An overview of the lower cretaceous dinosaur tracksites from the mirambel formation in the iberian range (ne spain)

Up to now, the ichnological vertebrate record from the Barremian Mirambel Formation (NE Spain) has remained completely unknown despite the fact that osteological findings have been reported in recent years. Here we provide an overview of 11 new dinosaur tracksites found during a fieldwork campaign in the year 2011. The majority of these tracksites (seven) preserve small- to medium-sized tridactyl tracks here assigned to indeterminate theropods. Only one footprint presents enough characters to classify it as Megalosauripus isp. Ornithopod tracks identified as Caririchnium isp. and Iguanodontipodidae indet. and sauropod tracks are recorded at two tracksites. The footprints are preserved in a variety of paleoenvironmental conditions and thus display different kinds of preservation (true tracks, shallow undertracks, natural casts and undertrack casts). The ichnological record from the Mirambel Formation seems to be theropod dominated. This is a clear discrepancy with the osteological record identified in this formation, which shows a predominance of ornithopod dinosaurs

Enigmatic tracks of solitary sauropods roaming an extensive lacustrine megatracksite in Iberia

Sauropod remains are abundant on the Iberian Peninsula across the Jurassic-Cretaceous transition. Where the osteological record shows a high diversity of this kind of dinosaur, the ichnological findings are mainly limited to sauropod tracks characterized by kidney-shaped manus (with or without pollex impressions) and pes impressions with three claw imprints oriented laterally. Here, we present a new sauropod ichnotaxon, Iniestapodus burgensis, found at several exposures within the Las Sereas megatracksite (Burgos, Spain). These are preserved within lacustrine limestone strata of the Rupelo Formation (Tithonian-Berriasian). Iniestapodus burgensis is characterized by: semicircular manus tracks with small pollex impressions; unusual tetradactyl pes tracks with evidence of four claws oriented anteriorly (I-II) and laterally (III-IV), of variable sizes (short claw I and IV impressions, claw II and III being the largest). The combination of features and comparison with the osteological record allows us to propose a non-titanosaurian titanosauriform as a possible trackmaker. All the Iniestapodus tracks are represented by at least two different size classes of small and medium-sized individuals, and their trackways show different multidirectional orientations. The paleoenvironmental and paleoecological data suggest that Iniestapodus trackmakers were solitary individuals, likely representing different age classes, that crossed and used the Las Sereas shallow lacustrine-palustrine areas as their preferred habitat

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

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

Sauropod trackways of the Iberian Peninsula: palaeoetological and palaeoenvironmental implications

More than a hundred sauropod tracksites, ranging in age from Middle Jurassic (Bathonian) to Late Cretaceous (Maastrichtian), are repor­ted from the Iberian Peninsula (Spain and Portugal). Sauropod trackway orientation patterns throughout an entire geographic area such as the Iberian Peninsula and over different time periods may provide new data about the palaeoecology and behavioural patterns of sauropods. The studied tracksites exhibit two main trackway orientation patterns, directional and random, indicating different behaviours in grega­rious or solitary (milling) individuals. Gregarious behavioural patterns are mainly observed within Parabrontopodus/Breviparopus-like and Brontopodus-like ichnotypes of a single size class (either small or medium-sized), indicating age segregation. Among the gregarious sauropods the former ichnotype is linked with inland environments, while the latter is mainly linked with coastal environments. Solitary trackways are mainly of medium-sized to large individuals, are also linked with both inland (Parabrontopodus/Breviparopus-like) and coastal environments (Parabrontopodus/Breviparopus-like, Brontopodus-like), and belong to the above-mentioned ichnotypes as well as to Polyonyx-like ichnotypes. Thus, no obvious link between gregarious behaviour and the palaeoenvironmental setting can be inferred from the sauropod track record of the Iberian Peninsula. Nonetheless, sauropod trackways showing titanosauriform characters (Brontopodus-like) are more common in coastal environments, contrary to what might be expected given this group’s apparent taxonomic preference for inland environments.El registro Ibérico (España y Portugal) de icnitas de saurópodos está representado por más de cien yacimientos cuya edad varía desde el Jurásico Medio (Batoniense) al Cretácico Superior (Maastrichtiense). El estudio de la orientación de los rastros, en un área determinada como la Península Ibérica y en diferentes edades, nos ha permitido obtener nuevos datos sobre el comportamiento de los saurópodos. Los rastros de los yacimientos estudiados presentan dos patrones de movimiento distintos, direccionales y aleatorios, que reflejan distintos com­portamientos en individuos gregarios o solitarios (deambulantes). El patrón que indica comportamiento gregario se observa en los icnotipos “Parabrontopodus/Breviparopus-like” y “Brontopodus-like” en saurópodos del mismo tamaño (pequeño o medio), lo que indica segregación por edad. El primer icnotipo se ha conservado en sedimentos depositados en ambientes terrestres mientras que el segundo lo hace fundamen­talmente en ambientes costeros. Los rastros solitarios son, en su mayoría, de saurópodos de tamaño medio o grande, conservados tanto en medios terrestres (“Parabrontopodus/Breviparopus-like”), como costeros (“Parabrontopodus/Breviparopus-like” y “Brontopodus-like”) y pertenecen a los dos icnotipos mencionados anteriormente y a un tercero: “Polyonyx-like”. Por lo tanto, no hay una significativa influencia paleoambiental en el registro del comportamiento gregario de los saurópodos ibéricos. Sin embargo, los rastros saurópodos que muestran caracteres Titanosauriformes (Brontopodus-like) son más frecuentes en los medios costeros de la Península Ibérica. Estos resultados son diferentes a los expuestos por otros autores que apuntan una aparente preferencia de los Titanosauriformes por los medios terrestres

Ichnological evidence of Megalosaurid Dinosaurs crossing Middle Jurassic tidal flats

A new dinosaur tracksite in the Vale de Meios quarry (Serra de Aire Formation, Bathonian, Portugal) preserves more than 700 theropod tracks. They are organized in at least 80 unidirectional trackways arranged in a bimodal orientation pattern (W/NW and E/SE). Quantitative and qualitative comparisons reveal that the large tridactyl, elongated and asymmetric tracks resemble the typical Late JurassicEarly Cretaceous Megalosauripus ichnogenus in all morphometric parameters. Few of the numerous tracks are preserved as elite tracks while the rest are preserved as different gradients of modified true tracks according to water content, erosive factors, radial fractures and internal overtrack formations. Taphonomical determinations are consistent with paleoenvironmental observations that indicate an inter-tidal flat located at the margin of a coastal barrier. The Megalosauripus tracks represent the oldest occurrence of this ichnotaxon and are attributed to large megalosaurid dinosaurs. Their occurrence in Vale de Meios tidal flat represents the unique paleoethological evidence of megalosaurids moving towards the lagoon, most likley during the low tide periods with feeding purposes

Las icnitas del Museo Numantino de Soria y su importancia para el patrimonio paleontológico.

Entre los materiales de la colección del Museo Numantino de Soria destaca una gran cantidad de especímenes con icnitas procedentes de la Comarca de Tierras Altas (Norte de la provincia de Soria). Todas ellas fueron recogidas en afloramientos de la Fm. Huérteles de edad Berriasiense. La colección conserva icnitas de dinosaurios, pterosaurios, cocodrilomorfos y tortugas. Si sumamos el número de holotipos que presenta, así como la cantidad de icnitas que preservan gran cantidad de detalles anatómicos y el hecho de que existan pocos lugares a nivel mundial con de yacimientos con icnitas de dicha edad hacen que dicha colección sea única y suponga un lugar de gran interés científico y patrimonial. Within the material of the collection of the Museo Numantino de Soria stand out the great amount of specimens with footprints. All of them come from the Tierra Altas region (North of Soria province). The footprints were recovered in the outcrops of the Hue´rteles Formation, that is Berriasian in age. The collection preserves tracks from dinosaurs, pterosaurs, crocodilomorphs and turtles. The number of holotypes, as well as the quantity of footprints preserving anatomical details, and the fact that there are few places in the world with Berriasian tracksites, makes the collection unique. Thus, it is a significant place both scientifically and patrimonally

Icnitas de dinosaurios saurópodos en la Formación Rayoso (Cuenca Neuquina, Albiense, Argentina)

Se describen por primera vez icnitas de dinosaurios saurópodos en la Formación Rayoso (Albiense) en Neuquén (Argentina). En dos afloramientos distintos del Miembro Rincón se han encontrado dos rastros de saurópodos con el paso estrecho. Uno de los rastros está formado por icnitas de pequeño tamaño, que podrían ser de un individuo juvenil. Otra posibilidad sería que los dos rastros sean de dos productores distintos. Los fósiles de dinosaurios son raros en la Formación Rayoso, evidencia posiblemente relacionada con su ambiente de depósito de gran aridez. Los diplodocoideos rebaquisáuridos son uno de los saurópodos más abundantes al final del Cretácico Inferior de la Cuenca Neuquina, de hecho los únicos dinosaurios conocidos en la Formación Rayoso pertenecen a esta familia. Se propone de manera tentativa que los rastros estudiados los produjeron diplodocoideos rebaquisáuridos, teniendo en cuenta el registro conocido y que los rastros de paso estrecho se asocian con diplodocoideos. Sauropod dinosaur tracks from the Rayoso Formation (Albian) in Neuquén (Argentina) are described for the first time. Evidence of two narrow-gauge sauropod trackways has been found in two distinct outcrops of the Rincón Member. One of the trackways consists of small-sized tracks and might belong to a juvenile individual. Another possibility is that the two trackways were produced by different species of sauropod. Dinosaur fossils are rare in the Rayoso Formation, possibly as a result of its arid depositional environment. Rebbachisaurid diplodocoids are one of the most abundant sauropods at the end of the Lower Cretaceous of the Neuquén Basin. Indeed, the only dinosaurs known from the Rayoso Formation belong to this family. Bearing in mind this exclusive presence and the association of narrow-gauge trackways with diplodocoids, it is tentatively proposed that the trackways under study were produced by rebbachisaurid diplodocoids

A new vertebrate assemblage from the matute formation of the Cameros Basin (Ágreda, Spain): implications for the diversity during the jurassic/cretaceous boundary

Altres ajuts: Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature.The Ribota site (Ágreda, Soria, Spain) is a new locality in the Matute Formation (Tithonian-Berriasian) composed of several carbonate layers, outstandingly rich in macrovertebrate remains. Fossils show an unusual replacement of the original bioapatite by quartz, and are found as positive reliefs protruding from lacustrine limestone beds. This type of conservation has allowed the identification of around one hundred vertebrate bone accumulations in an outcrop of more than 10 hectares. Osteichthyans (articulated partial skeletons, cranial material, and isolated postcranial bones and scales), crocodylomorphs (disarticulated cranial material, isolated teeth, vertebrae and osteoderms), turtles (partial carapaces and plastra, but also isolated plates) and pterosaurs (cranial and appendicular elements) have been identified. Around 80 specimens have been collected and a preliminary study of part of the collection (35 specimens) has allowed the identification of at least 5 different taxa: Halecomorphi indet., Neoginglymodi indet., Goniopholididae indet., Testudinata indet., and Pterodactyloidea indet. This new site represents one of the few sites from this time interval preserved in a fully lacustrine environment, so these vertebrate assemblages are unique and composed of different animals that presumably lived around and within the lake. They are dominated by aquatic and amphibian vertebrates and was formed by attrition in this lacustrine environment, possibly far from the lake shoreline. These macrovertebrate assemblages provide new data about the diversity in the faunal ecosystems from the Jurassic/Cretaceous transition of the Iberian Basin Rift System