27.7.18 0 comentarios

Tortugas de Niger en el XVI Annual Meeting de la EAVP


Y dando un paso más allá en el espacio (esta vez pasando a Laurasia y, más específicamente, a Níger) y en el tiempo (ahora tocan tortugas del Cretácico Inferior), el último trabajo sobre tortugas fósiles que fue presentado por miembros del Grupo de Biología Evolutiva de la UNED en el XVI encuentro anual de la EAVP trata sobre la tortuga de Gadoufaoua Taquetochelys.

El resumen es el siguiente:

The most abundant and diverse collection of Pleurodira from the Lower Cretaceous record of Africa comes from the Aptian levels of Gadoufaoua. Gadoufaoua is located in the Illumeden Basin of the Ténéré Desert, in central Niger. The first African araripemydid, Taquetochelys decorata, was defined based on several remains from this locality. It is the first described araripemydid is the Brasilian Aptian-Albian Araripemys barretoi. Therefore, the finding of this lineage of freshwater forms in Africa was relevant, because it represents a group of freshwater turtles distributed in both South America and Africa during the Early Cretaceous.
The type series of Taquetochelys decorata was composed of several isolated plates. The identifi-cation of other specimens attributable to the same form was notified. However, they remained as unpublished. Considering the limited information available, subsequent authors indicated that the attribution of this African form to Araripemydidae should be confirmed by the finding of more complete remains. Fortunately, one of the most complete Lower Cretaceous skeletons of Pleurodira was recently identified in Gadoufaoua. This specimen corresponds to an unquestionable member of Araripemydidae. However, it was attributed to a new taxon, Lagaremys tenerensis.
The type series of Taquetochelys decorata is here revised, and other unpublished specimens are studied. The detailed comparison between Lagaremys tenerensis and Taquetochelys decorata is carried out. For this purpose, the intraspecific variability of several pleurodires, including the ara-ripemydid Araripemys barretoi, is analyzed. Considering all this information, the hypothesis about the identification of Taquetochelys decorata and Lagaremys tenerensis as two different forms is evaluated.

Esta presentación está relacionada con una publicación que ha sido recientemente publicada, y que fue comentada aquí.

26.7.18 0 comentarios

Patologías en vértebras de titanosaurios de Lo Hueco en el XVI Annual Meeting de la EAVP


Los dinosaurios también padecían enfermedades y sufrían heridas. Sin embargo, la única evidencia directa que se tiene en vertebrados fósiles son las alteraciones óseas ya que los tejidos blandos no se conservan. Este es el tema de otro de los trabajos presentados durante el XVI Annual Meeting de la European Association of Vertebrate Paleontologists (EAVP), sobre diversos tipos de patologías identificadas en diversas series caudales de dinosaurios titanosaurios del yacimiento del Cretácico Superior de Lo Hueco (Fuentes, Cuenca).

Como resultado se presentaron 10 vértebras caudales y 4 arcos hemales con patologías de origen traumático, congénito-traumático y degenerativo–idiopático manifestando bien el crecimiento de masa ósea o bien su pérdida y evidenciados por discontinuidades, destrucción ósea, aumento y alteraciones de densidad. Aquí va el resumen:

The paleontological site of Lo Hueco (Upper Cretaceous, Spain, Cuenca) has provided a great variety of partial skeletons of articulated titanosaurs, providing a unique paleontological record in Europe. In the present study, some titanosaur series of caudal vertebrae from the site were revised for the first time in order to determine possible pathologies affecting these individuals.

A comparative anatomical study was carried out to determine the diversity of morphologies present in the titanosaurs of Lo Hueco and to discriminate possible pathological conditions from intraspecific variability, and diagenetic or biostratinomic deformation.

Subsequently, 14 pathological elements have been identified, 10 corresponding to caudal vertebrae and 4 belonging to haemal arches. Differential diagnosis has been carried out on all of the specimens based on a macroscopic analysis occasionally supplemented with computerized tomography (CT) scan explorations.

As results, spondylosis deformans has been identified in two vertebral centra, two cases of subchondral cysts, three fissured haemal arches, a dislocation of the chevron in a vertebral centrum, several elements affected by enthesophytes, and a vertebra with a modified prezigapophysis and outline of the anterior articular face of congenital or traumatic origin.

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25.7.18 0 comentarios

Puesta al día sobre el registro de Pleurodira británico en el XVI Annual Meeting de la EAVP


Además de tortugas ibéricas, el Grupo de Biología Evolutiva de la UNED también defendió en el XVI encuentro anual de la EAVP un par de trabajos sobre tortugas de otros países. El primero de ellos correspondía al registro de Bothremydidae del Eoceno de Gran Bretaña.

El resumen es el siguiente:

The British record of Pleurodira is very limited, contrasting with that of Cryptodira. It is restricted to a few poorly known and poorly represented taxa from the lower Eocene record. Two successful lineages of Pleurodira are identified in the Eocene levels of Europe: Bothremydidae and Podocnemididae. Both clades have been identified in the lower Eocene British record.
A single specimen attributable to Podocnemididae is recognized in the British record, through a partial shell, from Bracklesham Bay (Sussex). It was attributed to the recently described littoral genus Eocenochelus. Several almost complete or partial shells of coastal bothremydid turtles have been found, since the 19th century, in the London Clay of the Isle of Sheppey. Four different species were defined in the 19th century but subsequent authors indicated that all of them could represent a single form. No detailed review of these specimens has been made after the 1950s, and no photographs of any of these classic specimens had been, until now, published. The detailed study of those classic specimens is performed, and photographs and schematic drawings of all of them (except for the missing holotype) are presented here for the first time. In addition, several shells subsequently found, are also analyzed to improve the knowledge about both the shell anatomy and variability of this potential single species. Thus, the diversity of Bothremydidae in the British record is evaluated, as well as the precise systematic position of the recognized form or forms.

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24.7.18 0 comentarios

Paleodiversidad de crocodilomorfos en el XVI Annual Meeting de la EAVP


En el primer simposio europeo acerca de la evolución de los crocodilomorfos, celebrado en el XVI encuentro anual de la EAVP, A. de Celis presentó una comunicación oral del trabajo titulado “Revisiting the biodiversity curve of modern crocodiles (Crocodyliformes, Eusuchia)”. En este trabajo, realizado en colaboración con I. Narváez y F. Ortega del Grupo de Biología Evolutiva de la UNED, se presentaron nuevas curvas de paleodiversidad estimadas a partir del registro fósil de los cocodrilos eusuquios. Estos resultados se mostraron también divididos según continentes y según grandes linajes de Crocodylia (Alligatoroidea, Crocodyloidea y Gavialoidea), permitiendo por tanto entender cómo ha variado la diversidad de los cocodrilos eusuquios en términos espaciales, temporales y filogenéticos. Aquí el resumen:

The fossil record of modern crocodiles (Eusuchia) shows that, although their diversity is currently restricted to 23 recognized species circumscribed in three major lineages, in the past they were more abundant and had a wider distribution. Historically, many fragmentary fossils with limited diagnostic characters have been assigned to certain species exclusively on the basis of a shared spatiotemporal distribution. The large amount of these improperly justified taxonomic assignments should be taken into account in order to reconstruct the paleodiversity of any clade, as these occurrences could introduce another bias.

Regarding this issue, an exhaustive review of more than one thousand eusuchian body fossil occurrences at specific level has been carried out in order to build a new dataset, excluding dubious fossil occurrences. Following previous works, these occurrences were sorted into time-bins of about 9 million years and shareholder quorum subsampling (SQS) was applied to the dataset, obtaining a subsampled biodiversity curve comprising the entire timespan of Eusuchia. The resulting curve shows two great increases in eusuchian biodiversity, the first one during the Paleocene and the second one during the Middle-Late Miocene. These results are quite consistent with proposals already known. However, in contrast with previous works, our results suggest that the Middle-Late Miocene biodiverstity peak was bigger than that of the Paleocene. The Middle-Late Miocene biodiversity peak is related to the great expansion of alligatoroids in South America, with minor contributions of the gavialoid expansion in South America alongside the crocodyloid expansion in Africa and Australasia.

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23.7.18 0 comentarios

El placodonto Parahenodus atancensis en el XVI Annual Meeting de la EAVP


Ya estáis viendo estos días lo mucho que ha dado de sí para el GBE el último Encuentro de la EAVP, celebrado en Caparica (Portugal). Hoy le toca el turno al recientemente descrito placodonto Parahenodus atancensis, cuyo estudio fue presentado en formato póster en el congreso. 

Sin más dilación, aquí va el abstract:

Henodus chelyops, from the Carnian (Upper Triassic) of Tübingen (Germany), is a highly derived cyamodontoid placodont, showing an extremely modified skull compared with other representatives of Cyamodontoidea. Based on this, trophic adaptations very different from those of other placodonts have been proposed. Whereas the other taxa are durophagous animals, herbivory and filter feeding has been suggested for H. chelyops. The phylogenetic position of this taxon within Cyamodontoidea could not be, until now, well established.

We present a partial skull of a cyamodontoid recently found in El Atance fossil site (Upper Triassic, Guadalajara, Spain), MUPA-ATZ0104. MUPA-ATZ0104 corresponds to a new taxon. Its inclusion in a cladistic analysis shows it is the sister taxon of H. chelyops. Both taxa are identified as members of the clade Henodontidae, hitherto considered as monotypic. Several character states previously recognized as exclusive of H. chelyops are synapomorphies of Henodontidae, including: maxillae without teeth; a single palatine tooth; upper temporal fenestrae reduced to absent; broad parietals; palatines separated by pterygoids. Based on this information, the diagnosis of Henodontidae is emended. This clade is recognized as belonging to Cyamodontida.

In addition to the presence of several character states hitherto considered as autapomorphies of H. chelyops, MUPA-ATZ0104 shares other character states with some less derived cyamodontoid placodonts, including: skull narrowed anteriorly; upper temporal fossae opened; larger palatine teeth. The discovery of this new form provides important information on both the acquisition of the highly specialized cranial morphology of H. chelyops and the evolutionary history of the clade Henodontidae. 
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20.7.18 0 comentarios

Los cocodrilos del yacimiento cenomaniense de Algora en el XVI Annual Meeting de la EAVP


Entre los trabajos presentados por los integrantes del Grupo de Biología Evolutiva de la UNED en el reciente XVI Annual Meeting de la European Association of Vertebrate Paleontologists (EAVP), se encuentra esta comunicación acerca de los nuevos avances en el estudio de la fauna de crocodiliformes del Cenomaniense de Algora (alrededor de hace 90 millones de años). Los nuevos descubrimientos que han tenido lugar durante las últimas campañas, permiten hacernos una idea de la variabilidad de cocodrilos en este yacimiento de la provincia de Guadalajara, de gran importancia para conocer la transición de faunas entre el Cretácico Inferior y la parte terminal del Cretácico Superior. El resumen del trabajo es el siguiente:

The information regarding the crocodyliform faunas from the Lower and the uppermost Cretaceous of Europe is relatively abundant. Different clades integrated the continental faunas of crocodyliforms in both periods. Lower Cretaceous faunas were mainly composed by non-eusuchian members of Neosuchia, whereas the uppermost Cretaceous faunas were represented by non-crocodylian representatives of Eusuchia. The information relative to the European crocodyliforms present during the lower part of the Upper Cretaceous is remarkably limited. Therefore, the discovery of new material assignable to Crocodyliformes is essential in order to shed light on this faunal turnover.

In this context, the Spanish uppermost middle-lowermost upper Cenomanian site of Algora (Guadalajara, Central Spain) provides relevant information regarding this issue. This site has yielded numerous material assigned to Crocodyliformes, especially as a result of the latest fieldworks. These new remains comprise well-preserved and complete isolated cranial (e.g., ectopterygoid, exoccipital) and postcranial (e.g., rib, vertebrae) remains, including a dorsal vertebra, attributable to a member of Eusuchia. The detailed analysis of the crocodyliforms remains from Algora allows increasing the knowledge on the faunal association from this relevant Cenomanian fossil site.

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19.7.18 0 comentarios

Nueva publicación sobre las pleurodiras africanas: la tortuga del Paleoceno de Angola Taphrosphys congolensis


Taphrosphyina es un grupo de tortugas pleurodiras (Bothremydidae) que sobrevivió a la crisis de extinción masiva del final del Cretácico, siendo conocido entre el Cretácico Superior y el Eoceno. Este exitoso grupo habitaba en varios continentes: Norteamérica, Sudamérica, Europa, África y Asia. Clásicamente, la mayoría de sus representantes se atribuían al género Taphrosphys. Sin embargo, los estudios realizados en la última década han permitido reconocer una amplia diversidad. Así, varias de las atribuciones clásicas a Taphrosphys han sido refutadas o puestas en duda.

Taphrosphys congolensis es una tortuga del Paleoceno de Angola. Escasos elementos del caparazón de esta especie habían sido, hasta ahora, publicados. Numerosos restos hallados hace casi un siglo, pero hasta ahora inéditos, son descritos y figurados en un nuevo artículo que acaba de ser publicado en la revista Historical Biology. Este estudio permite caracterizar varias regiones del caparazón de esta forma que eran, hasta ahora, desconocidas. Además, se reconoce variabilidad para varios caracteres, permitiendo una detallada caracterización de su caparazón.

Únicamente otra especie conocida por el caparazón es confirmada como un miembro del género Taphrosphys: la especie del Paleoceno de Norte América Taphrosphys sulcatus. A pesar del escaso conocimiento hasta ahora disponible sobre el caparazón de Taphrosphys congolensis, varios investigadores previos habían establecido supuestas diferencias entre esta especie africana y la norteamericana. El mejor conocimiento sobre el caparazón de Taphrosphys congolensis permite refutar la mayoría de ellas, caracterizando el caparazón de este género como muy estable. Como consecuencia, se refuta la atribución de otras formas al género Taphrosphys, como es el caso de la especie del Cretácico de Francia ‘Tretosternumambiguum, o la del Eoceno de Perú ‘Podocnemisolssoni. Así, el registro de Taphrosphys queda restringido del Cretácico Superior-Eoceno, a únicamente el Paleoceno.


Resumen del nuevo trabajo es el siguiente:

The bothremydid pleurodiran turtle Taphrosphys congolensis is a member of Taphrosphyina from the Paleocene of the Cabinda Province (Congo Basin, Angola). Very few specimens corresponding to elements of its shell have been so far figured. Abundant unpublished remains are analyzed in this paper. As a consequence, several regions of the shell are figured and characterized here for the first time, and intraspecific variability is recognized for several characters. Previous authors proposed some putative differences between the shells of Taphrosphys congolensis and the North American Paleocene Taphrosphys sulcatus. The increase in the knowledge about the shell of this African form allows us to refute most of them, the shell of both forms being recognized as more similar than previously identified. Thus, the identification of the genus Taphrosphys as restricted to three forms (i.e. the skull taxon Taphrosphys ippolitoi, and the skull and shell forms T. congolensis and T. sulcatus) is supported, and the record unquestionably attributable to this genus is modified from the Upper Cretaceous–Eocene lapse of time to the Paleocene exclusively.


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18.7.18 0 comentarios

Iguanodon bernissartensis en el XVI Annual Meeting de la EAVP


Siguiendo con las aportaciones sobre ornitópodos en el XVI Annual Meeting de la European Association of Vertebrate Paleontologist (EAVP), la Comarca de Els Ports también tuvo su sesión con la presentación de una serie de nuevos restos craneales del yacimiento CMP-11 de la Cantera del Mas de la Parreta pertenecientes, al menos, a dos individuos de ornitópodos estiracosternos.

A pesar de que previamente ya se conocía la presencia de estos dos nuevos individuos en este yacimiento, los nuevos datos aportados en este congreso confirman de manera inequívoca al archiconocido estiracosterno Iguanodon bernissartensis como el ornitópodo presente en CMP-11.

Aquí va el resumen:

The Barremian Arcillas de Morella Formation (Eastern Spain) has yielded a high diversity of vertebrates. The most representative fossil site of this formation is the Mas de la Parreta quarry (CMP), located at the southwest of the locality of Morella (Castellón province, Spain). The best represented dinosaur group are styracosternan ornithopods that are by far the most abundant dinosaurs throughout the Iberian Lower Cretaceous. To date, three styracosternan species have been recognized: Iguanodon bernissartensis, Mantellisaurus atherfieldensis and Morelladon beltrani. Several individuals of I. bernissartensis have been recovered in di erent sites of CMP being the most common styracosternan in the formation.
CMP-11 is one of the sites inside the CMP in which cranial and postcranial bones of
I. bernissartensis have been discovered. Previously, two isolated maxillae have been reported from this site providing new information about the skull anatomy of I. bernissartensis. Here, new cranial bones have been examined for the first time. These bones correspond to the rostral portion of both sutured premaxillae, a second incomplete right premaxilla, a nearly complete dentary, two quadrates and several isolated dentary and maxillary teeth. The presence of two right premaxillae indicates the presence of at least two individuals. These cranial bones can be confidently referred to Iguanodon bernissartensis based on a unique combination of shared characters, as an autapomorphic extensive vertical buttress of the quadrate. This new material corroborates the abundant presence of a form compatible with I. bernissartensis in the Iberian Peninsula that would constitute the southern limit of its current distribution.

17.7.18 0 comentarios

La placa colgante de Balmorí en el Congreso de Paleoambiente y Recursos bióticos del Pleistoceno Superior Cantábrico


Entre el 27 y 29 de junio se celebró en Bilbao un congreso como homenaje a los investigadores Pedro Castaños y Carmen Sesé que versó sobre Paleoambiente y Recursos Bióticos del Pleistoceno Superior Cantábrico (PRB2018 Bilbao).

En una de las comunicaciones realizadas se discutió la naturaleza del soporte de la placa colgante con grabado de la Cueva de Balmori (Asturias), tradicionalmente identificada como una placa de tortuga.

Esta comunicación es un adelanto de un trabajo en preparación que se espera publicar en un volumen especial sobre el congreso en la revista KOBIE.

El resumen de la comunicación es el siguiente:

La cueva de Balmori (Asturias) se localiza a unos 600 m. del pueblo que le da nombre y a 500 m. del estuario del río Barro. El yacimiento arqueológico fue descubierto en 1908 por Alcalde del Río y fue excavado y estudiado en décadas posteriores. En la entrada de la cueva se encuentra un complejo culturalmente adscrito al Paleolítico Superior con ocupaciones del Solutrense, Magdaleniense, Aziliense y Asturiense, si bien en algunas zonas interiores de la cueva se hallaron útiles del Paleolítico Inferior. Vega del Sella (1930) publicó la presencia de una placa ósea con perforaciones y un grabado de bovino, recuperada en contexto del Magdaleniense final e inicios del Aziliense. En la descripción de la pieza, al tratarse de un hueso plano, indicó que el soporte podría ser un trozo de caparazón de una gran tortuga, siendo en tal caso la primera vez que se encontraban restos de este animal en el arte mobiliar. Más tarde, Barandiarán (1972) puso en duda la sugerencia de Vega del Sella sobre el soporte, realizando una descripción y análisis general de los grabados, pero indicando no poder afirmar si la pieza se trataba de una falsificación reciente, planteando dudas sobre su cronología paleolítica. Corchón (1986) en su descripción de la pieza y de los motivos grabados en ella, también dudó de la sugerencia de Vega del Sella.
El objetivo que se persigue en este trabajo es el de discutir la naturaleza de esta placa ósea. La posible identificación como una falsificación es actualmente refutada.

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  • Referencia: I. Boneta; A. Pérez-García; C. Liesau. 2018. Sobre la naturaleza del soporte de la placa ósea colgante de La Cueva de Balmori (Asturias). Libro de resúmenes del Congreso de Paleoambiente y Recursos bióticos del Pleistoceno Superior Cantábrico: estado de la cuestión a la luz de las nuevas investigaciones.
16.7.18 0 comentarios

Los cocodrilos alodaposúquidos del Cretácico Superior de Rumanía en el XVI Annual Meeting de la EAVP


Otro de los trabajos presentados por integrantes del Grupo de Biología Evolutiva de la UNED en el pasado XVI Annual Meeting de la European Association of Vertebrate Paleontologists (EAVP) fue la comunicación sobre el estudio sistemático de algunos ejemplares de alodaposúquidos procedentes del Maastrichtiense de Rumanía. Allodaposuchidae es un clado de crocodiliformes recientemente descrito y está integrado por formas exclusivamente europeas restringidas al Cretácico Superior. En el presente trabajo se analiza la validez de la especie Allodaposuchus precedens y la designación de un neotipo de la misma. El resumen es el siguiente:

Allodaposuchus precedens is a basal member of Eusuchia, established almost a century ago by Ferenc Nopcsa on a set of cranial and postcranial remains from the Maastrichtian of Vălioara (Romania). It was the first described member of the recently defined clade Allodaposuchidae, one of the closest outgroups to Crocodylia.

Attribution of the original material studied by Nopcsa to a single individual cannot be confirmed. Thus, subsequent papers considered only a fragmentary skull table as the lectotype of the species. This lectotype is no longer sufficient to support the diagnosis of a distinct species and it cannot be distinguished from most of the better-known allodaposuchids. Based on the type series alone, A. precedens is a nomen dubium.

A nearly complete skull from the Maastrichtian of Oarda de Jos (Romania), referred to A. precedens, could form the basis for a new species. Alternatively, given the widespread historical use of the name, nomenclatural stability might be better served by designating a neotype for A. precedens. The authors have chosen this avenue; applying to the ICZN asking to set aside all previous type fixations and designate the Oarda de Jos skull as the neotype for A. precedens. This specimen presents several autapomorphies and an exclusive combination of characters within Allodaposuchidae, allowing an emended diagnosis for A. precedens.

The neotype designation is of utmost importance for the objective identification of this species, recognized as the type species of Allodaposuchidae. This proposal is necessary for future phylogenetic analyses and assessments of the Upper Cretaceous crocodyliform diversity.

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13.7.18 0 comentarios

Diversidad de tortugas pleurodiras de Lo Hueco en el XVI Annual Meeting de la EAVP


Siguiendo con la recopilación de trabajos tortuguiles presentados por el Grupo de Biología Evolutiva de la UNED en el XVI encuentro anual de la EAVP, hoy toca el turno de aquel correspondiente al registro de Bothremydidae de Lo Hueco (Cuenca).

El resumen es el siguiente:

Bothremydidae is the best represented group of turtles in the coastal and freshwater Upper Cretaceous sites of southwestern Europe. Several members of Bothremydini have been identified in the Campanian-Maastrichtian record of this area. Rosasia soutoi is only known in the Portuguese record. Several taxa so far restricted to the French record were described: Polysternon provinciale, Elochelys perfecta and Foxemys mechinorum. Polysternon atlanticum was defined in the Spanish upper Campanian site of Laño (Burgos), being unknown outside of this locality. The only species recognized in more than one country is Iberoccitanemys convenarum. It was defined by a shell from the upper Maastrichtian of Haute-Garonne (France), having been subsequently recognized in Central Spain by several well-preserved complete and partial shells from the upper Campanian-lower Maastrichtian site of Lo Hueco (Cuenca), and by isolated remains from the upper Campanian site of Armuña (Segovia).
Besides the fossils attributed to Iberoccitanemys convenarum, a plastron of a second bothremydid was found in Lo Hueco, this site being the only one in Europe where the synchronous and sympatric coexistence of two bothremydids is currently recognized. However, the limited information so far available only allowed its preliminary identification as an indeterminate member of Foxemydina.
Several unpublished remains from Lo Hueco, attributable to that second form, are presented here. This study allows its accurate systematic attribution, being recognized as Foxemys mechinorum, and, therefore, expanding both the knowledge about the diversity of Bothremydidae in the Spanish record and the paleobiogeographical distribution of this taxon so far exclusively recognized in France.

Esta presentación está relacionada con una publicación que ha sido recientemente publicada, y que fue comentada aquí.

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12.7.18 0 comentarios

Barionicinos de Morella en el XVI Annual Meeting de la EAVP


Continuamos con los trabajos presentados en el último Annual Meeting de la EAVP por miembros del Grupo de Biología Evolutiva de la UNED, nos centramos en la comunicación sobre los dinosaurios terópodos de Morella (Castelón, España). En el congreso se presentó el estudio de un conjunto de restos postcraneales, que incluyen una vértebra cervical, fragmentos de dos fémures y una tibia parcial, recogidos en niveles del Barremiense superior de la Formación Arcillas de Morella y que presentan una combinación de características compatible con los espinosáuridos barionicinos.

El resumen es el siguiente:

Megalosauroid theropods are a relatively diverse clade of basal tetanurans with a worldwide distribution. The clade includes piatnitkysaurids, megalosaurids and spinosaurids. The latter are especially well-represented in Cretaceous strata of Africa, South America, and Asia, but also in Europe, mainly in England, Portugal and Spain. Here, new postcranial remains of spinosaurid dinosaurs from the upper Barremian Arcillas de Morella Formation of Spain are described. These elements correspond to a posterior cervical vertebra, a right femur, a proximal fragment of a right femur, and a partial left tibia collected in three sites within the Mas de la Parreta Quarry at Morella (Castellón province, Spain). These remains present a combination of characters compatible with the clade of spinosaurids Baryonychinae, including the cervical vertebra with neural spine low and transversely thin and elongated zygapophyses and epipophyses. Comparison with elements assigned to Baryonyx indicates some differences between the remains from Morella and those of this genus described in the Lower Cretaceous of England, including the less ventral extension of the lateral femoral condyle relative to the medial one and the much less anteroposteriorly compressed femoral proximal end. Based on some identified differences, especially evident on the femora, the specimens from Morella can be confidently referred to a baryonychine distinct from Baryonyx. These new specimens support the previously proposed hypothesis on the presence of baryonychines in the eastern Spain and add information for the knowledge of the diversity and distribution of this clade in the Lower Cretaceous of the Iberian Peninsula.

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11.7.18 0 comentarios

El cráneo de Pelecanimimus en el XVI Annual Meeting de la EAVP


Durante el desarrollo del XVI Annual Meeting de la EAVP, los dinosaurios terópodos tuvieron un pequeño hueco entre tanto Sauroposium y Crocoposium. Durante el último día del congreso, tuvo lugar la sección "Ornithoscelida", donde se comunicaron charlas y póster tanto de terópodos como de ornitisquios. En esta sesión, Elena Cuesta, miembro del GBE, participó con una charla sobre la osteología craneal de Pelecanimimus, mostrando además resultados del primer escáner en 3D que se realiza en este ejemplar. Aunque el trabajo es preliminar ya se muestran resultados interesantes como que Pelecanimimus tiene varias sinapomorfías de Ornithomimosauria y que muestra una serie de autapomorfías ligadas a su dentición, como una dentario sin desviación anteroventral o la presencia de numerosos dientes en ambas mandíbulas.

Este es uno de los primeros trabajos sobre este maravilloso ejemplar, que aún tiene mucho que mostrarnos. Para más información sobre esta ponencia, aquí os dejamos el resumen (en inglés):

Pelecanimimus polyodon was discovered in 1993 in the Spanish Barremian fossil site of Las Hoyas, being the first ornithomimosaurian described in Europe. So far, there is no detailed description of the holotype of Pelecanimimus that is composed by the anterior half of an articulated skeleton that preserves evidence of soft-tissues as a soft occipital crest and a gular structure.

A detailed osteological description of the skull of Pelecanimimus has been carried out, and its features have been compared with those of other ornithomimosaurian. A CT scan and 3D reconstruction have allowed to decipher some features not previously available.

Pelecanimimus shares with other ornithomimosaurs an enlogated premaxilla, a sharp posterior margin of the maxilla, a well-developed jugal ramus of palatal, a hypertrophied prefrontal, and a parasphenoid bulba. However, Pelecanimimus also have several primitive features such as a subnarial foramen, a premaxillary process not reaching the antorbital fossa and a pneumatic recess in the anterior ramus of jugal. Undoubtedly, the most striking feature of Pelecanimimus is the presence of approximately 200 premaxillary, maxillary and dentary teeth, present only also in Nqwebasaurus.

Over the last 25 years, the known diversity of the ornithomimosaurs has increased throughout the world. The placement in context of Pelecanimimus features in current phylogenetic proposals is especially interesting to shed light on the feeding behaviour of Ornithomimosauria.
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Neuroanatomía de Lohuecosuchus megadontos en el XVI Annual Meeting de la EAVP


Dentro del simposio acerca de la evolución de los crocodilomorfos que tuvo lugar en el pasado XVI Annual Meeting de la EAVP, A. Serrano Martínez presentó una comunicación describiendo las cavidades internas del cráneo de Lohuecosuchus megadontos, especie procedente del yacimiento conquense de Lo Hueco. A partir de las reconstrucciones de dichas cavidades, se pudieron también realizar una serie de mediciones para estimar algunas de las capacidades neurosensoriales y cognitivas de este animal. Aquí el resumen:

The Campanian-Maastrichtian fossil site of Lo Hueco (Cuenca,Spain) has yielded abundant remains of eusuchian crocodylomorphs. Two species have been recently defined on the basis of specimens found at Lo Hueco: Agaresuchus fontisensis and Lohuecosuchus megadontos. They are members of the clade Allodaposuchidae, which comprises exclusively European species and represents one of the closest outgroups to Crocodylia.

The holotype of Lohuecosuchus megadontos is a nearly complete skull. We CT scanned it and reconstructed all its inner cavities in three dimensions. Although the specimen has undergone some deformation during diagenesis, its endocranial anatomy was amenable to digital reconstruction.

The brain and inner ear cavities, the nervous and vascular canals, as well as the morphology of the tympanic and pharyngotympanic systems and of the paranasal sinuses were compared to those of extinct and extant eusuchians, most of them belonging to the three main lineages of Crocodylia. The presence of several plesiomorphic character-states for Eusuchia, such as a flat caudodorsal surface of the cerebrum, huge lateral expansions of the intertympanic recess and a long medial pharyngeal recess, is consistent with Lohuecosuchus megadontos being an early-branching eusuchian.

The inner skull cavities of Lohuecosuchus megadontos were also quantified and analyzed to evaluate its sensory and cognitive capabilities. Our work suggests that Lohuecosuchus megadontos had neurosensorial capabilities similar to those of extant crocodilians, such as an acute sense of olfaction and a hearing most sensitive to low frequencies.

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Cosas que huelen a Camptosaurus en el XVI Annual Meeting de la EAVP


Hace unos días se presentaron en el XVI Annual Meeting de la European Association of Vertebrate Paleontologist (EAVP), los restos apendiculares y axiales hallados en tres yacimientos enclavados en la orla mesozoica portuguesa y pertenecientes a tres nuevos individuos de ornitópodos anquilopollexios.

Los resultados preliminares presentados en este congreso corroboran que la composición de ornitópodos no estiracosternos del Jurásico Superior ibérico está compuesta al menos por dos formas, una de ellas exclusiva del este registro europeo como es Draconyx loureiroi y otra estrechamente relacionada con alguna de las especies conocidas del género Camptosaurus, pero que, hasta el momento, es difícil de definir debido a lo fragmentario y, por ende, no diagnóstico material fósil conocido.

Aquí va el resumen:

The most common medium to large-sized ornithopod dinosaurs in the Late Jurassic are non-styracoste- rnan ankylopollexians. The ankylopollexian record from the Upper Jurassic of Portugal is not well-known and mainly based on fragmentary material from few fossil-sites located in the Lusitanian Basin. To date the presence of two species have been documented: Draconyx loureiroi and Camptosaurus aphanoecetes. In this context ankylopollexians discoveries in the Lusitanian Basin are noteworthy. Here additional material from three new localities is presented. Two localities have provided a set of well-pre- served caudal vertebrae, whereas a third locality have just provided an isolated femur. The former specimens (SHN 075 and SHN 074) come from the Sobral Formation at Atalaia (Lourinhã) and Praia da Amoreira-Porto Novo Formation at Atouguia da Baleia (Peniche) late Kimmeridgian-early Tithonian and late Kimmeridgian in age, respectively. The isolated femur [SHN(JJS) 073] comes from the locality of Peralta (Lourinhã. Sobral Formation, late Kimmeridgian-early Tithonian in age). Due to its fragmentary nature, the caudal vertebrae reported here cannot be assigned to none of the taxa described in the present-day Portuguese fossil record, and given the absence of diagnostic features are considered as Ankylopollexia indet. The femur from Peralta resembles those of Camptosaurus, but any autapomorphic feature can be con rmed, and lacks the autapomorphic character combination of the femur of Draconyx loureiroi. Therefore, the femur is here better to referred to Ankylopollexia indet. The new occurrences of non-styracosternan ankylopollexians indicates that medium to large-sized ornithopods were common dwellers during the Late Jurassic of southwestern Europe.

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Las tortugas de Algora en el XVI Annual Meeting de la EAVP


Como fue indicado aquí, varios investigadores del Grupo de Biología Evolutiva de la UNED defendieron algunos de sus trabajos recientes en el XVI encuentro anual de la EAVP (European Association of Vertebrate Palaeontologists), celebrado hace unos días en la localidad portuguesa de Caparica.

Uno de estos trabajos aludía a los resultados recientemente obtenidos en relación a los proyectos de investigación en proceso sobre la fauna del yacimiento de Algora (Guadalajara) y, más específicamente, en aquellos centrados en los nuevos datos sobre Algorachelus, el taxón más común en ese yacimiento.

El resumen es el siguiente:

Several Gondwana lineages of the crown Pleurodira reached Europe through diachronic Mesozoic and Cenozoic dispersion events. The oldest pleurodiran turtle known in Laurasia is the Bothremydid Algorachelus peregrinus. It was defined in the uppermost middle-lowermost upper Cenomanian site of Algora (Guadalajara, Central Spain), having subsequently been recognized in the middle Cenomanian locality of Nazaré (Central Portugal).
The first systematic excavation of relatively long duration carried out in Algora has recently been performed. As a consequence, abundant material of Algorachelus peregrinus was found. The new material analyzed here corresponds to several complete or almost complete and very well-preserved shells, including the most complete, as well as abundant articulated remains of both the carapace and the plastron. The abundance of remains allows the analysis of the general disarticulation patterns experienced by the shells of this littoral form. This study also allows the identification and characterization of several pathologies. In addition, it also improves the knowledge about the anatomy and intraspecific variability of this form.
This new information allows the evaluation of the validity of other Cenomanian bothremydids, both from Middle East and from North America. Thus, Algorachelus is identified in these regions, being represented in both the early or middle Cenomanian of Palestine, and in the uppermost Cenomanian of Utah. A different species is identified in each of the three continents where the genus Algorachelus is identified. Therefore, close biogeographical relationships are recognized, evidencing a relative fast dispersal event, corresponding to the oldest identified for a Gondwanic lineage of Pleurodira in Laurasia.

Esta presentación está relacionada con un trabajo de reciente publicación y que fue comentado aquí.
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El GBE en el XVI Annual Meeting de la EAVP


Durante la semana pasada, del 26 de Junio al 1 de Julio, tuvo lugar el XVI Annual Meeting de la EAVP (European Association of Vertebrate Palaeontologists) en la ciudad portuguesa de Caparica, en la Facultad de Ciencias y Tecnología de la Universidad Nova de Lisboa. El congreso abrió sus puertas con dos workshops, uno de fotogrametría y otro de morfometría geométrica, a los que siguieron una serie de presentaciones cortas para promover la visibilización LGBTQIA+ en ciencia y exposiciones museísticas, y una segunda edición del workshop acerca de las desigualdades de género y los estereotipos atribuidos a las mujeres en la ciencia, y concretamente en la paleontología.

Ya dentro del propio congreso, cabe destacar la gran afluencia a los tres simposios que formaron el núcleo del congreso: Evolución de crocodilomorfos, microvertebrados cuaternarios y dinosaurios saurópodos. Finalmente, durante el fin de semana se llevaron a cabo las dos salidas de campo, a los Jurásicos de la Cuenca Lusitánica y a la Cuenca del Algarve.


En esta ocasión, el Grupo de Biología Evolutiva de la UNED participó de forma masiva, enviando los siguientes trabajos:
Enhorabuena al grupo de paleontologia de la Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa (FCT NOVA) por la magnífica organización... y nos vemos en el XVII EAVP del año que viene en Bruselas....