Participación del GBE en el II Curso de Verano sobre Paleobiogeografía en Azores

A lo largo del presente mes de julio se ha desarrollado, en la isla de Santa María, en Azores (Portugal), la segunda edición del curso de verano “Azores Summer School in Marine Island (Palaeo) Biogeography”. Durante dos semanas, lo alumnos han tenido la oportunidad de aprender, tanto mediante clases teóricas como por medio de numerosas salidas de campo, sobre paleontología, geología, zoología y biogeografía, especialmente mediante ejemplos vinculados con regiones insulares de origen volcánico. Así, las Azores suponen una oportunidad para conocer y analizar in situ estos conceptos y procesos.

Tal como ocurrió con la primera edición de este curso internacional, celebrada en verano de 2022, el Grupo de Biología Evolutiva a participado en la docencia de la nueva edición, siendo responsable de dos materias: una sobre conceptos y métodos en paleontología, y la otra relativa a la paleontología de vertebrados. La participación de investigadores de varios países, tanto de Europa como de fuera de este continente, ha permitido reunir un amplio grupo interdisciplinar de profesionales, aprovechándose el encuentro para avanzar en el desarrollo de varias líneas de trabajo vinculadas con el análisis de la biología, geología y paleontología de la Macaronesia.

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Más información:

• Imágenes (de arriba abajo): Logotipo de la nueva edición del curso de verano sobre paleobiogeografía en regiones insulares. Concentración de restos de invertebrados del Plioceno en el yacimiento paleontológico de Pedra-que-pica, en la isla de Santa María (Azores). Sección de la isla de Santa María con varias estructuras de origen volcánico, en la que destacan, en la base, las “lavas en almohada” o “pillow lavas”.

Dinosaurios y otros vertebrados mesozoicos en el XI Congresso Nacional de Geologia

Hace unos días se celebró el XI Congresso Nacional de Geologia (CNG), que ha tenido lugar en el Departamento de Ciencias de la Tierra de la Facultad de Ciencias y Tecnología de la Universidade de Coimbra del 16 al 20 de julio. Celebrado en colaboración con la Sociedade Geológica de Portugal (SGP), el evento contó con más de trescientas comunicaciones y reunió a una amplia gama de científicos/as en geología tanto nacionales como internacionales. 

Durante los cuatro días de congreso se abordó en profundidad el papel de las geociencias para afrontar los retos globales de la sociedad contemporánea, así como múltiples sesiones temáticas que debatieron sobre los avances científicos en esta área. También diferentes sesiones plenarias sobre alguno de los temas más acuciantes para la sociedad y en los que las geociencias juegan un papel fundamental. Esta edición del CNG también contó con varios cursos de capacitación, salidas de campo y talleres temáticos, que contaron con una gran asistencia. 

Por su parte, el Grupo de Biología Evolutiva de la UNED presentó varias comunicaciones que resumen algunas de las líneas de investigación en el mesozoico de la península ibérica en las que se está trabajando en estos momentos:

• Malafaia, E., Mocho, P., Escaso, F., Ortega, F. 2023. O Registo Fóssil de Vertebrados Da Região de Pombal: Contributo Para o Conhecimento Das Faunas Do Jurássico Superior Da Bacia Lusitaniana. In XI Congresso Nacional de Geologia: Geociências e Desafios Globais. Livro de Resumos. Coimbra, 16-20 Julho de 2023. ISBN: 978-989-98914-8-7, edited by F. C. Lopes, P. A. Dinis, L. V. Duarte, and P. P. Cunha, 95–96. Coimbra, Portugal: Departamento de Ciências da Terra da Universidade de Coimbra. 
• Mocho, P., Escaso, F., Marcos-Fernández, F., Páramo, A., Pérez‐García, A., Vidal, D., Ortega, F. 2023. New Discoveries from the Upper Cretaceous of the Iberian Ranges (Spain): An Input to Reconstruct the Evolutionary History of the European Titanosaurs. In XI Congresso Nacional de Geologia: Geociências e Desafios Globais. Livro de Resumos. Coimbra, 16-20 Julho de 2023. ISBN: 978-989-98914-8-7, edited by F. C. Lopes, P. A. Dinis, L. V. Duarte, and P. P. Cunha, 103–104. Coimbra, Portugal: Departamento de Ciências da Terra da Universidade de Coimbra. 
• Mocho, P., Malafaia, E., Escaso, F., Gasulla, J.M., Marcos-Fernández, F., Narváez, I., Orfao, J., Paramo, A., Vidal, D., Ortega, F. 2023. The Giant Sauropod Dinosaurs of Pombal: New Discoveries. In XI Congresso Nacional de Geologia: Geociências e Desafios Globais. Livro de Resumos. Coimbra, 16-20 Julho de 2023. ISBN: 978-989-98914-8-7, edited by F. C. Lopes, P. A. Dinis, L. V. Duarte, and P. P. Cunha, 105–106. Coimbra, Portugal: Departamento de Ciências da Terra da Universidade de Coimbra. 
• Mocho, P., Escaso, F., Marcos-Fernández, F., Páramo, A., Perez-Garcia, A., Vidal, D., Ortega, F. 2023. Sauropod Fossil Record from the Upper Barremian Arcillas de Morella Formation (Maestrat Basin, Spain). In XI Congresso Nacional de Geologia: Geociências e Desafios Globais. Livro de Resumos. Coimbra, 16-20 Julho de 2023. ISBN: 978-989-98914-8-7, edited by F. C. Lopes, P. A. Dinis, L. V. Duarte, and P. P. Cunha, 107–108. Coimbra, Portugal: Departamento de Ciências da Terra da Universidade de Coimbra.
• Santos, V. F., Audije-Gil, J., Barroso-Barcenilla, F., Berrocal-Casero, M., Callapez, P.M., Malafaia, E., Ozkaya de Juanas, S., Pereira, H., Pimentel, R., Segura, M. 2023. Theropod footprints in the Lower Cretaceous of the Algarve Basin (Porto de Mós, Lagos), Portugal. In XI Congresso Nacional de Geologia: Geociências e Desafios Globais. Livro de Resumos. Coimbra, 16-20 Julho de 2023. ISBN: 978-989-98914-8-7, edited by F. C. Lopes, P. A. Dinis, L. V. Duarte, and P. P. Cunha, 133–134. Coimbra, Portugal: Departamento de Ciências da Terra da Universidade de Coimbra.

Neochelys zamorensis en el XX Annual Meeting de la EAVP

Siguiendo con el estudio de las tortugas pleurodiras del Eoceno de la Cuenca del Duero, miembros del Grupo de Biología Evolutiva de la UNED han presentado una contribución en el XX Annual Meeting de la European Association of Vertebrate Palaeontologists (EAVP). De las dos especies del podocnemídido Neochelys identificadas actualmente en esa región, la más antigua y menos conocida es Neochelys zamorensis. Su presencia había sido, hasta ahora, únicamente confirmada a partir de material proveniente de su localidad tipo (Sanzoles, en Zamora). Sin embargo, en este trabajo se han presentado numerosos y bien preservados restos procedentes del área de Cubillos-Monfarracinos, también en Zamora, evaluándose su potencial atribución a la especie. El resumen del trabajo es el siguiente:

Podocnemididae are one of the three extant lineages of pleurodiran turtles. Podocnemidids are currently restricted to the southern hemisphere, with freshwater African and South American representatives. However, this lineage, recognized from the Late Cretaceous, reached Europe during the early Eocene, where it is represented up to the upper Eocene record. The most abundant and diverse pleurodiran genus in the European Cenozoic record is the Eocene freshwater podocnemidid Neochelys. Its youngest representatives are two Iberian species defined in the Duero Basin (Central Spain): Neochelys salmanticensis and Neochelys zamorensis. Knowledge about the former has increased thanks to recent studies. In contrast, N. zamorensis is poorly known, lacking a sufficiently detailed diagnosis and being confidently reported exclusively through scarce material from its type locality: the Lutetian levels of Sanzoles, in the Zamora Province. Abundant and well-preserved material of pleurodires was found in the Cubillos-Monfarracinos synchronous area, also in Zamora. In addition to hundreds of isolated plates, more than forty partial or relatively complete shells or sets of articulated plates, as well as many other skeletal remains, were recovered. Since N. zamorensis is only known from shell remains, those from the Cubillos-Monfarracinos area are compared to those from the type locality. Our objective is to evaluate if the same species is represented in both locations, which seems very likely. If so, knowledge about the poorly known anatomy of N. zamorensis could be greatly increased, both through this study on shells and through future analyses of other skeletal regions (especially the cranium and appendicular skeleton).

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Más información:

• Referencia: Pérez-García, A., Guerrero, A., Martín de Jesús, S., Ortega, F. 2023. Assessing the presence of the podocnemidid turtle Neochelys zamorensis outside its type locality (Sanzoles, Zamora, Central Spain). In: Alba, D.M., Marigó, J., Nacarino-Meneses, C., Villa, A. (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June–1st July 2023. Palaeovertebrata, Special Volume 1-2023: 22. DOI: 10.18563/pv.eavp2023 (p. 206).

Los titanosaurios del Campaniense-Maastrichtiense de la península ibérica en el XX Annual Meeting de la EAVP

El XX Annual Meeting de la EAVP se celebró recientemente en la ciudad de Sabadell (Catalunya, España). En esta última edición, se presentó una comunicación en formato póster sobre el trabajo encabezado por Pedro Mocho, investigador del Instituto Dom Luiz (Faculdade de Ciências, Universidade de Lisboa) y del Grupo de Biología Evolutiva de la UNED. En dicha comunicación se han explorado la presencia de nuevas formas de saurópodos titanosaurios en el Campaniense-Maastrichtiense, en particular, en el registro procedente de los yacimientos de Lo Hueco (Cuenca) y Poyos (Guadalajara) de la Formación Villalba de la Sierra. El resumen es el siguiente:

Titanosauria were the main lineage of sauropods during the Late Cretaceous, reaching a cosmopolitan distribution. In Europe, this clade is represented by many occurrences, especially in the Ibero-Armorican domain, with eight described species. However, a higher diversity has been hypothesized by many authors. The evolutionary history of these taxa is still uncertain, and their progressive inclusion in phylogenetic analyses is providing a better understanding about their affinities. In addition, the systematics of some of these titanosaurs is complex, because some are based on incomplete specimens and assemblages from multitaxic bone beds. The Campanian–Maastrichtian deposits of the Iberian Ranges are rich in titanosaurian discoveries, including the sites of Lo Hueco (Cuenca) and Poyos (Guadalajara), which are currently providing significant data on the phylogeny of the European titanosaurs. We present four new specimens from Lo Hueco that are currently in preparation and study and explore the presence of a new titanosaurian species in this quarry (distinct from Lohuecotitan pandafilandi). These specimens correspond to individuals that were found in full to partial articulation or in sets of associated elements, including almost complete sequences of dorsal-to-caudal vertebrae. Our phylogenetic analyses, including seven European titanosaurian species, suggests that lithostrotians are a diverse group in Europe during the Campanian–Maastrichtian (at least two lineages), including the probable endemic lirainosaurines and lithostrotian from a non-lirainosaurine lineage, which includes the new specimens of Lo Hueco. Some of these lineages come from dispersal events into Europe in the later part of the Early Cretaceous, probably from Gondwana.

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Más información:

• Referencia: Mocho P, Escaso F, Marcos-Fernández F, Páramo A, Vidal D, Ortega F. 2023. Exploring the presence of new titanosaurian taxa in the Campanian–Maastrichtian of the Iberian Peninsula, 173-173. In: Alba DM, Marigó J, Nacarino-Meneses C, Villa A (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June – 1st July 2023. Palaeovertebrata, Special Volume 1-23. DOI: 10.18563/pv.eavp2023

Diversidad de pleurodiras del Paleoceno de Mali en el XX Annual Meeting de la EAVP

La información sobre la diversidad de tortugas pleurodiras del registro Cenozoico de África se ha incrementado notablemente en los últimos años, especialmente mediante el estudio de miembros de tanto Podocnemididae como de Bothremydidae. En este sentido, miembros del Grupo de Biología Evolutiva de la UNED han presentado una contribución en el XX Annual Meeting de la European Association of Vertebrate Palaeontologists (EAVP) en la que analiza la diversidad de pleurodiras del Paleoceno de Mali. Varias formas son reconocidas, incluyendo algunas de gran tamaño, con adaptaciones a ambientes marinos. El resumen del trabajo es el siguiente:

Pleurodira are one of the two lineages of crown Testudines. They are currently much less diverse than the members of Cryptodira, being restricted to freshwater environments at intertropical regions of the southern continents. However, Pleurodira were very abundant and diverse in the past, with a markedly greater paleobiogeographic distribution and adaptations to a greater range of environments. One of the most successful groups of Pleurodira in the fossil record is Bothremydidae, known from the Early Cretaceous to the Miocene. This lineage was especially abundant and diverse from the Late Cretaceous to the Paleocene, being recognized on several continents. Its greatest diversity is identified in the southern hemisphere. Thus, a relevant African record is known. Several bothremydid lineages are identified on that continent, including the one that reached the largest size: Nigeremydini. Nigeremydini groups large coastal bothremydids exclusively recognized as Maastrichtian and Paleocene inhabitants of the Trans-Saharan seaway. Nigeremydini are relatively well-known through the skull, but barely through the shell. One of the countries where they are recognized is Mali, two Paleocene representatives having been defined by the skull there. A large and almost complete Paleocene shell from that country, previously attributed to Pelomedusoides indet., is here analyzed in detail. Its potential attribution to Nigeremydini is evaluated. In addition, unpublished specimens from the same area and age are also studied. Some of them appear to correspond to another lineage within the Bothremydidae. The diversity of bothremydid turtles in the Paleocene of Mali is here analyzed.

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Más información:

• Referencia: Pérez-García, A. 2023. New data on the diversity of pleurodiran turtles from the Paleocene of Mali. In: Alba, D.M., Marigó, J., Nacarino-Meneses, C., Villa, A. (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June–1st July 2023. Palaeovertebrata, Special Volume 1-2023: 22. DOI: 10.18563/pv.eavp2023 (p. 207).

Dientes de abelisauridos del Cretácico Superior de Poyos en el XX Annual Meeting de la EAVP

Durante el XX Annual Meeting de la EAVP, celebrado en Sabadell entre 26 de junio y el 1 de julio, se presentó la comunicación titulada “Abelisaurid teeth from the Upper Cretaceous of Poyos (Guadalajara, Spain)”. En este trabajo, se ha descrito una colección de dientes aislados de dinosaurios terópodos procedentes del yacimiento de Poyos y se ha discutido su identificación taxonómica con base en las características morfológicas y el análisis estadístico multivariante de sus variables morfométricas. Estos análisis han permitido identificar los materiales de Poyos como pertenecientes a un grupo de abelisáuridos con características dentales similares a las de Arcovenator escotae descrito en el Campaniense de Francia y también se ha comparado con dientes aislados en diferentes localidades del Cretácico Superior de España. A continuación, el resumen del trabajo:

The Campanian-Maastrichtian locality of Poyos (Villalba de la Sierra Formation. Guadalajara, Spain) has yielded an abundant fossil record of reptiles, mostly composed of eggs and osteological elements of sauropod dinosaurs, but also by materials attributed to turtles, crocodiles, pterosaurs, and theropod dinosaurs. Among those, elements belonging to a medium-sized theropod have been preliminarily attributed to Abelisauroidea. Here we describe a sample of isolated theropod teeth collected in Poyos and we discuss its taxonomy based on statistical and morphological analyses. The sample includes about twenty isolated, relatively complete, and well-preserved tooth crowns. They correspond to relatively large-sized teeth with crown height (CH) between 22 and 58 mm (38 mm in average) and strongly labiolingually compressed (crown base ratio = 0.6 in average). The combination of morphological and morphometric features is compatible with that described for abelisaurid lateral teeth, which bear several features that include weakly convex to almost straight distal profile of the crowns, crowns with mesial carina mostly extending to the cervix or very close to it and the distal carina centrally placed on the distal margin. The Poyos specimens are similar to the teeth associated with the holotype of Arcovenator escotae from the late Campanian of France and to some isolated teeth related to that taxon from different Upper Cretaceous localities of Spain. This analysis supports the hypothesis on the presence of a medium-sized abelisaurid in Poyos and confirms that this clade was a relatively common component on the theropod fauna from the European Late Cretaceous.

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Más información:

• Referencia: Malafaia, E., Coria, R.A., Escaso, F., Ortega, F. 2023. Abelisaurid teeth from the Upper Cretaceous of Poyos (Guadalajara, Spain). In: Alba, D.M., Marigó, J., Nacarino-Meneses, C., Villa, A. (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June– 1st July 2023. Palaeovertebrata, Special Volume 1-2023: 104. DOI: 10.18563/pv.eavp2023 (p. 49).

Análisis de los elementos pélvicos y el fémur en titanosaurios en el XX Annual Meeting de la EAVP

Dentro de la línea de investigación de evolución de los distintos módulos del esqueleto apendicular en Titanosauria, miembros del Grupo de Biología Evolutiva de la UNED presentaron la comunicación titulada: “In The Shadow Of The Colossus: Understanding The Pelvic Limb Module Evolution In Titanosauriformes”. En esta contribución se presentaron los resultados obtenidos en el análisis de los elementos pélvicos y el fémur en la línea evolutiva de Titanosauria, inlcuyendo Lohuecotitan pandafilandi. Mediante la cuantificación de la morfología por morfometría geométrica basada en landmark, se puede observar cómo covarían estas estructuras ligadas a la postura y soporte del peso corporal en titanosaurios. Esta metodología además permite observar la señal filogenética de determinados caracteres con interés en la morfología funcional del esqueleto apendicular y la evolución del tamaño hasta las formas de talla mediana del cretácico Ibero-Armoricano o los pequeños Saltasauridae derivados.

The sauropod pelvic and limb skeleton experiences an important change in the Titanosauriformes subclade with the acquisition of wide-gauge posture. It is hypothesized that it is part of the gigantism evolutionary cascade. However, recent studies indicates that the contrary, a phyletic body size reduction may be undergone in the deeply-branched titanosaurians. Such evolutionary changes are still poorly understood by scarcity of pelvic and limb skeletons of titanosaurians and the availability of scanned specimens. In this study the evolution and modularity in the pelvic limb skeleton of Titanosauriformes is approached via 3D-geometric morphometrics. A small sample of pelvic girdle and femoral specimens, representative of the Titanosauriformes lineage (e.g., Euhelopus zdanskyi; e.g., up to Saltasauridae) were digitized via stereophotogrammetry. Landmarks and semilandmark curves were sample via Slicermorph® software and analyzed in R statistical software. For evolutionary analyses we followed current phylogenetic hypotheses, summarized via supertree methodology and trimmed to the current titanosauriformes sample. The results are coherent with previous results that indicate a negate phylogenetic allometric effect and here it is discussed the covariation of the pubic-ischial module and its relationship with the limb musculature and posture in titanosaurian sauropods. Also, here it is discussed the caveats of the scarcity of pelvic sauropod sample as it does not allow to deploy stronger statistical test and its effect on our results.

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Más información:

• Referencia: Páramo, A. 2023. In The Shadow Of The Colossus: Understanding The Pelvic Limb Module Evolution In Titanosauriformes. In: Alba, D.M., Marigó, J., Nacarino-Meneses, C., Villa, A. (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June– 1st July 2023. Palaeovertebrata, Special Volume 1-2023: 22. DOI: 10.18563/pv.eavp2023 (p. 197).

Presencia de tortugas dortókidas en Gran Bretaña

Un nuevo espécimen de tortuga, identificado como el registro más antiguo de pan-Pleurodira en el Reino Unido, y correspondiente al único hallazgo de este linaje en los niveles mesozoicos de este país, ha sido presentado y publicado en un artículo publicado en la revista Cretaceous Research. Se trata del registro más antiguo de una tortuga dortókida identificado a nivel global, así como de la primera cita del grupo en Reino Unido. El nuevo espécimen, procedente del Cretácico Inferior de la Isla de Wight, en el sur de Inglaterra, está representado por un caparazón relativamente completo con numerosos elementos poscraneales preservados en su interior. Por lo tanto, este ejemplar aumenta la relativamente elevada diversidad de tortugas conocida para la Formación Wessex y extiende el rango de Dortokidae hacia el noroeste de Europa.

La tomografía computarizada ha revelado que los pequeños huesos preservados dentro del caparazón incluyen vértebras cervicales, dorsales y caudales, escápulas, huesos de la cintura pélvica y elementos apendiculares. Además, se han podido identificar relevantes caracteres relativos a la morfología interna del caparazón y del plastrón, pero también de otras regiones anatómicas. Por ejemplo, la presencia de postzigapófisis de las vértebras cervicales situadas sobre la espina neural podría apoyar la atribución del mal conocido linaje de Dortokidae al clado derivado Pleurodira. Ninguna característica permite distinguir al nuevo ejemplar de la coetánea Eodortoka morellana, de España, por lo que ha sido identificada como Eodortoka cf. morellana.

El espécimen fue encontrado ex-situ, de manera que, para evitar la existencia de dudas con respecto a su procedencia, se realizó la geocronología del relleno de calcita. Este análisis ha proporcionado la primera fecha radiométrica para la Formación Wessex, de 127,3 ± 2,7 Ma. Por tanto, el estudio confirma que la Formación Wessex de la Isla de Wight tiene una edad Hauteriviense final/Barremiense temprano.

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Más información:

• Referencia: Jacobs, M.L., Pérez-García, A., Martín-Jiménez, M., Mottram, C.M, Martill, D.M., Gale, A.S., Mattsson, O.L., Wood, C. 2023. A well preserved pan-pleurodiran (Dortokidae) turtle from the English Lower Cretaceous and the first radiometric date for the Wessex Formation (Hauterivian-Barremian) of the Isle of Wight, United Kingdom. Cretaceous Research 150, 105590.  doi: 10.1016/j.cretres.2023.105590.
• Imágenes: Caparazón y conjunto de huesos preservados (arriba). Reconstrucción de las vértebras cervicales (abajo).

La gran variabilidad de Megaloolithus siruguei y las preguntas que plantea en el XX Annual Meeting de la EAVP

El foco de la línea de investigación en biología reproductiva del equipo del Grupo de Biología Evolutiva de la UNED deja tranquilo (por ahora) al yacimiento de Poyos para centrarse en Megaloolithus siruguei, una de las ooespecies presentes en otros yacimientos de la Formación Villalba de la Sierra, como Portilla y Zafra de Záncara. El registro de esta ooespecie en la Formación muestra una elevada variabilidad en su grosor y morfología de sus nodos que excede tanto la variabilidad representada en otros yacimientos publicados como la esperable en los huevos producidos por un único taxón. Esto plantea una serie de preguntas que fueron presentadas en el 20th EAVP Meeting con el trabajo titulado “Unusual Megaloolithus siruguei eggshells from the Villalba de la Sierra Fm. (Upper Cretaceous, Cuenca, Spain)”, cuyo resumen podéis encontrar a continuación:

Megaloolithus siruguei is to date the single megaloolithid oospecies recognized at two Campanian–Maastrichtian sites of the Villalba de la Sierra Fm. (Central Iberian Ranges): Portilla and Zafra de Záncara. This oospecies has also been reported at similarly aged sites in Southern France and the Tremp Fm. (Southern Pyrenees), and as M. aff. siruguei at the coeval Sierra Perenchiza Fm. (Southeastern Iberian Ranges). Interestingly, specimens from Villalba de la Sierra Fm show an uncommon combination of eggshell thickness and node shape that may represent extreme cases among this oospecies variability. The morphometric data obtained from measuring published thin sections from France, Southern Pyrenees, and Southeastern Iberian Ranges suggest that, overall, the eggshell units from specimens of the same site or formation show a similar range of spherolith width and height (and therefore eggshell thickness). Additionally, although its nodes can be bell-shaped, wave-shaped or dome-shaped, the latter morphology is seemingly the most common. The Portilla specimens, however, show a range of thickness variation comparable to all the considered French sites altogether, and the thickness of the Zafra de Záncara specimens is below the reported thickness range of the oospecies. The dome-shaped nodes are notably less frequent in the Villalba de la Sierra Fm. specimens, and bell-shaped nodes are the dominant morphology in Zafra de Záncara. The morphological data obtained from the specimens of this Formation may contribute to the understanding of the variability of this widespread European ootaxon and its relationship with biotic and abiotic factors.

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Más información:

• Referencia: Sanguino, F., de Celis, A., Pérez-García, A., Ortega, F. 2023. Unusual Megaloolithus siruguei eggshells from the Villalba de la Sierra Fm. (Upper Cretaceous, Cuenca, Spain). In: Alba, D.M., Marigó, J., Nacarino-Meneses, C., Villa, A. (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June– 1st July 2023. Palaeovertebrata, Special Volume 1-2023: 22. DOI: 10.18563/pv.eavp2023 (p. 236).

Paleopatologías en Iguanodon de la Cantera del Mas de la Parreta en el XX Annual Meeting de la EAVP

Dentro de la línea de investigación de paleopatologías, varios miembros del Grupo de Biología Evolutiva de la UNED presentaron la comunicación titulada: “A close look to an anomalous Iguanodon bernissartensis tibial bone overgrowth”. En esta contribución, se presentan los resultados obtenidos en el análisis radiológico de la tibia patológica de un espécimen de Iguanodon bernissartensis de la cantera de Mas de la Parreta (Morella, Castellón). El uso de tecnologías de tomografía computarizada ha permitido realizar un diagnosis diferencial que revela una novedosa condición patológica dentro del registro fósil dinosauriano. El resumen es el siguiente:

The evidence of paleopathological bone lesions in large-sized ornithopod dinosaurs is nowadays increasing significantly. However, most of these findings relate to hadrosaurids, whereas the record of pathologies associated with the styracosternan Iguanodon bernissartensis are mainly reported in elements of the axial skeleton. In the Iberian record, references to large-sized styracosternan limb bone lesions are extremely rare. Here, a detailed description of a paleopathological lesion on a right tibia from the Barremian Arcillas de Morella Formation (Eastern Spain) attributed to Iguanodon bernissartensis is provided. This tibia exhibits an anomalous overgrowth area at the midshaft, covering part of its posteromedial side. Gross examination reveals a smooth and swollen surface with a well-defined lobulated morphology that is thicker distally. CT scans reveal a moderate cortical expansion (i.e., hyperdense subperiosteal bone area). Differential diagnosis includes traumatic fracture callus, infections, and neoplastic growths. The studied anomaly is tentatively consistent with osteofibrous dysplasia, a fibro-osseous tumor commonly documented in mammalian tibiae and avian tibiotarsi. In most cases, this lesion is asymptomatic, although it can also appear associated with pain and swelling in the area of the deformity. Most tumors detected in fossil amniotes are usually cartilaginous or bony, and evidence of mesenchymal bone tumors, such as the one described here, is rare even in living genera. Hence, findings like this may be of valuable interest in expanding the spectrum of possible neoplastic paleopathologies in non-avian dinosaurs.

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Más información:

• Referencia: Salas-Herrera, J., Escaso, F., Gasulla, J.M., Tosca-Segura, R., Ortega, F. 2023. A close look to an anomalous Iguanodon bernissartensis tibial bone overgrowth. In: Alba, D.M., Marigó, J., Nacarino-Meneses, C., Villa, A. (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June– 1st July 2023. Palaeovertebrata, Special Volume 1-2023: 22. DOI: 10.18563/pv.eavp2023 (p. 233).

La cintura pélvica del simosáurido Paludidraco multidentatus en el XX Annual Meeting de la EAVP

Miembros del Grupo de Biología Evolutiva de la UNED han presentado durante el 20th Annual Conference of the European Association of Vertebrate Palaeontologists, el trabajo titulado “The pelvic girdle of the simosaurid Paludidraco multidentatus holotype (Sauropterygia)” en formato póster. En esta comunicación se ha presentado un estudio anatómico comparativo de los elementos pélvicos preservados en el holotipo del taxón español P. multidentatus. La anatomía pélvica del clado Simosauridae es actualmente poco conocida y comprendida. En este trabajo, se hace una comparación anatómica preliminar de los elementos pélvicos de P. multidentatus con los de su taxón hermano, Simosaurus gaillardoti, además de con los de otros sauropterigios. A continuación, os dejamos el resumen perteneciente a este trabajo:

Simosauridae is a clade of nothosauroid eosauropterygians ranging from the Anisian or Ladinian (Middle Triassic) to the Carnian (Late Triassic) of the Western Tethys region (Middle East and Europe). This group is exclusively composed by Simosaurus gaillardoti (from the Ladinian of France and Germany), defined more than a century ago, and the recently named Paludidraco multidentatus (from the Carnian of Spain). Simosaurus gaillardoti was recognized as an active predator, in contrast with P. multidentatus, these significantly different lifestyles being reflected in both the cranial and postcranial skeleton. In this context, the latter species shows anatomical features of the postcranium interpreted as associated with adaptations for slow movement near the marine bottom and, hence with a radically different type of locomotion. Nonetheless, the postcranial anatomy of simosaurids is poorly known. Thus, the pelvic region in particular is only known for S. gaillardoti, which is represented by numerous and well-preserved remains of ilia, ischia and pubes of several individuals. The holotype of P. multidentatus corresponds to a relatively complete skeleton, which preserves most pelvic bones, so far not described. Morphological differences in the pelvic region associated with their locomotion, and derived from their interpreted radically different ecological roles, between both taxa are expected. A preliminary anatomical description of the pelvic elements preserved in the holotype of P. multidentatus and their comparison with those of its sister taxon and other sauropterygians is presented here.

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Más información:

• Referencia: Cabezuelo-Hernández, A., de Miguel Chaves, C., Ortega, F., Pérez-García, A. 2023. The pelvic girdle of the simosaurid Paludidraco multidentatus holotype (Sauropterygia). In: Alba, D.M., Marigó, J., Nacarino-Meneses, C., Villa, A. (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June– 1st July 2023. Palaeovertebrata, Special Volume 1-2023: 22. DOI: 10.18563/pv.eavp2023 (p. 49).

Inferencias en el tipo de dieta de la tortuga Algorachelus peregrina en el XX Annual Meeting de la EAVP

Durante la sesión de posters del pasado XX Annual Meeting de la EAVP, celebrado en Sabadell (España), se presentó el trabajo titulado “A preliminary approach toward the feeding strategy of the Spanish Cenomanian bothremydid turtle Algorachelus peregrina”. En este trabajo se hace la reconstrucción virtual de Algorachelus peregrina junto a la musculatura relacionada con su proceso de masticación, con el objetivo de inferir en el tipo de dieta de esta especie de tortuga. Podéis ver el resumen a continuación:

The bothremydid turtle Algorachelus peregrina corresponds to the oldest representative of the crown group Pleurodira known in Europe. The type locality of this species (i.e., the Cenomanian site of Algora, in central Spain), has provided numerous complete and well-preserved shells which allowed us to recognize it as the best-represented bothremydid in the European record. Studies relating to its intraspecific shell variability and the disarticulation patterns of this element having been performed. However, there are still unknown relevant aspects of this turtle species, including those relative to its dietary preferences and feeding mechanisms. In this context, the partial skull corresponding to one of its paratypes, as well as unpublished cranial remains, allowed us to make a first approximation to the feeding strategy of A. peregrina. Thus, this study aims to estimate the muscle mass and bite force of this species. To achieve the proposed objective, we made a 3D reconstruction of the muscles of the aforementioned paratype, of a relatively complete skull and of an isolated but almost complete lower jaw, obtained from digital photogrammetry. The utilization of the Pixologic ZBrush v.2021.5 and Geomagic Studio v.2014 programs allowed us to obtain virtual meshes suitable for generating 3D reconstructions. As a result, a high muscle mass index was evidenced, with high values in masticatory force. These results coincide with the data reported in extant turtles with a durophagous diet.

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Más información:

• Referencia: Guerrero, A., Pérez-García, A. 2023. A preliminary approach toward the feeding strategy of the Spanish Cenomanian bothremydid turtle Algorachelus peregrina. In: Alba, D.M., Marigó, J., Nacarino-Meneses, C., Villa, A. (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June– 1st July 2023. Palaeovertebrata, Special Volume 1-2023: 22. DOI: 10.18563/pv.eavp2023 (p. 115).

Neuroanatomía de un nuevo ornitópodo de la Formación Arcillas de Morella en el XX Annual Meeting de la EAVP

El conocimiento sobre el sistema nervioso central en dinosaurios se encuentra extremadamente limitado, especialmente en ornitópodos. Esto es debido a la falta de preservación de tejidos blandos y de las cavidades encefálicas. En este congreso se presentó el primer estudio neuroantómico de un ornitópodo estiracosterno basal (CMP-3) de la Formación Arcillas de Morella (Castellón, España), recuperado del yacimiento paleontológico de Palau-3. La reconstrucción se realizó a partir de técnicas de tomografía axial computarizada para acceder al interior de las cavidades y poder realizar un modelo 3D del cerebro del animal, incluyendo su masa encefálica, la mayoría de pares nervios craneales, así como la carótida la cual nutre el SNC. Este modelo se comparó tanto hadrosáurios como con otros estiracosternos basales, comprobando que este nuevo espécimen presenta características únicas. Esto puede ser debido a una gran variabilidad intraespecífica en su neuroanatomía la cual nos podría ayudar a comprender la diversidad en las faunas de ornitópodos del Cretácico Inferior europeo. El resumen de la comunicación es el siguiente:

While neuroanatomy has been studied in many dinosaurs in recent years, especially theropods and sauropods, the knowledge of the central nervous system in ornithopods is far more limited. Here, we describe the endocast of a new styracosternan ornithopod specimen from the Palau-3 site, a new fossiliferous locality from the upper Barremian Arcillas de Morella Formation in Morella (northeast Spain). The neurocranium was CT-scanned, which enabled accessing previously unknown cranial anatomical information. A 3D model was generated to virtually reconstruct the morphology of the braincase and its internal cavities. The olfactory bulbs and tracts (cranial nerve I), cerebrum, pituitary body, dural expansion, cerebellum, and the medulla oblongata were identified. Also, most of the cranial nerves and the internal carotid artery were also reconstructed. In addition, this model was compared with those of other styracosternans, like Proa valdearinoensis and Iguanodon bernissartensis, and even with those of hadrosaurids like Hypacrosaurus altispinus. Compared to these, the specimen from Morella is unique in having thicker nerves and longer olfactory bulbs and tracts. The angle between cranial nerve I and the foramen magnum is more pronounced (~20°) in P. valdearinoensis and H. altispinus than in I. bernissartensis and the Palau-3 styracosternan, where it is ~10°. Among styracosternans, the new neurocranium from Palau-3 is one of the most complete and presents a series of unique features providing valuable information on the paleobiology of European late Barremian ornithopods.

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Más información:

• Referencia: Ciudad Real, M., Escaso, F., Gasulla, J.M., Ortega, F. 2023. Neuroanatomy of a new styracosternan ornithopod specimen from the Arcillas de Morella Formation (Castellón, Spain). In: Alba, D.M., Marigó, J., Nacarino-Meneses, C., Villa, A. (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June– 1st July 2023. Palaeovertebrata, Special Volume 1-2023: 22. DOI: 10.18563/pv.eavp2023 (p. 63).

Evolución de la diversidad taxonómica y disparidad morfológica de los cocodrilos eusuquios durante el Cretácico-Paleógeno en el XX Annual Meeting de la EAVP

Durante el XX congreso anual de la EAVP, celebrado en Sabadell, se presentó el trabajo titulado “Decoupling of diversity and disparity in eusuchians (Crocodyliformes, Eusuchia) across the Cretaceous-Paleogene”. Si bien lo esperable es que los procesos de diversificación taxonómica vayan acompañados de un aumento de la disparidad morfológica, no siempre ocurre así y este es el caso que se presenta en dicho trabajo. Los resultados muestran que, mientras los análisis de diversidad taxonómica señalan que existe un aumento considerable de paleodiversidad tras el límite Cretácico-Paleógeno, los análisis de disparidad morfológica muestran una disminución significativa de la disparidad. Estos nuevos análisis de disparidad morfológica se han realizado utilizando el paladar de cocodrilos eusuquios y técnicas de morfometría geométrica. A continuación, el resumen del trabajo:

Despite the widespread belief that eusuchian crocodiles possess a conserved cranial architecture, recent studies have shown that the morphological variability of the group is greater than previously thought. Our study of the taxonomic diversity of Eusuchia revealed that, during the Cretaceous, its fossil record was dominated by hylaeochampsids and allodaposuchids, endemic to Europe, whereas the first representatives of the crown group Crocodylia were scarce at this time. After the K-Pg boundary, these basal eusuchians had disappeared and a radiation of the crown group took place. However, this taxonomic turnover does not necessarily imply a significant increase in the morphological variability. Therefore, the evolution of morphological disparity has been studied using a geometric morphometric approach focused on the palate of eusuchians. This structure was chosen because of the importance of the secondary palate in the evolutionary history of Crocodyliformes. The disparity was calculated using three different metrics, each capturing different aspects such as total range, dispersion, and distance. The disparity was analysed in both extant and extinct eusuchians, and across time and space. The results indicate that morphological disparity is higher during the Cretaceous than during the Paleogene, in contrast to taxonomic diversity, which is lower during the Cretaceous than during the Paleogene. These findings suggest the presence of a decoupling event between taxonomic diversity and morphological disparity during the K-Pg transition in this crocodyliform group.

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Más información:

• Referencia: de Celis, A., Narváez, I., Ortega, F. 2023. Decoupling of diversity and disparity in eusuchians (Crocodyliformes, Eusuchia) across the Cretaceous–Paleogene. In: Alba, D.M., Marigó, J., Nacarino-Meneses, C., Villa, A. (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June– 1st July 2023. Palaeovertebrata, Special Volume 1-2023: 22. DOI: 10.18563/pv.eavp2023 (p. 66).

Biodiversidad de dinosaurios diplodocoideos en el XX Annual Meeting de la EAVP

Durante el pasado XX Annual Meeting de la EAVP celebrado en Sabadell, varios integrantes del grupo de investigación GBE-UNED presentaron nuevos datos sobre la biodiversidad de Diplodocoidea a través de la comunicación en formato póster titulada: “Diplodocoid dinosaur biodiversity: everything everywhere all at once?”. El grupo de los diplodocoideos puede dividirse en tres subclados distintos: Dicraeosauridae, Diplodocidae y Rebbachisauridae. Al analizar el registro georreferenciado de este clado de dinosaurios a lo largo del tiempo y aplicar diferentes metodologías de estudio de la biodiversidad, se ha observado que los diplodócidos están más restringidos en términos de distribución latitudinal, a diferencia de los dicraeosáuridos y los rebachisáuridos. Además, los dicraeosáuridos y los diplodócidos aparecen antes en el registro fósil en comparación con los rebaquisáuridos, que parecen surgir un poco antes de que los otros dos subclados comiencen a disminuir en términos de registros en bruto. 

Esta asincronía también está presente cuando observamos los picos de diversificación de estos subclados y en relación a la diversidad taxonómica bruta a nivel de género. Todo ello sugiere la posibilidad de que esta pueda ser una respuesta ecológica, generando cuestiones como: "¿qué factores ecológicos pueden ser responsables de este cambio?", "¿podrían estos grupos haber tenido estrategias ecológicas distintas?" o “¿qué tipo de mecanismo ecológico está presente aquí?”. Por último, aunque se suele analizar la paleodiversidad con métodos de rarefacción (como el SQS, es decir, 'Shareholder quorum subsampling') para tener en cuenta los sesgos del registro fósil, estos algoritmos requieren un número mínimo de registros para ser calculados, lo que no ocurre en la mayor parte del conjunto de datos considerado, por lo que los resultados recomiendan optar por análisis de biodiversidad tradicional cuando se trata de conjuntos de datos pequeños. El resumen de la comunicación es el siguiente:

Sauropodomorpha is one of the main clades of non-avian dinosaurs with diverse and widespread lineages. As large herbivores with a near-global distribution, they played an important ecological role in most terrestrial ecosystems. The relatively abundant sauropodomorph fossil record and their global distribution make them particularly suited to explore and analyze long-term biodiversity patterns. The Latitudinal Biodiversity Gradient (LBG) is a pattern observed in modern biodiversity in which species richness peaks in the tropics and declines toward the poles; it is considered one of the most important diversity patterns. Fossil record data can provide insight into the factors that limit or promote biodiversity, as it contains information regarding past climate and land mass distribution scenarios. Although older literature states that it is unclear if the LBG existed for Sauropodomorpha, current research suggests a presence of a latitudinal constraint for the distribution of these taxa. Diplodocoidea are a neosauropod group with a wide paleogeographic distribution, being particularly diverse during the Late Jurassic. Here, we collected Diplodocoidea fossil occurrence data from both literature and online databases (e.g., Paleobiology Database), and built latitudinal biodiversity curves using both traditional biodiversity metrics and shareholder quorum subsampling to: (1) identify the existence of biogeographic patterns that may be correlated with their phylogeny; (2) understand whether a LBG existed for this group; and (3) assess the differences between the results yielded by each biodiversity metric. Among other results, we found that biodiversity peaks for Diplodocinae, Rebbachisauridae, and Dicraeosauridae happened at different time intervals.

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Más información:

• Referencia: Órfão, J., Mocho, P., Ortega, F. 2023. Diplodocoid dinosaur latitudinal biodiversity: Everything everywhere all at once?. In: Alba, D.M., Marigó, J., Nacarino-Meneses, C., Villa, A. (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June– 1st July 2023. Palaeovertebrata, Special Volume 1-2023: 22. DOI: 10.18563/pv.eavp2023 (p. 194).

El último yacimiento de la Cantera del Mas de la Parreta en el XX Annual Meeting de la EAVP

Otro julio más nuevos materiales procedentes de la Formación Arcillas de Morella en Castellón se han presentado en la pasada 20th Annual Conference de la European Association of Vertebrate Palaeontologists (EAVP) celebrada en Sabadell (Barcelona). En concreto se han presentado de manera preliminar los restos procedentes del último yacimiento que fue encontrado en la Cantera del Mas de la Parreta, cercana a la localidad de Morella, en Castellón. Este yacimiento, CMP-MS-07, fue localizado dentro de la cantera en el área denominada Mas de Sabaté. A pesar de ser otro yacimiento en el que predominan los restos fósiles asignables a dinosaurios ornitópodos estiracosternos, también se ha localizado elementos pertenecientes a crocodiliformes como dientes pertenecientes a dinosaurios terópodos alosaurioideos. Estos últimos restos hacen de este yacimiento uno de los pocos localizados en la Cantera del Mas de la Parreta en el que se han podido asignar elementos a terópodos no espinosaurios, grupo presenta en la práctica totalidad los yacimientos de la Formación. El resumen de la comunicación es el siguiente:

For nearly two decades, the Mas de la Parreta (CMP) quarry in Morella (northeastern Spain) has yielded one of the most abundant collections of continental vertebrate fossils from the upper Barremian of Europe. Eighteen fossil assemblages were reported from this quarry, all characterized by variably complete styracosternan ornithopod remains. CMP-MS-07, located in the Mas de Sabaté area within the CMP has yielded remains of crocodyliforms and dinosaurs (ornithopods and theropods). The crocodyliform record consists of a partial tooth, a caudal vertebra, and osteoderms all of them sharing features with the members of Neosuchia. Theropods are represented by teeth tentatively referred to allosauroids. This is relevant in that most theropod remains in the Mas de Sabaté area belong to spinosaurids, while allosauroids are rare. Ornithopods are represented by cranial, axial, and appendicular elements that can be confidently referred to styracosternan iguanodontians. These materials include maxillary and dentary teeth, a partial jugal, remains of dorsal neural arches, fragmentary cervical and dorsal ribs, a caudal vertebra, haemal arches, a partial scapula, manual and pedal bones, and ossified tendons. The fauna represented at CMP-MS-07 corresponds to that known from other upper Barremian sites in the rest of the Arcillas de Morella Formation, confirming the frequent occurrence of styracosternans, but in this case, remarkably associated with allosauroid theropods.

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Más información:

• Referencia: Gasulla, J.M., Escaso, F., Malafaia, E., Mocho, P., Narváez, I., Ortega, F. 2023. A new styracosternan-bearing assemblage from the Arcillas de Morella Formation in Morella (Spain). In: Alba, D.M., Marigó, J., Nacarino-Meneses, C., Villa, A. (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June– 1st July 2023. Palaeovertebrata, Special Volume 1-2023: 22. DOI: 10.18563/pv.eavp2023 (p. 104).

Nuevos datos sobre la neuroanatomía de Diplocynodon tormis en el XX Annual Meeting de la EAVP

Miembros del GBE de la UNED, en colaboración con el Institut Català de Paleontologia Miquel Crusafont y la Universidad de Masaryk (República Checa) han presentado durante el vigésimo encuentro de la EAVP el trabajo titulado “New data on the neuroanatomy of Diplocynodon tormis (Crocodylia) from the Duero Basin (Iberian Peninsula, Spain)”, en el que se obtuvieron las reconstrucciones tridimensionales de las cavidades intracraneanas de varios ejemplares del aligatoroideo basal Diplocynodon tormis, y se compararon con las de otras especies de eusuquios. También se utilizaron estas reconstrucciones tridimensionales para estimar las capacidades neurosensoriales de estos animales, que se asemejan a los de otros aligatoroideos actuales. A continuación el resumen del trabajo:

Inner skull cavities have been overlooked in the descriptions of most fossil crocodylians until recent years. Diplocynodon, an extinct small alligatoroid that lived in Europe from the Paleocene to the Middle Miocene, is no exception to this. In order to partially fill this gap, we studied the inner cavities of the holotype of Diplocynodon tormis, recovered from Teso de la Flecha site (middle Eocene, Salamanca, Spain). The specimen is an underformed, almost complete skull with the attached jaw. Only some bones of the posterior areaof the skull are missing. The fossil was scanned using a medical CT scanner. The derived 3D model includes the paranasal air sinuses, in association with the nasal cavity,the maxillary and mandibular branches of the trigeminal nerve,the dorsal area of the forebrain and the intertympanic diverticula. These 3D reconstructions can be morphologically compared with those of members from both extant and extinct Alligatoridae and Crocodyloidea available in the literature. Our results concur with the previously-observed conservativeness of the inner cavities of crocodylians and therefore only minor morphological differences can be ascertained. The inner skull cavities of Diplocynodon tormis are more similar in shape and sensorial capabilities to alligatoroids than to crocodyloids. Further studies including other basal Alligatoroidea will be required to better understand the morphological patterns that have been relevant during the evolution of the inner skull cavities.

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Más información:

• Referencia: Serrano-Martínez, A., Luján, À.H., García-Pérez, A., Fortuny, J. 2023. New data on the neuroanatomy of Diplocynodon tormis (Crocodylia) from the Duero Basin (Iberian Peninsula, Spain). In: Alba, D.M., Marigó, J., Nacarino-Meneses, C., Villa, A. (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June– 1st July 2023. Palaeovertebrata, Special Volume 1-2023: 22. DOI: 10.18563/pv.eavp2023 (p. 250).

La cintura pélvica de la tortuga Algorachelus peregrina en el XX Annual Meeting de la EAVP

El esqueleto apendicular de las tortugas pleurodiras apenas ha sido estudiado, en parte debido a su relativa escasez en el registro fósil. En el caso de la tortuga cenomaniense Algorachelus peregrina (Pleurodira, Bothremydidae) encontramos en su localidad tipo (Algora, Guadalajara) una gran abundancia de estos restos. Entre ellos se han podido encontrar elementos pélvicos desarticulados y también articulados en los caparazones completos. Esta abundancia nos ha permitido realizar una descripción exhaustiva de la cintura pélvica de Algorachelus y una comparación de esta con la cintura pélvica de Chupacabrachelys complexus, que hasta ahora es la única tortuga botremídida en tener una descripción en profundidad de algunos de sus elementos apendiculares. Ambas cinturas pélvicas son muy similares pero existen diferencias entre ambas especies. El resumen es el siguiente:

The Cenomanian (earliest Late Cretaceous) Algorachelus peregrina is not only the oldest bothremydid turtle (Pleurodira, Podocnemidoidea) known for the European record, but it also corresponds to that represented by the largest number of specimens in the continent. Most of them come from its type locality: the uppermost middle to lowermost upper Cenomanian fossil site of Algora (Castilian Branch of the Iberian Ranges, Guadalajara Province, Castilla-La Mancha, central Spain). Partial and complete pelvic girdles of several dozen specimens have been found there, thanks to excavation campaigns carried out in recent years. In addition to isolated disarticulated or partially articulated elements of this anatomical region, numerous well-preserved pelvic bones have been found in its original position in complete and relatively complete shells. This is favoured by the firm suture of the pelvic girdle of pleurodires with both the carapace and the plastron. The abundance of carapace and plastral remains, corresponding to the sutured areas with the pelvis, allows studying the scar of the ilium in the visceral view of the dorsal shell and the scars of the ischium and pubis in the visceral view of the ventral shell. Considering this relatively extensive source of information, the detailed description of the pelvic girdle of A. peregrina is provided here. This will provide new data on the knowledge of the paleobiology of this animal, currently under study.

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Más información:

• Referencia: Gutiérrez-Gálvez, M., Pérez-García, A. 2023. The pelvic girdle of the Iberian Cenomanian turtle Algorachelus peregrina (Pleurodira, Bothremydidae). In: Alba, D.M., Marigó, J., Nacarino-Meneses, C., Villa, A. (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June– 1st July 2023. Palaeovertebrata, Special Volume 1-2023: 22. DOI: 10.18563/pv.eavp2023 (p. 116).

Un resumen de la participación del GBE en el XX Annual Meeting de la EAVP

Como de costumbre, entre finales de junio y principios de julio, se ha celebrado la reunión anual de la European Association of Vertebrate Palaeontologists (EAVP). En esta ocasión, Sabadell ha sido el destino elegido para la celebración de la vigésima edición de estas importantes jornadas paleontológicas internacionales, llevándose a cabo entre los días 26 de junio y 1 de julio en las instalaciones de Institut Català de Paleontogia Miquel Crusafont (ICP). 

Con más de doscientas personas registradas, se han presentado unas sesenta comunicaciones orales y en torno a ciento cincuenta pósters. También tuvieron lugar diferentes salidas de campos, en las cuales los participantes del congreso visitaron varios yacimientos fósiles de Cataluña, como la zona del Vallès-Penedès, con sedimentos del Mioceno. 

Diversos miembros del GBE UNED han participado este año con varias contribuciones. A continuación, os dejamos un listado de los trabajos presentados (del cuál se irá ampliando información en los sucesivos días):

• Cabezuelo-Hernández, A., de Miguel Chaves, C., Ortega, F., Pérez-García, A. 2023. The pelvic girdle of the simosaurid Paludidraco multidentatus holotype (Sauropterygia). In: Alba, D.M., Marigó, J., Nacarino-Meneses, C., Villa, A. (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June–1st July 2023. Palaeovertebrata, Special Volume 1-2023: 22. DOI: 10.18563/pv.eavp2023 (p. 49).
• Ciudad Real, M., Escaso, F., Gasulla, J.M., Ortega, F. 2023. Neuroanatomy of a new styracosternan ornithopod specimen from the Arcillas de Morella Formation (Castellón, Spain). In: Alba, D.M., Marigó, J., Nacarino-Meneses, C., Villa, A. (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June–1st July 2023. Palaeovertebrata, Special Volume 1-2023: 22. DOI: 10.18563/pv.eavp2023 (p. 63).
• de Celis, A., Narváez, I., Ortega, F. 2023. Decoupling of diversity and disparity in eusuchians (Crocodyliformes, Eusuchia) across the Cretaceous–Paleogene. In: Alba, D.M., Marigó, J., Nacarino-Meneses, C., Villa, A. (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June–1st July 2023. Palaeovertebrata, Special Volume 1-2023: 22. DOI: 10.18563/pv.eavp2023 (p. 66).
• García, M., Marqués, C., Ripoll, J., Liébana, R., Marcos-Fernández, F., Escaso, F., Ortega, F, Gasulla, J.M. 2023. Study of methods of application of glass microspheres filler on paleontological material. In: Alba, D.M., Marigó, J., Nacarino-Meneses, C., Villa, A. (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June–1st July 2023. Palaeovertebrata, Special Volume 1-2023: 22. DOI: 10.18563/pv.eavp2023 (p. 99).
• García-Zamora, E., González, A., Vidal, D. 2023. Reconstruction of the caudal and pelvic musculature of the macronarian sauropod Camarasaurus grandis. In: Alba, D.M., Marigó, J., Nacarino-Meneses, C., Villa, A. (Eds.), Book of Abstracts of the 20th Annual Conference of the European Association of Vertebrate Palaeontologists, 26th June–1st July 2023. Palaeovertebrata, Special Volume 1-2023: 22. DOI: 10.18563/pv.eavp2023 (p. 103).
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Patrones macroevolutivos de cocodrilos eusuquios y notosuquios: ¡La Tesis!

El pasado lunes 3 de julio de este 2023, en la Facultad de Humanidades de la UNED, la ya doctora Ane de Celis defendió su memoria de tesis titulada "Macroevolutionary trends in the eusuchian and notosuchian lineages (Crocodyliformes)". El resultado, por supuesto, fue la obtención del título de Doctora en Ciencias, obteniendo además la calificación de Sobresaliente...

Esta tesis ha sido dirigida por Francisco Ortega e Iván Narváez, ambos de la Universidad Nacional de Educación a Distancia (UNED). La finalización de este proceso de doctoramiento por parte de Ane supone el reconocimiento al enorme esfuerzo y trabajo llevado a cabo en los últimos años en su labor de conocer de manera más ajustada cuales son los patrones macroevolutivos que están detrás de éxito evolutivo de los cocodrilos modernos y sus antecesores más recientes. Aquí tenéis el abstract de la tesis:

The evolutionary history of crocodyliforms, an archosaur group with a rich fossil record, spans from the Triassic to the present. However, only three clades of crocodyliforms survived after the K-Pg mass extinction event: dyrosaurids, eusuchians, and notosuchians.

This dissertation presents palaeodiversity studies for eusuchians and notosuchians and analyses which abiotic or sampling factors may be associated with palaeodiversity shifts in both clades. Palaeodiversity analyses in eusuchians reveal two palaeodiversity peaks, the first during the Paleogene and mainly related to the radiation of alligatoroids in North America. The second palaeodiversity peak, which is the largest, occurs during the middle-late Miocene and is associated with the diversification of alligatorids, crocodylids and gavialids, particularly in the proto-Amazonian of South America. Palaeotemperature is one of the most important factors controlling the palaeodiversity of the eusuchian group.

Regarding the notosuchians, the study of their palaeodiversity reveals that the interpretation of their palaeodiversity patterns is highly dependent on the age assigned to the fossils of the Adamantina Formation (Late Cretaceous, Brazil). These analyses also reveal that the notosuchian fossil record is biased due to a ‘Lagerstätte effect’ linked to the presence of a large number of notosuchian specimens from the Adamantina Formation.

Moving on to the following research topic covered in this dissertation, the palate is a structure of great importance for interpreting the evolutionary history of crocodyliforms. Therefore, the evolution of the palate has been studied in eusuchians from the Late Cretaceous to the present with geometric morphometrics. The study sample includes a large ontogenetic sample of skulls representing all extant crocodylian species and a sample of eusuchian fossils covering a large part of the evolutionary tree of the group.

Analyses show that basal eusuchians, crocodyloids, alligatoroids, and gavialoids occupy distinct areas of the palatal morphospace, and that differentiation between clades is more pronounced in the present than in the past. However, disparity was higher in the past, and analyses of morphospace occupation through time reveal a shift in the occupied area of the morphospace during the Cretaceous-Paleogene transition. Furthermore, analyses of morphological disparity suggest a decoupling event between taxonomic diversity and morphological disparity in the transition from the Cretaceous to the Paleogene. Analyses assessing the impact of phylogenetic and ecological constraints on palatal morphology revealed that the relative length of the rostrum is primarily correlated with dietary category, whereas suborbital fenestrae shape morphology, among others, is constrained by phylogeny and allows the segregation of these crocodylian clades in the palatal morphospace. Evolutionary allometry analyses show that palate shape is constricted by size in most eusuchian clades. The analysis of the ontogenetic sample of extant crocodylians reveals that the palatal morphology of extant clades seems to be segregated in morphospace at least from the juvenile stage onwards. The ontogenetic trajectories of extant crocodylians show that, while most share a similar trajectory, some taxa have distinct trajectories.

Finally, the analysis of most of the mitochondrial and nuclear nucleotide sequences available for all extant crocodylians (~26000 bp) has allowed the identification of sequences with poor phylogenetic utility. These sequences were filtered out, and the remaining mitochondrial and nuclear sequences were concatenated, accounting for ~17500 bp. The resulting BI and ML trees show fully solved phylogenetic relationships among all extant crocodylians and have high support values at the nodes. This molecular tree will be particularly useful for further use in macroevolutionary research.

Y para finalizar y como es tradición en estos eventos de enorme felicidad, algarabía y alboroto, al final del acto oficial de lectura y defensa de la tesis no pudo faltar la ya típica celebración. Sólo una cosa más: ¡enhorabuena Ane!

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Más información:

• Referencia: de Celis Ruiz, A. 2023. Macroevolutionary trends in the eusuchian and notosuchian lineages (Crocodyliformes). Tesis Doctoral. UNED, Madrid.
• Imágenes: Arriba, Ane al comienzo de la defensa de su tesis; abajo, la ya doctora junto a sus directores y a los miembros de tribunal instantes después de dar por concluido el acto.