Asociación de cefalópodos y secuencias deposicionales en el Cenomaniense superior y Turoniense inferior de la Península Ibérica (España y Portugal)

The comparison and correlation of the biostratigraphic successions identified in the upper Cenomanian and lower Turonian of the Iberian Trough (IT, Spain) and the Western Portuguese Carbonate Platform (WPCP, Portugal) allows differentiating nine cephalopod assemblages (1 to 9), with notably different taxa, and two (3rd order) depositional sequences (A and B). Some of these main intervals can be divided in minor ones, such as assemblage 4 (in 41 and 42) and sequence B (in B1 and B2). Assemblages 1 to 3 are related with sequence A, and assemblage 4 to 9 with sequence B (specifically, 4 to 6 with B1, and 7 to 9 with B2). The analysis and interpretation of these biostratigraphic data allows us to infer certain palaeoecologic turnovers that happened in the studied basins, both with external origin or due to local tectonic and palaeogeographical changes. Though partially altered by hypoxic phenomena (especially the sequence B1, assemblage 4) and local tectonics (mainly in the WPCP), in each of these cycles there were events of extinction of the cephalopods from shallow environments and survival of those from pelagic or deep environments, of settling of new environments, and of adaptation to them caused, successively, by intervals of low, ascending and high sea-level.La comparación y correlación de las sucesiones bioestratigráficas identificadas en el Cenomaniense superior y Turoniense inferior del Surco Ibérico (IT, España) y la Plataforma Carbonatada Occidental Portuguesa (WPCP, Portugal) permiten diferenciar nueve asociaciones de cefalópodos (1 a 9), con taxones notablemente diferentes, y dos secuencias deposicionales principales (3er orden) (A y B). Algunos de estos intervalos principales pueden dividirse en secundarios, como la Asociación 4 (en 41 and 42) y la Secuencia B (en B1 y B2). Las asociaciones 1 a 3 pueden se pueden relacionar con la secuencia A, y la asociación 4 a 9 con la secuencia la B (concretamente, 4 a 6 con B1, y 7 a 9 con B2). El análisis y la interpretación de estos datos bioestratigráficos permiten deducir ciertos cambios paleoecológicos sucedidos en las cuencas estudiadas, tanto de origen externo como debidos a la tectónica local ó a cambios paleogeográficos. Aunque parcialmente alterados por fenómenos de hipoxia (especialmente la secuencia B1, asociación 4) y de tectónica local (principalmente en el WPCP), en cada uno de estos ciclos se produjeron fenómenos de extinción de los cefalópodos de medios someros y de supervivencia de los de ambientes pelágicos ó profundos, de colonización de nuevos espacios, y de adaptación a los mismos provocados, sucesivamente, por intervalos de nivel de mar bajo, ascendente y alto

Moluscos del yacimiento paleontológico de "Lo Hueco" (Cretácico Superior, Cuenca, España): Implicaciones paleoambientales y secuenciales

In the exceptional site of "Lo Hueco" (Cuenca, Spain) more than 8500 macroremains of plants, invertebrates and vertebrates, including titanosaur sauropod dinosaurs, have been collected in a succession of Upper Cretaceous "Garumn" facies. This work describes the molluscs found together, interpreting their palaeoenvironmental and sequential meaning. The sample is comparatively scarce due to the urgency of the excavation, and to constraints of the preservational scenario, seemingly not ideal for the fossilization of carbonated remains. Thus, the absence of well preserved shells has motivated the use of open nomenclature. Bivalves are recorded by unarticulated marly mudstone moulds of Margaritifera sp., Anodonta sp., ?Corbicula sp. and Pisidium sp., and most gastropods by gypsum moulds of Faunus sp. This association indicates a typical freshwater palaeofauna, where the presence of Melanopsidae gastropods can suggest the sporadic influence of moderately brackish-water episodes. These data confirm previous palaeoenvironmental interpretations proposed for the site. Additionally, the presence of the terrestrial gastropod Palaeocyclophorus sp. in underlying beds with high proportion of vegetal terrestrial organic matter, and situated over an important erosive discordance, has allowed to locate the beginning of the depositional sequence of "Lo Hueco".En el excepcional yacimiento paleontológico de "Lo Hueco" (Cuenca, España) se han obtenido más de 8500 macrorrestos de plantas, invertebrados y vertebrados, incluyendo dinosaurios saurópodos titanosaurios, en una sección del Cretácico Superior en facies "Garumn". El presente trabajo describe los moluscos recogidos, interpretando su significado paleoambiental y secuencial. La muestra obtenida resulta relativamente reducida debido a la urgencia de la excavación, y a que las condiciones diagenéticas posiblemente no han favorecido la preservación de restos carbonatados. En consecuencia, la ausencia de conchas bien preservadas ha obligado a la utilización de nomenclatura abierta. Los bivalvos identificados se encuentran representados por moldes margosos desarticulados de Margaritifera sp., Anodonta sp., ?Corbicula sp. y Pisidium sp., y la mayoría de los gasterópodos por moldes de yeso de Faunus sp. Esta asociación corresponde a una típica paleofauna de agua dulce, en la que la presencia de gasterópodos melanópsidos parece sugerir la influencia esporádica de episodios de agua salobre. Estos datos confirman las interpretaciones paleoambientales previas propuestas para el yacimiento. Adicionalmente, la presencia del gasterópodo terrestre Palaeocyclophorus sp. en niveles infrayacentes con una elevada proporción de materia orgánica vegetal, situados sobre una importante discordancia erosiva, ha permitido localizar el inicio de la secuencia deposicional correspondiente a "Lo Hueco"

LOWER CRETACEOUS DINOSAUR TRACKS FROM THE SEASHORE AREAS OF

Trata-se da descoberta de uma pista na praia de Parede, uma famosa área turística localizada a cerca de 20 km a partir de Lisboa, perto de Cascais, onde um dos poucos tracksites dinossauro conhecido do Cretáceo Inferior de Portugal podem ser observados. Uma visão geral da pista quase horizontal nível situado em frente ao "Bar Terraço Xana" põe em evidência uma sequência principal de pegadas interpretado como um saurópode trackway. Tem uma grande importância pedagógica - turística pela grande facilidade de acesso e observação

Dinosaur tracks from the Early Cretaceous (Albian) of Parede (Cascais, Portugal): new contributions for the sauropod palaeobiology of the Iberian Peninsula

A recently discovered Early Cretaceous (early late Albian) dinosaur tracksite at Parede beach (Cascais, Portugal) reveals evidence of dinoturbation and at least two sauropod trackways. One of these trackways can be classified as narrow-gauge, which represents unique evidence in the Albian of the Iberian Peninsula and provides for the improvement of knowledge of this kind of trackway and its probable trackmaker, in an age when the sauropod record is scarce. These dinosaur tracks are preserved on the upper surface of a marly limestone bed that belongs to the Galé Formation (Água Doce Member, middle to lower upper Albian). The study of thin-sections of the beds C22/24 and C26 in the Parede section has revealed a microfacies composed of foraminifers, radiolarians, ostracods, corals, bivalves, gastropods, and echinoids in a mainly wackestone texture with biomicritic matrix. These assemblages match with the lithofacies, marine molluscs, echinids, and ichnofossils sampled from the section and indicate a shallow marine, inner shelf palaeoenvironment with a shallowing-upward trend. The biofacies and the sequence analysis are compatible with the early late Albian age attributed to the tracksite. These tracks and the moderate dinoturbation index indicate sauropod activity in this palaeoenvironment. Titanosaurs can be dismissed as possible trackmakers on the basis of the narrow-gauge trackway, and probably by the kidney-shaped manus morphology and the pes-dominated configuration of the trackway. Narrow-gauge sauropod trackways have been positively associated with coastal palaeoenvironments, and the Parede tracksite supports this interpretation. In addition, this tracksite adds new data about the presence of sauropod pes-dominated trackways in cohesive substrates. As the Portuguese Cretaceous sauropod osteological remains are very scarce, the Parede tracksite yields new and relevant evidence of these dinosaurs. Furthermore, the Parede tracksite is the youngest evidence of sauropods in the Portuguese record and some of the rare evidence of sauropods in Europe during the Albian. This discovery enhances the palaeobiological data for the Early Cretaceous Sauropoda of the Iberian Peninsula, where the osteological remains of these dinosaurs are relatively scarce in this region of southwestern Europe. Therefore, this occurrence is also of overall interest due to its impact on Cretaceous Sauropoda palaeobiogeography.El reciente descubrimiento de huellas de dinosaurios del Cretácico Inferior (inicio del Albiense tardío) en la playa de Parede (Cascais, Portugal) ha revelado evidencias de dinoturbación y al menos dos rastros de saurópodos. Uno de ellos puede clasificarse como estrecho y representa la única evidencia de este tipo de rastros en el Albiense de la Península Ibérica. Estos nuevos datos permiten mejorar el conocimiento tanto de este tipo de rastros como de su posible productor, en una edad en la que el registro de saurópodos es escaso. Las huellas de dinosaurios se localizan en un nivel de caliza margosa perteneciente a la Formación Galé (Miembro Água Doce, Albiense medio-base del superior). El estudio de láminas delgadas de los niveles C22/24 y C26 de la sección estratigráfica de Parede ha mostrado ricas biomicrofacies compuestas por foraminíferos, radiolarios, ostrácodos, corales, bivalvos, gasterópodos y equinoideos, mayoritariamente en textura “wackestone” con matriz biomicrítica. Estas asociaciones coinciden con las litofacies, los moluscos marinos, los equínidos y los icnofósiles obtenidos en la sección, y corresponden a un paleoambiente marino somero de plataforma interna con tendencia somerizante hacia techo. Las biofacies y el análisis secuencial resultan compatibles con la edad del inicio del Albiense tardío atribuida al yacimiento. Estas huellas y el moderado índice de dinoturbación son indicadores de la actividad de saurópodos en este paleoambiente. En base a la estrechez del rastro, probablemente a la morfología arriñonada/semicircular de la mano y al hecho que se trata de un rastro “pes-dominated”, pueden descartarse a los titanosaurios como posibles productores. Los rastros estrechos han sido relacionados con paleoambientes costeros, y el yacimiento de Parede sustenta esta interpretación. Además, este yacimiento proporciona nuevos datos sobre la presencia de rastros de tipo “pes-dominated” en substratos cohesivos. Los restos osteológicos de saurópodos cretácicos portugueses son muy escasos, aportando el yacimiento de Parede una nueva y relevante evidencia de estos dinosaurios. Asimismo, el yacimiento de Parede constituye el hallazgo más moderno de saurópodos en el registro portugués, y una de las pocas evidencias de saurópodos en Europa durante el Albiense. Este descubrimiento incrementa los datos paleobiogeográficos de Sauropoda en el Cretácico Inferior en la Península Ibérica, en un período de tiempo en el que los restos de estos dinosaurios son escasos en esta región del Suroeste de Europa. Por tanto, este hallazgo muestra un elevado interés debido a su trascendencia para la paleobiogeografía de Sauropoda en el Cretácico

Depositional sequences and ammonoid assemblages in the upper Cenomanian-lower Santonian of the Iberian Peninsula (Spain and Portugal)

A clear relationship exists between eustatic sea-level rises and falls recorded as cyclical depositional sequences and ammonite faunas during the Cenomanian-Santonian in the Iberian and West Portuguese basins. Most of the faunal turnovers correlate with stratigraphic intervals related to marine transgressions, maximum flooding of the shelf (locally associated to anoxic events), and marine regressions. Specifically, within each depositional sequence, three distinct and identical events of morphological change occur, involving ammonoids belonging to different groups. Transgressive sediments are characterized by moderately ornamented, inflated and evolute morphologies, which are replaced by smooth, involute and compressed oxycones (the most hydrodynamic shells) during maximum flooding (and to a lesser extent at the early highstand) of the sequences. The latter morphologies in turn are replaced by coarsely ornamented and evolute shells during late highstands. We conclude that ammonoid faunal analysis can be used to trace sea-level changes and provides an additional tool for sequence stratigraphy

Synchrotron X-ray microdiffraction to study dental structures in Cretaceous crocodylomorphs

Synchrotron radiation X-ray microdiffraction (SR-μXRD) has been applied for the first time as a fundamental method of analysis to unveil crocodilian teeth growth and development. Teeth from a fossil crocodylomorph from the Upper Cretaceous site of Lo Hueco (Spain) and a modern crocodylian from the living species Crocodylus niloticus have been analysed. Both samples have been studied through Polarized Light Microscopy, Scanning Electron Microscopy coupled with Energy Dispersive X-Ray Spectroscopy, Confocal Raman Spectroscopy, and SR-μXRD. Significant differences have been found in hydroxyapatite (HA) crystallite sizes and texture, and the evolution of these two features along teeth depth. The main differences observed in crystallite size are related to postdepositional processes and/or the environmental and functional pressures of teeth during crocodylomorph life, very different from that of the modern specimen. Regarding the crystalline texture in the tooth enamel, it can be linked to teeth functionality during crocodilian life, causing the directed growth of HA crystallites due to the mechanical stress to which they are subjectedThis work was funded by the projects PGC2018-099405-B-100 (Ministerio de Ciencia, Innovacion y Universidades); HAR2017- 82755-P, HAR2016-78036-P, HAR2016-74846-P, HAR2017-83004-P, CGL2015-66604, CGL2015-68363 and MAT2015-67593-P (Ministerio de Economía y Competitividad, Spain); and 201860E127 (CSIC

Compreender as Geociências através da Arte: a pintura naturalista como recurso didático no ensino e na divulgação do Património Geológico

UID/GEO/50019/2019 UID/Multi/00611/2020 POCI-01-0145-FEDER-006922 UIDB/04035/2020Comunicar Ciências Naturais ao analisar obras de coleções de Arte, quer no contexto de uma sala de aula, quer no de um museu, promove o conhecimento sobre estes assuntos e a compreensão de acontecimentos com causas naturais que frequentemente afetam as populações. Com esta interação espera-se conseguir motivar públicos diversos a procurarem compreender estes eventos e a visitarem museus de História Natural e, por sua vez, estimular públicos mais votados às ciências a visitarem museus de Arte. Por outro lado, atividades de Geoturismo responsável, que aproximem o público de geossítios representados nas obras de Arte que observou, permitem-lhe conhecer e compreender o Património Natural, em particular o geológico, e participar ativamente nas estratégias de geoconservação.publishersversionpublishe

The biota of the Upper Cretaceous site of Lo Hueco (Cuenca, Spain)

The Late Cretaceous (Campanian-Maastrichtian) fossil site of Lo Hueco was recently discovered close to the village of Fuentes (Cuenca, Spain) during the cutting of a little hill for installation of the railway of the Madrid-Levante high-speed train. To date, it has yielded a rich collection of well-preserved Cretaceous macrofossils, including plants, invertebrates, and vertebrates. The recovered fossil assemblage is mainly composed of plants, molluscs (bivalves and gastropods), actinopterygians and teleosteans fishes, amphibians, panpleurodiran (bothremydids) and pancryptodiran turtles, squamate lizards, eusuchian crocodyliforms, rhabdodontid ornithopods, theropods (mainly dromaeosaurids), and titanosaur sauropods. This assemblage was deposited in a near-coast continental muddy floodplain crossed by distributary sandy channels, exposed intermittently to brackish or marine and freshwater flooding as well as to partial or total desiccation events.The Konzentrat-Lagerstatt of Lo Hueco constitutes a singular accumulation of fossils representing individuals of some particular lineages of continental tetrapods, especially titanosaurs, eusuchians and bothremydid turtles. In the case of the titanosaurs, the site has yielded multiple partial skeletons in anatomical connection or with a low dispersion of their skeletal elements. A combination of new taxa, new records of taxa previously known in the Iberian Peninsula, and relatively common taxa in the European record compose the Lo Hueco biota. The particular conditions of the fossil site of Lo Hueco and the preliminary results indicate that the analysis of the geological context, the floral and faunal content, and the taphonomical features of the site provide elements that will be especially useful for reassess the evolutionary history of some lineages of European Late Cretaceous reptiles.Peer reviewe

Neurocranial osteology and neuroanatomy of a late Cretaceous Titanosaurian Sauropod from Spain (Ampelosaurus sp.)

Titanosaurians were a flourishing group of sauropod dinosaurs during Cretaceous times. Fossils of titanosaurians have been found on all continents and their remains are abundant in a number of Late Cretaceous sites. Nonetheless, the cranial anatomy of titanosaurians is still very poorly known. The Spanish latest Cretaceous locality of "Lo Hueco" yielded a relatively well preserved, titanosaurian braincase, which shares a number of phylogenetically restricted characters with Ampelosaurus atacis from France such as a flat occipital region. However, it appears to differ from A. atacis in some traits such as the greater degree of dorsoventral compression and the presence of proatlas facets. The specimen is, therefore, provisionally identified as Ampelosaurus sp. It was CT scanned, and 3D renderings of the cranial endocast and inner-ear system were generated. Our investigation highlights that, although titanosaurs were derived sauropods with a successful evolutionary history, they present a remarkably modest level of paleoneurological organization. Compared with the condition in the basal titanosauriform Giraffatitan brancai, the labyrinth of Ampelosaurus sp. shows a reduced morphology. The latter feature is possibly related to a restricted range of head-turning movementsThis is a contribution to the research project CGL2009-12143 (Ministerio de Economía y Competitividad, Madrid), of which FK, who is currently supported by the Ramón y Cajal Program, is Principal Investigator. LMW and RCR acknowledge funding support from the United States National Science Foundation (IBN-9601174, IBN-0343744, IOB-0517257, IOS-1050154) and the Ohio University Heritage College of Osteopathic Medicine. The Ohio Supercomputing Center also provided suppor

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

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