27.9.16 0 comentarios

Morelladon y otros dinosaurios estiracosternos en las VII Jornadas de Salas de los Infantes


Uno de los grupos de dinosaurios más diverso y abundante durante el Cretácico Inferior, al menos en estos rincones de la Europa occidental, fueron también protagonistas en las VII Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno delebradas hace unos días en la localidad burgalesa de Salas de los Infantes. A través de una ponencia se abordó una puesta al día de la diversidad de ornitópodos estiracosternos (Iguanodon, Morelladon y Mantellisaurus) presentes en la Formación arcillas de Morella y hallados en la cantera del Mas de la Parreta

Aquí os dejamos un pequeño resumen:
Styracosterna is a monophyletic clade of medium to large bodied, quadrupedal, plant‐eating ornithopod dinosaurs that lived in both Gondwana and Laurasia and with a fossil record that extends throughout the Cretaceous. Most of the basal representatives of this clade, the nonhadrosauriform styracosternans, are known from different localities along the European continent. Currently seven genera and eight species of styracosternans are recognized from several Lower Cretaceous European formations [...]
[...] A recent re‐evaluation of the styracosternans of the Arcillas de Morella Formation at Morella locality indicates a higher diversity than historically known. Thus, the styracosternans species recognized are Iguanodon bernissartensis, Mantellisaurus atherfieldensis and the recently described Morelladon beltrani. Among this species, remains of Iguanodon bernissartensis are the most amply represented throughout different localities of the Formation. Remains of the other two styracosternans species are less abundant and restricted to single individuals. Finally, the species newly described, M. beltrani, provides a distinguishing component of the Arcillas de Morella Formation respect to its equivalent upper Wealden facies from northwest Europe Belgium and England), also characterized by the presence of Iguanodon bernissartensis and Mantellisaurus atherfieldensis.

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26.9.16 0 comentarios

Uso de técnicas analíticas para establecer protocolos de preparación paleontológica en las VII Jornadas de Salas de los Infantes


Y como no solo del estudio de los fósiles vive la paleontología, en las VII Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno celebradas en Salas de los Infantes (España) también se presentó usen trabajo acerca de la optimización de las labores de preparación de los propios fósiles. La comunicación, encabezada por Fátima Marcos, empleó metodologías alternativas, como la Tomografía Axial Computerizada (TAC), como herramienta para poder examinar y planificar la metodología idónea a seguir incluso antes de desembalar el bloque a preparar. 

El resumen de la comunicación es el siguiente: 

Since 2007, the various research projects developed on the biota of the site since its discovery indicate that in the Konzentrat‐Lagerstätten of Lo Hueco (Upper Cretaceous, Fuentes, Cuenca) are composed by a complex set of fossils representing a wide diversity of Late Cretaceous tetrapods, such as turtles, crocodilyforms and dinosaurs like ornithopods, basal neotheropods and dromaeosaurid, and sauropod titanosaurs (Ortega et al., 2015).
From the first moments of the field work, it was obvious the fragility of the vertebrate fossils surrounded and filled for a complicated matrix containing clays, gypsum and iron. This matrix made the fossils extremely sensitive to humidity changes, which can completely destroy some specimens (Collins et al., 1995). Many of fossils are affected by the growth of gypsum crystals, sometimes deforming or even destroying some of its parts. Also, a large number of the fossils are totally or partially covered by a layer of insoluble iron that, in many cases, prevents the access of the consolidation treatments and the direct visual inspection of fossils (Marcos‐Fernández & Ortega, 2016).
A first analysis of the conservational state of the paleontological collection was carried out with the aim of identifying deterioration agents that need to be controlled to reduce risks and to ensure the continued integrity of fossils over time (Waller, 2003). [...]
Using these analytical techniques has helped us to better understand the fossils, their risk agents, including minimization of these by small changes in the application of some preparation techniques.

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Nuevo titanosauriforme de Morella en las VII Jornadas de Salas de los Infantes


Durante las VII Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno de Salas de los Infantes (España) se presentó una nueva comunicación sobre dinosaurios saurópodos del Cretácico Inferior de Morella. Este trabajo liderado por Pedro Mocho (Grupo de Biología Evolutiva de la UNED) se centra en el estudio del material de saurópodos encontrado en el yacimiento de Sant Antoni de la Vespa (Morella). Su descripción ha posibilitado incorporar uno de los tres ejemplares encontrados en este yacimiento y concluir que corresponde a un miembro de Titanosauriformes, y más concrétamente a una forma cercana al sauropodo Tastavinsaurus sanzi.

Titanosauriformes are recorded from the Upper Jurassic to the uppermost part of the Upper Cretaceous. Several new specimens have been reported in the Barremian‐Aptian sediments of the Iberian Peninsula, particularly in the Maestrazgo Basin. These new discoveries are improving our knowledge about the evolutionary history of this group in the European territory during the Early Cretaceous. The site of Sant Antoni de la Vespa (Arcillas de Morella Formation, upper Barremian; Morella, Castellón) was discovered in 1998. In 2005 and 2008, two excavation campaigns were conducted. At least, remains of three sauropod individuals were collected. The most complete one comprises an articulated posterior cervical‐to‐anterior dorsal vertebrae sequence (probably five vertebrae), ribs, caudal vertebrae, chevrons, pelvis elements, one leg including an almost articulated and complete pes, and the other incomplete limb. Near this specimen, ribs, caudal vertebrae and hindlimb elements of, at least, two other smaller individuals were identified, including two almost complete legs. All comparable elements present a similar morphology suggesting that they probably correspond to members of the same taxon. A brief description of Sant Antoni de la Vespa sauropods is provided, mainly based on one of the smaller individuals. The Sant Antoni de la Vespa sauropod presents several features commonly found within Titanosauriformes, such as the presence of a pronounced lateral bulge in the femur and an anteroposteriorly compressed femoral shaft (the lateromedial diameter of the shaft is 185% than the anteroposterior one). This sauropod also shares with more derived titanosauriforms than brachiosaurids the following features: i) crest‐like anterior trochanter on the fibula; ii) well‐developed trochanteric shelf in the femur; iii) transversely expanded tibial distal end; and iv) the presence of a well‐marked linea intermuscularis cranialis (shared by derived titanosaurs, including saltasaurines; Otero, 2010). Some distinctive features observed in one of the smaller specimens can be explained due to ontogeny. The Barremian‐Aptian sauropod faunas of the Iberian Peninsula include the titanosauriform Tastavinsaurus sanzi and the rebbachisaurid Demandasaurus darwini. A preliminary phylogenetic analysis places Sant Antoni de la Vespa sauropod within Titanosauriformes, in a phylogenetic position closely related with Tastavinsaurus. However, Sant Antoni de la Vespa sauropod does not share any authapomorphy of T. sanzi (see the revised diagnosis of Tastavinsaurus in Royo‐Torres et al., 2012) and both taxa mainly differ in the morphology of the femur and pes. This suggests that the Sant Antoni de la Vespa sauropod represents a different titanosauriform taxon. According to this, the known palaeodiversity of titanosauriforms for the Iberian realm during the Early Cretaceous seems to be higher than expected.

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23.9.16 0 comentarios

La enigmática tortuga Kallokibotion en las VII Jornadas de Salas de Los Infantes


Kallokibotion es una tortuga primitiva europea, definida hace casi un siglo pero, hasta ahora, mal conocida debido a la mala preservación del material clásico, y a la ausencia de nuevos ejemplares hasta ahora disponibles en la literatura. En las VII Jornadas de Salas de Los Infantes se han presentado varios nuevos ejemplares, muy bien preservados, que permiten tener una nueva visión sobre esta relevante tortuga.

El resumen de esta comunicación es el siguiente:

The information on the European continental turtle faunas of the Upper Cretaceous is relatively good. Two main groups of freshwater turtles are identified in both Western Europe and Central-Eastern Europe: Dortokidae (stem Pleurodira) and Bothremydidae (Podocnemidoidea, Pleurodira) The so far known fauna of terrestrial turtles in the uppermost Cretaceous of both regions of the European archipelago is composed of different taxa: Solemydidae in Western Europe and the enigmatic Kallokibotion in the other part of the archipelago, identified in the Haţeg Basin (Transylvania, Romania). Nopcsa (1923a, 1923b) defined Kallokibotion from several specimens. Gaffney and Meylan (1992) reviewed the classic specimens, performing a new study of this taxon. However, they indicated that the relatively poor preservation and the scarce availability of characters in the known remains restricted their ability to determine the osteology of Kallokibotion. Very scarce material of this taxon has subsequently being presented, and has been hardly analyzed in depth.
Abundant and well-preserved new material attributable to Kallokibotion, from several locations of the Haţeg Basin, is presented here. Its study, and the detailed comparison with both the classic material of this taxon and with other stem testudines, allow us describing many hitherto unknown characters for Kallokibotion, providing a better anatomical characterization for this primitive turtle. These characters correspond to both cranial and postcranial elements. Some previous hypotheses about the anatomy of this taxon are confirmed, but others are refuted. The new information is incorporated in several phylogenetic analyses. Thus, new information about its phylogenetic position, now under discussion, is also provided.
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22.9.16 0 comentarios

Un nuevo ejemplar de un pequeño dinosaurio terópodo del Jurásico Superior de Portugal


Hace pocos días se publicó en la revista Historical Biology la descripción de un nuevo ejemplar de pequeño dinosaurio terópodo procedente del Jurásico Superior portugués. El ejemplar fue descubierto en el litoral del área central de la cuenca lusitánica por José Joaquim dos Santos, uno de los colaboradores de la Sociedade de História Natural de Torres Vedras, institución en la cual está depositado actualmente el ejemplar.

El material de estudio está constituido por un conjunto de vértebras cervicales, dorsales, sacras y caudales, costillas y elementos de la cintura pélvica. Es uno de los ejemplares de dinosaurios terópodos más completos y el unico individuo juvenil (no neonato) conocido hasta la fecha en el registro portugués.


Este ejemplar presenta una combinación de caracteres compartida con otras formas conocidas en el Jurásico Superior de Portugal como Allosaurus y Lourinhanosaurus, pero también diferencias con respecto a ambos taxones. Algunas de estas diferencias pueden estar relacionadas con la condición juvenil del ejemplar, pero otras características aparentemente no entran en el rango de la variabilidad conocida para estos taxones y podrían tener significado taxonómico. Debido a la presencia de tres formas estrechamente relacionadas y prácticamente sincrónicas, y a que no se conoce bien la variabilidad de estos taxones del Jurásico Superior portugués (especialmente Lourinhanosaurus), se ha optado por asignar el nuevo ejemplar como un alosauroideo indeterminado.

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21.9.16 0 comentarios

Los sauropterigios triásicos de Canales de Molina en las VII Jornadas de Salas de los Infantes


Seguimos con los trabajos presentados por miembros del Grupo de Biología Evolutiva de la UNED en las VII Jornadas Internacionales de Dinosaurios y su Entorno celebradas en la localidad burgalesa de Salas de los Infantes. Hoy es el turno de un trabajo presentado por Carlos de Miguel Chaves, que hizo una puesta al día de los restos de sauropterigios del Triásico Medio encontrados en las cercanías de la localidad de Canales de Molina (Guadalajara).

Estos fueron encontrados y notificados a principios de los años 80, pero a día de hoy permanecen sin figurar ni describir en detalle. Entre los restos estudiados se identifican fósiles pertenecientes a diferentes tipos de placodontos y eosauropterigios.

The sauropterygian remains from Canales de Molina include teeth, isolated vertebrae, ribs, appendicular elements and osteoderms of several clades. As noted by Alférez et al. (1983), several elements belong to non-cyamodontoid placodonts and nothosaurids, and some of the nothosaur remains could belong to the genus Nothosaurus. However, Alférez et al. (1983) did not mention the presence of cyamodontoids, represented by teeth, isolated osteoderms and carapace fragments. Thus, the study of all these elements allows the identification of indeterminate cyamodontoid and non-cyamodontoid placodonts, indeterminate eosauropterygians, and nothosaurids. Therefore, the record of Sauropterygia from the Muschelkalk of Canales de Molina is consistent with those from other fossil sites of the Iberian Peninsula, and its detailed study provides new information about the taxonomy, systematic and diversity of the Iberian representatives of the Triassic sauropterygians. 

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Reevaluación de ejemplares asignados al cocodrilo Allodaposuchus precedens en las VII Jornadas de Salas de los Infantes


En otra de las comunicaciones presentadas en las VII Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno de Salas de los Infantes (Burgos), se llevaba a cabo una reevaluación de diferentes ejemplares fragmentarios de crocodilomorfos que tradicionalmente se han relacionado con el eusuquio basal Allodaposuchus precedens. Este taxón se describió en 1928 a partir de material craneal y postcraneal procedente del Maastrichtiense inferior (Cretácico Superior) de Rumania. El estudio detallado de nuevas formas de eusuquios basales que han ido apareciendo en los últimos veinte años en localidades campano-maastrichtienses de la Península Ibérica, Sur de Francia y Rumania ha permitido recientemente la definición de un nuevo clado denominado Allodaposuchidae. Por tanto, la revisión de toda esta colección de restos fragmentarios era necesaria teniendo en cuenta el nuevo paradigma del grupo. A continuación dejamos un resumen de la comunicación:

During the last two decades, several specimens of eusuchian crocodyliformes have been described from the Campanian and Maastrichtian (Late Cretaceous) record of Europe. Most of them are included in the recently described clade Allodaposuchidae. This clade has been placed, in the last phylogenetic hypotheses, as sister group of Hylaeochampsidae and forming with these a basal group of Eusuchia, or as the sister group of Crocodylia. The type species of Allodaposuchidae is Allodaposuchus precedens, described from fragmentary cranial and postcranial remains found in lower Maastrichtian levels of Vălioara (Romania). The group also comprises the species described in Spain Arenysuchus gascabadiolorum, Lohuecosuchus megadontos, Agaresuchus subjuniperus, Agaresuchus fontisensis and Musturzabalsuchus buffetauti, and the species from southern France Lohuecosuchus mechinorum, in addition to the problematic forms “Allodaposuchus palustris” and “Allodaposuchus hulki”, from Spain, and “Massaliasuchus affuvelensis”, from France.
Several specimens from Spain, southern France and Romania were assigned to Allodaposuchus precedens by different authors. The remains from Velaux-La Bastide Neuve probably represent an ontogenetic series of an allodaposuchid. A thorough review of these remains is necessary in order to clarify their phylogenetic status according the new paradigm within the group, with the restriction of Allodaposuchus precedens to some Romanian specimens. The cranial material from Armuña was included in the re-evaluation of Allodaposuchus precedens, while the mandibular remains of this site were assigned to Musturzabalsuchus buffetauti. This material has recently been proposed as belonging to a single taxon, currently under study, but its placement within Allodaposuchidae is still unknown. Due to its fragmentary nature, the remains from Vilamitjana, Laño, Cruzy and Bellevue probably do not provide characters that allow a precise systematic assignment, but the synapomorphies of the clade Allodaposuchidae can be recognized in all of these specimens. Thus, the detailed study of the material presented here provides a reevaluation of the taxonomic assignment of each of these remains. 
The result of this study support the hypothesis proposing a vicariant distribution pattern between the forms distributed in western Europe and those from central-eastern Europe during the uppermost Cretaceous.

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20.9.16 0 comentarios

Vertebrados de la Cuenca de Tremp en las VII Jornadas de Salas de los Infantes


Como ya se ha comentado, los días 8 y 9 de septiembre se celebró en Salas de los Infantes la séptima edición de las Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno, motivo por el cual la mayor parte del equipo del Grupo de Biología Evolutiva de la UNED se desplazó hasta la localidad burgalesa. Uno de los trabajos que se presentaron en forma de póster fue una revisión de parte de los fósiles de vertebrados recuperados en los años 50 por Emiliano Aguirre y Albert de Lapparent en la Cuenca de Tremp, y que fueron depositados en el MNCN de Madrid. A continuación el resumen del póster:

Although the paleontology of Mesozoic vertebrates was a discipline which experienced an important development during the second half of the 19th century and the first half of the 20th in several European countries (e.g. Great Britain, Germany or France), these studies barely had relevance in Spain during that period. Among the first notified discoveries of Spanish Mesozoic vertebrate remains highlighting those of dinosaur bones reported by Justo Egozcue and by Juan Vilanova y Piera, at the second half of XIX century (Vilanova y Piera, 1872, 1873; Egozcue, 1873). José Royo y Gómez was the first Spanish researcher who pursue several objectives focused on the discovery and systematic study of Spanish Mesozoic reptiles, most of them from Morella (Castellón) and Benagéber (Valencia). He published several results in various papers, over nearly a decade, between 1918 and 1927 (see Pérez García et al., 2009 and references there). However, the Spanish Civil War interrupted the career of Royo y Gómez in Spain, this discipline being paralyzed during the post-war period. The next relevant paleontological activities related to the Mesozoic sites with vertebrates were those performed in the Tremp Basin (Catalonia). In fact, these findings and activities can be considered as some of the most important from a historical perspective, since they are part of the origins of the modern Spanish vertebrate paleontology, and also the first collaborations between Spanish and foreign palaeontologists specialists in the study of Mesozoic vertebrates. Although some occasional discoveries at this Catalonian region occurred at the first quarter of the 20th century, close to the Sant Antoni dam, the first paleontological surveys and excavations in the region were not performed until the 1950s. In 1955, the “Instituto Lucas Mallada” (current Department of Geology of the “Museo Nacional de Ciencias Naturales”, in Madrid) sponsored an expedition in the area, which was attended by Emiliano Aguirre along with other national and European researchers, as is the case of the French paleontologist Albert de Lapparent. New sites were discovered and several Mesozoic vertebrate remains were recovered in 1955, but also in 1956 (Pereda-Suberbiola & Ruiz-Omeñaca, 2012). Thus, Lapparent and Aguirre (1956a, b) recognized the presence of the sauropod dinosaurs Hypselosaurus and Titanosaurus, the ornithopod Rhabdodon priscum, and also indeterminate crocodiles and turtles. All these sites in the Tremp Basin are now recognized as located in Maastrichtian levels, corresponding to the lower part of the Tremp Formation (Riera et al., 2009; Rosell et al., 2001).

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Hoy nos visita... Aitziber Suárez



Durante la semana pasada, el Grupo de Biología Evolutiva de la UNED recibió la visita de Aitziber Suárez Bilbao, del País Vasco. Aitziber es una estudiante de doctorado de la Universidad del País Vasco (UPV/EHU) que está realizando su tesis sobre las faunas de vertebrados del Pleistoceno del yacimiento de Artazu VII (Arrasate, Gipuzkoa). Durante su visita estuvo con varios miembros del GBE poniendo en práctica varias técnicas con algunos de sus restos. 
19.9.16 0 comentarios

Los saurópodos de Morella del MNCN en las VII Jornadas de Salas de los Infantes


En las recientes VII Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno celebradas en Salas de los Infantes (España) se presentó una comunicación enfocada en el material de dinosaurios saurópodos de las colecciones del Museo Nacional de Ciencias Naturales en Madrid. Este material clásico encontrado en la segunda mitad del siglo XIX se ha revisado en detalle en un trabajo liderado por Pedro Mocho (Grupo de Biología Evolutiva de la UNED). El estudio del material ha permitido identificar formas afines al grupo Titanosauriformes, y sugiere la presencia de al menos formas distintas registradas en los sedimentos de la Formación Arcillas de Morella (Barremiense Superior).

Barremian‐Aptian sauropod faunas of the Iberian Peninsula include two described taxa, the titanosauriform Tastavinsaurus sanzi and the rebbachisaurid Demandasaurus darwini. In addition, recently found and historical specimens have been referred, especially in the Spanish areas of Morella (Castellón, Comunidad Valenciana) and Burgos (Castilla y León) (e.g. Canudo et al., 2008; Torcida Fernández‐Baldor et al., 2011, 2013; Royo‐Torres et al., 2012). The sediments of the Arcillas de Morella Formation are known, since the second half of the 19th century, by their relatively abundant fossil record of Lower Cretaceous vertebrates, especially in the Morella region. Several classic specimens of fossil reptiles, so far unpublished or not studied in detail, are housed in the Museo Nacional de Ciencias Naturales (MNCN), in Madrid (Spain). In fact, most of the first remains of dinosaurs discovered in Spain are part of the collection of vertebrate palaeontology of that institution. Juan Vilanova y Piera (1872; 1873) notified the finding of fragmentary remains of dinosaurs in Morella. Although he attributed these specimens to the ornithopod dinosaur Iguanodon, one of the currently preserved specimens at MNCN collections belong to a sauropod (Ruiz‐Omeñaca & Pereda‐Suberbiola, 1999; Ruiz‐Omeñaca et al., 2003). José Royo y Gómez was the first Spanish paleontologist who systematically collected dinosaur remains, and also performed the first systematic approaches based on comparative studies with specimens deposited in other European countries. However, the Spanish Civil War marked the end of these researches (see Pérez‐García et al., 2009). Most of the fossil remains collected by Royo y Gómez come from Morella. Herein, the sauropod historical material collected in Morella and housed in MNCN is described and discussed. Most of the elements were found isolated. These remains include a set of axial (dorsal and anterior and posterior caudal vertebrae) and appendicular elements (few appendicular bones, including two humeri, a femur, and pes and manus elements). The morphology presented by the caudal vertebrae is compatible with those of Titanosauriformes, sharing the presence of a significantly anteriorly displaced neural arch, and a dorsoventrally compressed centrum in the anterior caudal and some of the posterior caudal vertebrae. Two humeri morphotypes are recognized. The systematic study of this collection allows us to recognize two sauropod taxa (at least, one titanosauriform) in the sediments of the Barremian Arcillas de Morella Formation outcropping in the Morella area. None of them seems to represent a rebbachisaurid.

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