Gavialoidea and Alligatoroidea are known in the Late Cretaceous of both continents, yet the biogeographic origins of Crocodyloidea are poorly understood. Up to now, only one representative of this clade has been known from the Late Cretaceous, the basal crocodyloid Prodiplocynodon from the Maastrichtian of North America.The fossil studied is a skull collected from sandstones in the lower part of the Tremp Formation, in Chron C30n, dated at -67.6 to 65.5 Ma (late Maastrichtian), in Arén (Huesca, Spain). It is located in a continuous section that contains the K/P boundary, in which the dinosaur faunas closest to the K/P boundary in Europe have been described, including Arenysaurus ardevoli and Blasisaurus canudoi. Phylogenetic analysis places the new taxon, Arenysuchus gascabadiolorum, at the base of Crocodyloidea.The new taxon is the oldest crocodyloid representative in Eurasia. Crocodyloidea had previously only been known from the Palaeogene onwards in this part of Laurasia. Phylogenetically, Arenysuchus gascabadiolorum is situated at the base of the first radiation of crocodyloids that occurred in the late Maastrichtian, shedding light on this part of the cladogram. The presence of basal crocodyloids at the end of the Cretaceous both in North America and Europe provides new evidence of the faunal exchange via the Thulean Land Bridge during the Maastrichtian

    aHUS caused by complement dysregulation: new therapies on the horizon

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    Atypical hemolytic uremic syndrome (aHUS) is a heterogeneous disease that is caused by defective complement regulation in over 50% of cases. Mutations have been identified in genes encoding both complement regulators [complement factor H (CFH), complement factor I (CFI), complement factor H-related proteins (CFHR), and membrane cofactor protein (MCP)], as well as complement activators [complement factor B (CFB) and C3]. More recently, mutations have also been identified in thrombomodulin (THBD), an anticoagulant glycoprotein that plays a role in the inactivation of C3a and C5a. Inhibitory autoantibodies to CFH account for an additional 5–10% of cases and can occur in isolation or in association with mutations in CFH, CFI, CFHR 1, 3, 4, and MCP. Plasma therapies are considered the mainstay of therapy in aHUS secondary to defective complement regulation and may be administered as plasma infusions or plasma exchange. However, in certain cases, despite initiation of plasma therapy, renal function continues to deteriorate with progression to end-stage renal disease and renal transplantation. Recently, eculizumab, a humanized monoclonal antibody against C5, has been described as an effective therapeutic strategy in the management of refractory aHUS that has failed to respond to plasma therapy. Clinical trials are now underway to further evaluate the efficacy of eculizumab in the management of both plasma-sensitive and plasma-resistant aHUS

    Mortality and pulmonary complications in patients undergoing surgery with perioperative sars-cov-2 infection: An international cohort study

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    Background The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (740%) had emergency surgery and 280 (248%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (261%) patients. 30-day mortality was 238% (268 of 1128). Pulmonary complications occurred in 577 (512%) of 1128 patients; 30-day mortality in these patients was 380% (219 of 577), accounting for 817% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 175 [95% CI 128-240], p<00001), age 70 years or older versus younger than 70 years (230 [165-322], p<00001), American Society of Anesthesiologists grades 3-5 versus grades 1-2 (235 [157-353], p<00001), malignant versus benign or obstetric diagnosis (155 [101-239], p=0046), emergency versus elective surgery (167 [106-263], p=0026), and major versus minor surgery (152 [101-231], p=0047). Interpretation Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research
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