Nuevos ejemplares de escamosos del Jurásico de Guimarota en el XXII Annual Meeting de la EAVP

Miembros del Grupo de Biología Evolutiva de la UNED han presentado durante la 22a edición de la EAVP la comunicación titulada “New squamate specimens from the Kimmeridgian Guimarota fossil site (Portugal)”. En esta comunicación se han presentado varios restos vertebrales correspondientes a un lagarto escamoso (Squamata) de Jurásico Superior de Portugal. Así, se hace una descripción anatómica y atribución sistemática preliminar de dichos elementos vertebrales, siendo atribuidos a Anguimorpha. A continuación, os dejamos el resumen perteneciente a este trabajo:

The former Guimarota coal mine, located near Leiria, in the west-central region of Portugal, is recognized as one of the most significant Upper Jurassic microvertebrate fossil localities worldwide. The vertebrate-bearing lignite coal layers have been interpreted as belonging to the Alcobaça Formation and dated to the early Kimmeridgian based on ostracods. This site is particularly renowned for its abundant and diverse fossil record of early mammalians, but a wide array of other vertebrates, including actinopterygians, amphibians, lepidosaurs, turtles, crocodyliforms, dinosaurs, and pterosaurs, have also been recovered. A set of previously undescribed, relatively well-preserved, isolated vertebrae from Guimarota, housed in the Museu Geológico (MG) in Lisbon and mislabelled as belonging to theropod dinosaurs, is described here, and its taxonomic identification is reassessed. These specimens include a cervical (MG 28959) and four dorsal (MG 28954, MG 28955, MG 28958, MG 28960) vertebrae, which are reinterpreted as belonging to small squamates. This interpretation is based on the procoelous morphology of the centra, the presence of anteroposteriorly narrow and dorsoventrally elongate paradiapophyses, and a poorly developed zygosphene-zygantrum complex (recognized in some dorsal vertebrae). The mostly straight axis of the cotyle-condyle system and the internal structure, composed of several small cavities visible in both the centrum and neural arch, indicating non-pachyostotic vertebrae, are features shared with most Pythonomorpha. However, the poorly developed zygosphene-zygantrum complex allow us to exclude the possibility that the specimens from Guimarota belong to this clade. These specimens share several features with other vertebrae from Guimarota previously attributed to indeterminate anguimorphs, including anteriorly broadened centra with ventrally smooth surfaces, as well as a shortened, broad condyle and a broad, elliptical cotyle. Based on these features, the isolated vertebrae described here are reinterpreted as belonging to Anguimorpha. The study of these specimens contributes to our understanding of the squamate diversity at Guimarota and provides new data to better characterize the poorly documented axial skeleton of the anguimorphs from this locality.

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Mas información:

• Referencia: Malafaia, E., Cabezuelo-Hernández, A., Pérez-García, A. 2025. New squamate specimens from the Kimmeridgian Guimarota fossil site (Portugal). Book of Abstracts of the XXII Annual Meeting of the European Association of Vertebrate Palaeontologists, 30 June–5 July 2025, Kraków, Poland. Palaeovertebrata, 216.

Nuevos datos sobre la anatomía de Paludidraco multidentatus en el XXII Annual Meeting de la EAVP

Miembros del Grupo de Biología Evolutiva de la UNED han presentado durante la 22a edición de la EAVP la comunicación titulada “New anatomical information about the Spanish Upper Triassic simosaurid Paludidraco multidentatus (Sauropterygia) based on an unpublished relatively complete postcranial skeleton”. En esta comunicación se ha presentado un nuevo ejemplar relativamente completo y parcialmente articulado del enigmático taxón sauropterigio español P. multidentatus. En este trabajo, se hace una presentación y comparación anatómica preliminar de los elementos preservados en este nuevo ejemplar con aquéllos presentes y ya descritos en detalle del holotipo de dicho taxón. Así, se hace hincapié en los elementos que aportarán información novedosa sobre la anatomía de este reptil marino hasta ahora únicamente descrito en base al ejemplar de referencia (holotipo). A continuación, os dejamos el resumen perteneciente a este trabajo:

Paludidraco multidentatus (Simosauridae, Sauropterygia) was defined based on a relatively complete and articulated skeleton (the holotype), including cranial and postcranial elements, and on a second skull (the paratype), from the Julian (early Carnian, Late Triassic) of El Atance fossil site (Guadalajara, central Spain). No additional individual attributable to this taxon has subsequently described. Despite the relatively good preservation of the holotype, the lack of some elements in this specimen (i.e., the middle-to-distal caudal region, zeugopodial and autopodial elements), or the partial preservation of others (i.e., coracoids, ilia, pubes, gastralia, or the proximal caudal region) have not allowed to know the complete anatomy of its postcranial skeleton. In this context, an unpublished specimen attributable to P. multidentatus, from its type locality, is presented here. The new specimen consists in a relatively complete and partially articulated postcranial skeleton, that is more robust and about 20% larger than the holotype. It preserves elements corresponding to the cervical, dorsal, sacral and proximal caudal regions; both pectoral and pelvic girdles; forelimb and hindlimb remains (including zeugopodial bones); and a well-preserved set of articulated gastral elements. As in the holotype, the new individual preserves most of its articulated dorsal region, lacking most cervical and caudal bones, although the caudal region is identified as more complete than that in the holotype. In this work, we provide a preliminary anatomical description of the skeletal elements of the new individual of P. multidentatus, with special emphasis on those that provide anatomical characters hitherto not documented for this taxon (i.e., zeugopodial elements), and on those previously poorly known (i.e., proximal regions of both pectoral and pelvic girdle elements, caudal vertebrae and ribs, gastralia, ilia), as well as on those recognized as intraspecifically variable when it is compared with the holotype.

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Más información:

• Referencia: Cabezuelo-Hernández, A., de Miguel Chaves, C., Ortega, F., Pérez-García, A. 2025. New anatomical information about the Spanish Upper Triassic simosaurid Paludidraco multidentatus (Sauropterygia) based on an unpublished relatively complete postcranial skeleton. Book of Abstracts of the XXII Annual Meeting of the European Association of Vertebrate Palaeontologists, 30 June–5 July 2025, Kraków, Poland. Palaeovertebrata, 71.

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

Como cada año, entre finales de junio y principios de julio, se celebra el congreso internacional de la European Association of Vertebrate Palaeontologists (EAVP),que en esta ocasión, se ha celebrado en la ciudad de Cracovia (Polonia). Se trata de la vigesimosegunda edición de estas importantes jornadas paleontológicas, y han discurrido entre los días 30 de junio y 5 de julio en las instalaciones del Museo Krzysztofory y el Instituto de Sistemática y Evolución de los Animales (PAS). Varios miembros del GBE de la UNED han participado este año con algunas 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. 2025. New anatomical information about the Spanish Upper Triassic simosaurid Paludidraco multidentatus (Sauropterygia) based on an unpublished relatively complete postcranial skeleton. Book of Abstracts of the XXII Annual Meeting of the European Association of Vertebrate Palaeontologists, 30 June–5 July 2025, Kraków, Poland. Palaeovertebrata, 71. 
• Malafaia, E., Cabezuelo-Hernández, A., Pérez-García, A. 2025. New squamate specimens from the Kimmeridgian Guimarota fossil site (Portugal). Book of Abstracts of the XXII Annual Meeting of the European Association of Vertebrate Palaeontologists, 30 June–5 July 2025, Kraków, Poland. Palaeovertebrata, 216.