29.9.25

Geología y paleontología del Eoceno de Argelia


Acaba de ser publicado, en la revista Geological Magazine, un trabajo en el que participa el Grupo de Biología Evolutiva de la UNED titulado: “Depositional model of the Eocene El Kohol Formation (Central Saharan Atlas, Algeria): integration of facies analysis, palaeontology and petrography”. Este artículo documenta la litoestratigrafía, la bioestratigrafía, la evolución de facies y los ambientes depositacionales de la Formación El Kohol, del Eoceno del flanco sur del Atlas Sahariano Central, en Argelia, mediante la integración de características litológicas, paleontológicas (con macrorrestos y microrrestos), y el análisis de microfacies.


Los análisis paleontológicos han aportado nuevos datos micropaleontológicos para la región, incluyendo aquellos relativos a las carófitas, ostrácodos y peces actinopterigios. Además, se han recuperado restos fragmentarios de proboscídeos terrestres y de tortugas dulceacuícolas. El análisis icnológico de la sucesión dio lugar a la identificación de cinco icnotaxones. Este estudio contribuye a mejorar la comprensión de la extensión espacial y la evolución paleoambiental de las sucesiones del Eoceno de Argelia, y ayuda a completar los registros icnológicos y paleontológicos del Eoceno del norte de África.


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26.9.25

Análisis del oído interno en tortugas botremídidas en las X Jornadas Internacionales de Salas de los Infantes


Durante las X Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno, celebradas en Salas de los Infantes, se presentó en formato de póster un estudio de los oídos internos en los diferentes linajes de tortugas botremídidas. Este análisis se realizó a partir de las reconstrucciones tridimensionales de estas estructuras obtenidas a partir de la utilización de escáneres de CT. El estudio incluye varios taxones de botremídidos los cuales se han identificado como formas adaptadas a medios dulceacuícolas o marinos tanto litorales como pelágicos. En este estudio se realiza además la comparación con otras pleurodiras en las que se ha descrito el oído interno identificando algunas diferencias en la morfología de los canales semicirculares. El resumen de esta comunicación se expone a continuación:

Bothremydidae was a successful lineage of turtles within the Crown-group Pleurodira. Their representatives were widely distributed on most continents of both northern and southern hemispheres, and they were recognized from the Albian (Early Cretaceous) to the Eocene at least. All extant species of Pleurodira live in freshwater environments. However, the bothremydids occupied a wide range of aquatic habitats, not being limited to continental environments. Thus, the representatives of Cearachelyini and most members of Bothremydini were identified as freshwater turtles, while the representatives of Taphrosphyini and Nigeremydini, and also some species of Bothremydini (as the Maastrichtian Zolhafah bella), were recognized as marine forms. The proposed lifestyle for most bothremydid taxa is generally based on the interpretation of the sedimentary environments in which they were found. However, some anatomical modifications were identified as marine adaptations convergent with those observed in extant cryptodiran sea turtles, as the high-domed skulls or the elongated limb bones. The scarce neuroanatomical information available for Bothremydidae has not allowed to quantify modifications of the cranial cavities related to a particular lifestyle. Nevertheless, modifications in the endosseous labyrinth in response to adaptations for life in marine environments have been observed for different groups of reptiles. Thus, some groups of sauropterygians highly adapted to pelagic marine environments, such as plesiosaurs and sea cryptodiran turtles, have labyrinths with relatively short and wide semicircular canals. In contrast, Triassic sauropterygians adapted to coastal areas and marine crocodiles have relatively more elongated and narrow canals.
In this work, the inner ear of different lineages of bothremydid turtles were analyzed with the aim of identifying differences in this element related to adaptations to life in diverse aquatic environments. As in previous works on neuroanatomy of turtles, the analysis of the endosseous labyrinths of the bothremydids studied here was carried out using three-dimensional reconstructions generated from high-resolution CT-scan images. These virtual models have also been compared with those of other forms of turtles (both extant and extinct pleurodires and cryptodires) to identify modifications due to adaptation to different habitats. Relative measurements of the height and length of the semicircular canals have been used to identify these differences.
Although neuroanatomical studies are still relatively scarce for Bothremydidae, they provide valuable information on the modifications in the inner ears of this lineage. Although, in general terms, some previous studies have not revealed a direct relationship between the morphology of the inner ear and the lifestyle of the turtles, the endosseous labyrinths within Bothremydidae exhibit morphological differences across the lineages within this group. Bothremydid taxa identified as freshwater forms (i.e., Cearachelyini and most of Bothremydini) showed relatively elongated and narrow semicircular canals with a ratio between the length and the height above 2.20. However, the ratios measured for other taxa (i.e., the Bothremydini Zolhafah bella, Taphrosphyini, and Nigeremydini) are below 2.00, reflecting relatively anteroposteriorly shorter and dorsoventrally higher semicircular canals in the endosseous labyrinth. Comparison with both freshwater and marine turtle forms (both pleurodires and cryptodires) allows to identify morphological differences in the inner ears of bothremydids. This analysis provides new neuroanatomical evidence that confirms the previously proposed lifestyles for the different lineages within Bothremydidae.

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Nuevos datos sobre el crecimiento de la tortuga Toremys cassiopeia en las X Jornadas Internacionales de Salas de los Infantes


En esta edición de las Jornadas se presentó el trabajo “Ontogenetic Insights into the Iberian Pleurosternid Toremys cassiopeia: New Specimens from the Lower Albian of Ariño (Spain)”, realizado en colaboración entre el Grupo de Biología Evolutiva de la UNED y la Fundación Conjunto Paleontológico de Teruel-Dinópolis, con la participación de varios investigadores de ambas instituciones. El estudio da a conocer nueve nuevos ejemplares del pleurostérnido Toremys cassiopeia, hallados en el yacimiento albiense de Ariño (Teruel). Estos incluyen, por primera vez, individuos juveniles que permiten reconstruir una secuencia de crecimiento para esta especie. El resumen es el siguiente:

Pleurosternidae is a clade of freshwater paracryptodiran turtles recorded from the Kimmeridgian (Upper Jurassic) to the Albian (Lower Cretaceous) in North America and Europe. Despite recent advances in their taxonomy and diversity (particularly in the Iberian Peninsula with the description of Selenemys lusitanica, Riodevemys inumbragigas, Toremys cassiopeia, and Pleurosternon moncayensis) ontogenetic trajectories within the group are still poorly understood. Our knowledge of intraspecific variation within this lineage also remains relatively limited, with the notable exception of Pleurosternon bullockii, which has been recently investigated in detail. This lack of data has contributed to persistent ambiguities in the anatomical interpretation and phylogenetic placement of several pleurosternid taxa.
Toremys cassiopeia was described from the lower Albian bonebed of Ariño (Teruel, Spain), and represents the stratigraphically youngest known pleurosternid worldwide. Thus, it is currently the only pleurosternid taxon confirmed beyond the Berriasian extending the stratigraphic range of the group. Until now, T. cassiopeia was only known from adult or subadult specimens, limiting developmental interpretations.
In this context, this study presents shells and shells remains of nine unpublished specimens of T. cassiopeia from the same Albian bonebed (i.e., from the type locality of the taxon), representing different ontogenetic stages, including several identifiable as juveniles. These specimens offer, for the first time in the Iberian record, a detailed ontogenetic series for a pleurosternid turtle. The comparative analysis of juvenile and adult morphologies provides critical insights into developmental changes in shell architecture and diagnostic traits across ontogeny. These results contribute to refining the diagnosis of T. cassiopeia and clarifying its intraspecific variability across ontogeny. Furthermore, the ontogenetic patterns observed are compared with those recently documented for Pleurosternon bullockii, from the British Berriasian record, providing a broader evolutionary and paleobiogeographic framework for understanding developmental trends within Pleurosternidae. Thus, by documenting ontogenetic patterns in T. cassiopeia, this study also emphasizes the need to take growth-related variation into account within the systematic frameworks of fossil turtles (an essential step toward resolving long-standing taxonomic uncertainties within Pleurosternidae).

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25.9.25

Estudio de los primeros restos de pistosaurios de Oriente Medio en las X Jornadas Internacionales de Salas de los Infantes


Miembros del Grupo de Biología Evolutiva de la UNED han presentado durante las X Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno el trabajo titulado “On the potential presence of ‘pistosaurs’ in the Middle Triassic of the Middle East”. En esta comunicación, se han presentado resultados preliminares anatómicos y sistemáticos sobre los primeros restos de pistosaurios de Israel, un grupo de reptiles marinos estrechamente emparentados con los plesiosaurios. A continuación, os dejamos el resumen perteneciente a este trabajo:

Pistosauroids (Pistosauroidea, Eosauropterygia) are a monophyletic group of sauropterygians that include the well-known plesiosaurs (i.e., Plesiosauria) as well as other basal forms from the Triassic. This clade was the most successful among Sauropterygia considering that they were globally distributed and that their fossil record spans from the probably Lower Triassic (i.e., Olenekian) to the uppermost Cretaceous (i.e., Maastrichtian). The oldest record for Triassic pistosauroids probably occurs in the Lower Triassic, with the putative pistosauroid Corosaurus alcovensis, from the Olenekian of USA or, alternatively, with the pistosauroid Kwangsisaurus orientalis, from the Olenekian or earliest Anisian of China; whereas the youngest record is represented by the plesiosaurian Rhaeticosaurus mertensi from the Rhaetian (i.e., uppermost Triassic) of Germany. Most of these Triassic forms belong to the non-plesiosaur pistosauroids, with Bobosaurus forojuliensis from the Carnian (Upper Triassic) of Italy, having been hitherto considered as the youngest known representative. Non-plesiosaur pistosauroids are informally referred to as ‘pistosaurs’, previously considered to conform a monophyletic group (i.e., the Pistosauria) or, more recently, having been considered paraphyletic. ‘Pistosaurs’ remains have been recovered from USA, China, Europe, and North Africa. Nonetheless, the knowledge about this group is relatively limited relative to other Triassic sauropterygians due to the incompleteness of their fossil record and the lack of well-preserved specimens. The most abundant and best-preserved ‘pistosaur’ material corresponds to that of Yunguisaurus liae, from the Ladinian (Middle Triassic) of China, and Pistosaurus longaevus, from the Anisian (Middle Triassic) of Germany and Poland. In this sense, ‘pistosaurs’ have never been reported from any Middle East Triassic locality, where several other Triassic sauropterygian clades occur (i.e., Placodontia, Pachypleurosauria, Nothosauria, and Simosauridae), especially in the Middle Triassic levels of Makhtesh Ramon (Negev, south Israel). In this work, we present several unpublished vertebral remains from the Muschelkalk levels (Anisian or Ladinian) of Makhtesh Ramon. The vertebral material seems incompatible with any sauropterygian clade previously described in this region, but potentially akin to the non-plesiosaurian pistosauroids (i.e., ‘pistosaurs’). We provide here both preliminary anatomical descriptions and a systematic study of this vertebral material, in addition to an anatomical comparative study with other ‘pistosaurs’.

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Nuevos datos sobre las tortugas de Riodeva (Teruel) en las X Jornadas Internacionales de Salas de los Infantes


Un único individuo de tortuga había sido, hasta ahora, documentado en la bien conocida localidad del Jurásico Superior de Barrihonda-El Húmero, en Riodeva (Teruel). Se trataba del holotipo de Riodevemys inumbragigas, el primer pleurostérnido definido en el registro español. Hasta ahora esta especie era conocida exclusivamente mediante ese espécimen, correspondiente a un espécimen adulto. Un ejemplar hasta ahora inédito de Pleurosternidae de esa misma localidad ha sido presentado en las X Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno, recientemente celebradas en Salas de los Infantes (Burgos). Al igual que el individuo previamente documentado, se trata de un esqueleto parcial, destacando, por su preservación, el caparazón. Su potencial atribución a una misma especie y, por tanto, las posibles implicaciones para conocer la ontogenia de un miembro de este linaje, son evaluadas. El resumen de esta contribución, titulada “The second individual of Pleurosternidae from the Tithonian Barrihonda-El Humero site (Riodeva, Teruel)”, es el siguiente:

One of the main lineages of stem turtles (i.e., Testudinata not attributable to the crown group Testudines) identified in the Iberian record is that of Paracryptodira. In this region, it is exclusively represented by members of the Pleurosternidae. Pleurosternidae is the only group of freshwater turtles identified in the Upper Jurassic record of both North America and Europe, showing a relatively high diversity in both regions. The North American record of this lineage is restricted to the Upper Jurassic. However, Pleurosternidae shows a notably wider temporal distribution in Europe, surviving at least until the last stage of the Lower Cretaceous (i.e., the Albian).
The information on the European members of Pleurosternidae was, until a few years ago, very limited. However, recent studies and, especially, the description of several new forms, allowed improving the knowledge on the diversity, systematic, and stratigraphic and palaeobiogeographic distributions of the forms that inhabited this continent. Although several forms are currently known for the Spanish record, the first described there was Riodevemys inumbragigas. It comes from the Kimmeridgian or Tithonian Barrihonda-El Humero fossil site, located in Riodeva, in the Teruel Province (South Iberian Basin). Other vertebrates found at this site include the sauropod Turiasaurus, the stegosaurid Dacentrurus, and the ornithopod Oblitosaurus.
Riodevemys inumbragigas was defined by a partial skeleton of an adult individual, including the almost complete shell, as well as several bones of the scapular and pelvic girdles. No other specimen has been attributed to it so far.
An unpublished partial skeleton of a turtle from the type locality of Riodevemys inumbragigas is presented here. It corresponds to a juvenile individual. Its attribution to Pleurosternidae is justified here. In fact, it is probably attributable to Riodevemys inumbragigas. However, differences in several shell characters relative to the holotype of this species are recognized. The possibility that some of these differences are due to ontogeny, but others to individual variability, are evaluated here considering the intraspecific variability known for Pleurosternidae.

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El esqueleto apendicular de Bauruemys elegans en las X Jornadas Internacionales de Salas de los Infantes


Durante la celebración en Salas de los Infantes de la décima edición de las Jornadas de Dinosaurios y su entorno, se ha presentado por parte de miembros del Grupo de Biología Evolutiva en formato poster la comunicación titulada “Appendicular skeleton of the Upper Cretaceous turtle from Brazil Bauruemys elegans (Podocnemididae, Pleurodira)”, que fue galardonada con el premio ex aequo de mejor poster de jóvenes investigadores. En este estudio se presenta la descripción preliminar de elementos del esqueleto apendicular de la tortuga pleurodira Bauruemys elegans del Cretácico de Brasil. Hasta entonces solo se conocía esta especie por su caparazón y cráneo. Los elementos estudiados corresponden con un ejemplar depositado en el Museo Nacional de Historia Natural de París. Se ha comparado el esqueleto apendicular de Bauruemys elegans con estos mismos elementos de otros taxones, tanto fósiles como actuales, de la familia Podocnemididae.

The studies of fossil turtles are normally focused on the shell and the skull. Thus, the appendicular skeleton is unknown for most fossil species. Bauruemys elegans is a podocnemidid turtle (Testudines, Pleurodira) described in the Upper Cretaceous (Turonian-Santonian) Adamantina Formation of Brazil. In Suarez (1969), the original publication where the taxon was described, the carapace, the plastron and the skull were characterised. All of them being part of the holotype, which also included both femora, coracoid and scapula, but they are not described or figured in that publication, and they remain unpublished.
Although some studies of this species were subsequently published, no appendicular elements have been so far figured or described. In the list of specimens that could be referred to this species elaborated by Gaffney et al. (2011) in the revision of the podocnemidid turtles, they noted that, in addition to the appendicular skeleton of the holotype, some other specimens also preserve elements of the appendicular skeleton. However, these elements were neither figured or described, and they remain unpublished.
We present here the first detail description of some elements of the appendicular skeleton of Bauruemys elegans. We characterised some elements of scapular and pelvic girdles, but also others of the limbs. These remains belonging to a partial unpublished individual of the species, deposited in the Muséum national d’Histoire naturelle of Paris (France). We compare these bones with those of other podocnemidids turtles, including both extinct and extant taxa.

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24.9.25

Reconstrucción de la red neurovascular del maxilar de Iguanodon en las X Jornadas Internacionales de Salas de los Infantes


En las pasadas X Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno 2025, se presentó la primera reconstrucción de la red neurovascular de la maxila de Iguanodon bernissartensis realizada mediante técnicas 3D. La morfología de la rama maxilar del nervio trigémino es muy poco conocida entre los dinosaurios no avianos. En I. bernissartensis, el canal principal es grande y los secundarios que conducen a los forámenes maxilares forman un ángulo obtuso con el canal principal. Esta morfología difiere con la presente en terópodos o saurópodos indicando que la rama maxilar es muy variable entre los dinosaurios no avianos. Además, también se encontraron diferencias en la organización de la segunda fila dorsal de canales secundarios entre I. bernissartensis y otros ornitópodos más basales debidas a la elongación de la maxila. El resumen es el siguiente:

The study of dinosaur neuroanatomy is a growing field. This field is mostly dominated by the study of the cavities of the central nervous system on the braincase. However, the increasing study of the neurovascular cavities on the rostral bones in recent years is allowing a more thorough reconstruction of the neurovascular system.
The trigeminal nerve is the primary somatosensory nerve that can be identified in the rostral bones. It stems from the forebrain and then divides into three main rostral divisions: the ophthalmic division (V1), the maxillary division (V2), and the mandibular division (V3). These branches with their corresponding arteries and veins run through bony canals in the nasal (V1), the maxilla (V2) and the dentary (v3). Its knowledge in Ornithopoda however, is so far limited to an indeterminate Dryosaurid, the elasmarian Galleonosaurus, the non hadrosaurid Styracosterna Fukuisaurus and the hadrosaurid Edmontosaurus. We explore this neurovascular network in the maxillae of the non hadrosaurid Styracosterna Iguanodon bernissartensis.
Two right maxillae (CMP11.1 and CMP11.2) retrieved from the upper Barremian “Arcillas de Morella” Formation at Morella (Castellón, Spain) were referred to the large-sized European ornithopod Iguanodon bernissartensis. To evaluate potential differences between these specimens and other dinosaurs, the maxillae were scanned using computed axial tomography (CT-scan).
The maxillary canal of the best preserved CMP11.1 has a relatively large diameter and runs longitudinally through the maxilla dorsal and labial to the roots of the teeth. This main canal branches into secondary canals that exit the maxilla through two rows of foramina in the lateral surface. The secondary canals that exit through the ventral row of seven foramina form an obtuse angle with the posterior part of main maxillary canal. The second row of four foramina emerge lateral to the main canal with a close to 90 degree angle in dorsal or ventral view. Finally, the main canal exits through the anterior maxillary foramen without branching.
Preservation of the second maxilla CMP11.2 is not as good as CMP11.1 but it also shows the same structure: a large main maxillary canal and some ventral and lateral rows of foramina. A comparison with the trigeminal V2 branch from a braincase of a different individual also referrable to I. bernissartensis shows a diameter very close to that of the posterior foramen in both maxillae, suggesting no drastic changes in the diameter of V2.
The maxillary canal has been described only in a handful of non-avian dinosaurs, especially in theropods. But among the clade Ornithopoda this structure has only described before in Galleonosaurus dorisae a basal elasmarian ornithopod from the Barremian of Australia (Wonthaggi Formation).
Both Iguanodon and Galleonosaurus share an obtuse angle of the secondary canals with the posterior portion of the main canal, however these secondary canals are noticeably longer in Iguanodon. Also, the number and distribution of the external foramina differ; in Galleonosaurus there is one predominant ventral row of foramina but in the anterior part of the maxilla the canal divides into multiple branches anterior to the antorbital fenestra. In Iguanodon the dorsal row of foramina is distributed in the anterior half of the bone, however in both taxa these dorsal foramina are located anterior to the ascending process of the maxilla. This suggests that the more spaced distribution in Iguanodon might be a product of the elongation of the anterior portion of the maxilla.
The dorsal alveolar canals in ornithopods are large and the secondary canals show a characteristic obtuse angulation which differs with the branching of these canals in other non-avian dinosaurs. The differences in the organization of the second dorsal row of secondary canals among ornithopods particularly the density, number of rows and position might be a product of the elongation of the preorbital region in Iguanodontia, absent in earlier branching ornithopods.

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El primer registro de sauropterigio procedente de Almería en las X Jornadas Internacionales de Salas de los Infantes


Miembros del Grupo de Biología Evolutiva de la UNED han presentado durante las X Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno el trabajo titulado “Preliminary systematic discussion of the first remain of Sauropterygia from Almería (southeastern Spain)”. En esta comunicación, se han presentado resultados preliminares anatómicos y sistemáticos sobre los primeros restos del grupo de reptiles marinos Sauropterygia procedentes del Triásico de Almería. A continuación, os dejamos el resumen perteneciente a este trabajo:

Sauropterygia was a successful group of aquatic reptiles with a fossil record spanning from the Olenekian (i.e., Lower Triassic) to the Maastrichtian (i.e., uppermost Cretaceous). Triassic sauropterygians can be divided into two main groups: Placodontia (i.e., durophagous forms) and Eosauropterygia, which included the most derived forms. Eosauropterygia groups the pachypleurosaurs (i.e., Pachypleurosauria); the nothosauroids (i.e., Nothosauroidea), which includes nothosaurs (i.e., Nothosauria) and simosaurs (i.e., Simosauridae); and the pistosauroids (i.e., Pistosauroidea), which includes ‘pistosaurs’ (i.e., non-plesiosaur pistosauroids) and plesiosaurs (i.e., Plesiosauria). With regards to the Spanish fossil record, all the main sauropterygian clades are represented, ranging from the Anisian (i.e., Middle Triassic) to the Maastrichtian (i.e., uppermost Cretaceous). The Spanish Triassic sauropterygian record is mostly represented by fragmentary and/or isolated remains being only diagnostic at supraspecific or suprageneric level. These remains come from Middle (i.e., Anisian and Ladinian) to Upper Triassic (i.e., probably Rhaetian) outcrops of several localities. Nonetheless, several Spanish Triassic sauropterygian species have been identified, some of them being common faunal components of other European Triassic localities (i.e., Lariosaurus balsami, Nothosaurus cf. giganteus, Nothosaurus cf. mirabilis); whereas others have been recognized as endemic Spanish forms (i.e., Parahenodus atancensis, Paludidraco multidentatus, Hispaniasaurus cranioelongatus). In this context, most of the Spanish Triassic sauropterygian remains come from the central and northeastern areas of this country, where they are represented by placodonts, pachypleurosaurs, nothosaurs, simosaurs, and pistosauroids. Conversely, sauropterygians remains in southern Spain are less abundant, having being recorded mostly from southeastern (i.e., Murcia, Jaén, Granada), but also from southwestern Spain (i.e., Huelva). Sauropterygians in southern Spain are represented by nothosaurs (i.e., Nothosaurus cf. mirabilis, Nothosaurus sp., Nothosauria indet.), pachypleurosaurs (i.e., Pachypleurosauria indet.), placodonts (i.e., Placodontia indet., Cyamodontoidea indet., Placochelyidae indet.), a probable ‘pistosaur’, a probable simosaur, and a probable nothosaur or placodont (i.e., cf. Nothosaurus/cf. Cyamodontoidea). We report here the first sauropterygian occurrence from the Triassic of Almería Province (southeastern Spain). It corresponds to an almost complete neural arch found in Sierra de Gádor in the Betic Cordillera. It is attributable to Eosauropterygia based on the presence of accessory intervertebral articulations (i.e., zygosphene-zygantrum complex) and the expanded neural arch pedicels with butterfly-shaped articulation areas for the centrum. The medium-sized neural arch displays a relative tall neural spine and short transverse processes, indicating potential nothosauroid affinities. We provide here a detailed anatomical description and the systematic study of the unpublished neural arch from Almería, in addition to a comparative analysis with the vertebrae of Eosauropterygia.

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Nuevos datos sobre las tortugas del Cretácico Inferior de Níger en las X Jornadas Internacionales de Salas de los Infantes


Siguiendo con una de las líneas de investigación que desde hace varios años se desarrollan desde el Grupo de Biología Evolutiva de la UNED, en las recientemente celebradas X Jornadas Internacionales de Salas de los Infantes se presentó una comunicación oral sobre la diversificación de las tortugas pleurodiras en el Cretácico Inferior de Gondwana, a partir de hallazgos realizados en la célebre localidad de Níger de Gadoufaoua. Concretamente, esta investigación se centra en el estudio del hasta ahora mal conocido caparazón de la forma del Aptiense Teneremys lapparenti. El resumen de esta contribución, titulada “Shell anatomy of the pleurodiran turtle Teneremys lapparenti, from the Aptian of Gadoufaoua (Niger)”, es el siguiente:

One of the most relevant fossil localities for understanding the Lower Cretaceous vertebrate record of the African continent is Gadoufaoua. This region is located in the Illumeden Basin, in the central region of Niger (Ténéré Desert, south-central region of the Sahara Desert). The fossil remains come from Aptian levels. Several lineages have been found there, including the identification of several pleurodiran turtles. This represents the oldest documented synchronistic and sympatric presence of several pleurodiran representatives in Africa, as well as one of the oldest globally. The first study of this turtle fauna was published in the early 1980s. Broin (1980) documented the presence of at least three taxa. One of them, attributed to the new turtle Taquetochelys decorata, was recognized as belonging to the extinct lineage Araripemydidae. The other two turtles from Gadoufaoua were identified as belonging to ‘Pelomedusidae (s.l.)’, a term used by her to group the podocnemidids, the pelomedusids, and the bothremydids, but not the araripemydids nor the chelids. One of them was defined as a new species, Teneremys lapparenti, but the other was referred to as Platycheloides cf. nyasae.
Taquetochelys decorata is the only species of Araripemydidae identified in Africa. Both its cranial and postcranial anatomy are well-known, so that it represents one of the best characterized Cretaceous pleurodiran turtles. Almost 40 years after the study of Broin (1980), the shell from Gadoufaoua attributed by her to Platycheloides cf. nyasae, as well as other shells and carapacial remains corresponding to the same species, were detailed studied. They were attributed to a new taxon, Francemys gadoufaouaensis, exclusive to that locality. This turtle was recognized as a representative of Pelomedusoides closely related to Podocnemidoidea, but not attributable to this clade or to any of the families so far defined. 
Teneremys lapparenti was defined by a shell fragment (preserving the partial carapace but a very small area of the plastron) associated with a skull (partially visible only in ventral view). An isolated nuchal plate was tentatively attributed to it. New information relative to the cranial anatomy of Teneremys lapparenti was subsequently provided, but not on its shell. Since Francemys gadoufaouaensis is only known from the shell, new data on this anatomical region in Teneremys lapparenti would be vital for comparing both taxa and, consequently, for better understanding how the successful radiation experienced by the Pelomedusoides in northern Gondwana during the Aptian-Cenomanian interval occurred (see Pérez-García, 2019b). In fact, the scarce shell information currently available on Teneremys lapparenti allows to recognize that it shares several derived characters in relation to other forms of Pelomedusoides with Francemys gadoufaouaensis, to which it may be closely related.
Abundant shell remains from Gadoufaoua compatible with Teneremys lapparenti, including several relatively complete shells, are available for study. This material is presented here. Thanks to the analysis of these fossils, some preliminary conclusions related to the diversity and disparity of Pelomedusoides during the Early Cretaceous, as well as concerning the precise phylogenetic position of the representatives from Gadoufaoua, are proposed. 

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23.9.25

El esqueleto postcraneal de los alodaposúquidos de Lo Hueco en las X Jornadas Internacionales de Salas de los Infantes


Durante las últimas décadas, nuestro conocimiento de los crocodiliformes eusuquios tempranos en la Península Ibérica se ha visto aumentado por una serie de hallazgos, entre los que destacan los del yacimiento de Lo Hueco, Cuenca. Allí se han descrito dos especies de cocodrilos allodaposúquidos, Lohuecosuchus megadontos y Agaresuchus fontisensis. Sin embargo, el esqueleto postcraneal de Allodaposuchidae en general y de estos dos taxones en particular todavía es relativamente desconocido. En este trabajo, presentado en las X Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno 2025, se analizan las claves para la identificación del material del esqueleto axial de Lo Hueco como perteneciente a uno u otro taxón, abriendo la puerta a una mayor comprensión de la anatomía de estos organismos y sus implicaciones evolutivas y filogenéticas. El resumen de esta contribución, cuyo título es "New insights into Allodaposuchidae vertebrae anatomy: taxonomic assignment of Lo Hueco morphotypes", es el siguiente:

Allodaposuchidae is an eusuchian clade endemic to the Late Cretaceous of Europe, which has become a keystone in our knowledge of early eusuchian evolution in recent decades. The first allodaposuchid species to be described, Allodaposuchus precedens Nopcsa, 1928, was based on fossil remains from the Maastrichtian of Romania. Since then, several new species have been described at various Campanian-Maastrichtian fossil sites in Spain and France. Most of the described allodaposuchids lack or only preserve scarce postcranial remains. Consequently, the abundant postcranial fossil remains of allodaposuchids from the Lo Hueco fossil site (Cuenca, Spain) are of particular importance in addressing the anatomy of these basal eusuchians. At the Lo Hueco site, two allodaposuchids have been described: Lohuecosuchus megadontos and Agaresuchus fontisensis. These two sympatric and synchronic species were first described using the cranial remains that were available at the time. In contrast, the postcranial anatomy of these species was only preliminarily explored in a number of studies.
Despite the recognition of two different postcranial morphotypes (appendicular and axial) among the remains of Lo Hueco, these could not be confidently assigned to either of the two allodaposuchid species from this site. In parallel, there has been a surge of interest in the postcranial skeleton of crocodylomorphs in general, and eusuchians in particular, with different aspects like their morphology, functional biology, and disparity being explored. Numerous studies have emphasized a previously underestimated disparity and locomotor complexity, with significant evolutionary implications. In this context, the importance of a deeper study of allodaposuchid postcranial anatomy is highlighted.
Following the association between a series of postcranial remains and the holotype of Agaresuchus fontisensis, along with previous work on morphotype identification, one of the vertebral morphotypes from Lo Hueco can now be confidently assigned to one of the two recognized allodaposuchid species. Consequently, the second morphotype can be reasonably attributed to the other species. This study formally establishes the taxonomic identity of the axial eusuchian morphotypes previously recognized at Lo Hueco, with the one formerly presented as “robust” being L. megadontos and the one presented as “slender” being A. fontisensis. In addition, the morphology of the vertebral elements belonging to both species is described and compared. As a consequence of these results, the axial record of the Lo Hueco allodaposuchids becomes a valuable dataset for future studies regarding the macroevolutionary transformations of the postcranial skeleton in early eusuchians.

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22.9.25

¿Cómo se desplazaría un dinosaurio cojo? Entendiendo los límites de la locomoción de un ornitópodo de la Formación Arcillas de Morella en las X Jornadas Internacionales de Salas de los Infantes


Durante las X Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno, miembros del Grupo de Biología Evolutiva de la UNED han presentado la comunicación titulada “How might a limping dinosaur move? Understanding the limits of the locomotion of an ornithopod from the Arcillas de Morella Formation (Castellón, Spain)”. En esta contribución, se han expuesto los resultados concernientes a la reconstrucción tridimensional de una cintura pélvica con anomalías anatómicas de un dinosaurio ornitópodo estiracosterno hallado de la Cantera de Mas de la Parreta, localizada en el municipio castellonense de Morella; siendo de especial interés la reconstrucción miológica en función de las marcas musculares, la descripción de las anomalías observadas y sus implicaciones en la locomoción del dinosaurio estudiado. A continuación, presentamos el resumen del trabajo:

Locomotion in non-avian dinosaurs is one of the most captivating aspects of the modern paleobiology of vertebrates. Despite the obvious constraints, the validation of biomechanical studies using fossils can be developed by a variety of methods: building of musculoskeletal models, analyzing fossilized footprints, comparing them with extant taxa, and studying the osseous elements. Among non-avian dinosaurs, a significant research on the reconstruction of inferred locomotion in styracosternan ornithopods has been conducted in recent years. Additionally, these dinosaurs are also known to have had a high number of palaeopathologies among the Mesozoic terrestrial vertebrates. Nevertheless, it is extremely rare to find pathologies or anomalous anatomical conditions affecting the mechanical processes of normal gait in any group of non-avian dinosaurs, considering the nature of the fossil record. Non-hadrosauroid styracosternan ornithopods are one of the best represented dinosaurs in the Lower Cretaceous European terrestrial vertebrate fossil record. In this context, the Arcillas de Morella Formation, in northeastern Spain, has provided a large amount of evidence for more than a decade. Among these, a nearly complete adult specimen from the Mas de la Parreta Quarry (CMP-5), characterized by several pathologies in its axial bones, exhibits an osteological anomaly in its left ilium. This anomaly consists of a markedly different morphology and proportions compared to its right counterpart. This results in a noticeable asymmetry of the pelvic girdle that affects the suprailiac crest and iliac plate muscle origins, mainly M. iliofemoralis, M. iliotibialis and possibly M. iliofibularis. Additionally, the morphology of the acetabulum would also be affected by this asymmetry. To analyze how this anomalous condition would affect the dinosaur, both 3D models of the pelvic girdle and the hindlimbs were created. Consequently, we have used photogrammetry to reconstruct the pelvis, right fibula and the first caudal vertebra of this individual. Additionally, photogrammetry was also implemented to finalize the reconstruction of the hindlimbs by utilizing bone elements from other individuals from the same fossiliferous area. These were scaled according to the proportions of the studied individual. Finally, the virtual skeleton was assembled using Blender software, establishing the areas of muscle origins and insertions. Therefore, the musculature reconstruction of this styracosternan provides a detailed examination of an unusual pelvic condition observed in a non-avian dinosaur. Regarding its lifestyle, this condition likely caused the styracosternan ornithopod to limp.

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19.9.25

Un resumen de la participación del GBE en las X Jornadas Internacionales de Salas de los Infantes


Cada tres años se dan cita en Salas de los Infantes las Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno, y este año no ha sido excepción. Entre el 3 y el 6 de septiembre de 2025 se han celebrado las X Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno en la localidad burgalesa de Salas de los Infantes, con 6 conferencias magistrales impartidas por especialistas nacionales e internacionales y una serie de actividades culturales desarrolladas junto a las Jornadas.


Finalmente, también se realizó una salida de campo a las canteras de Hontoria de la Cantera, parte del patrimonio geológico del entorno de esta localidad burgalesa. El Grupo de Biología Evolutiva de la UNED ha participado en estas jornadas con trece comunicaciones, en formato oral y póster, resumiendo los avances de varias de las líneas de investigación del grupo. El listado de trabajos es el siguiente:
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“Os Gigantes do Museu” na Noite Europeia dos Investigadores do Museu Nacional de História Natural em Lisboa


✨ Convite especial!

Junte-se a nós na Noite Europeia dos Investigadores, já esta sexta-feira, 26 de setembro de 2025, no Museu Nacional de História Natural e da Ciência em Lisboa, a partir das 17h. 

Nesta edição, trazemos a atividade “Os Gigantes do Museu”, uma viagem pela evolução dos maiores animais que habitaram a Terra e os oceanos — desde os imponentes dinossáurios saurópodes até às majestosas baleias.

Com a ajuda dos paleontólogos do MNHNC, do Instituto Dom Luiz, do Departamento de Ciências da Terra (FCUL) e do Grupo de Biología Evolutiva, poderá ver de perto fósseis extraordinários — alguns nunca antes expostos!

Venha descobrir ciência em primeira mão e viver uma noite inesquecível no Museu. 🦕🐋

Descrição da Atividade

Os Gigantes do Museu: Nesta atividade convidamos o público a explorar os fósseis “gigantes” do Museu Nacional de História Natural e da Ciência (MNHNC), bem como o espantoso mundo do gigantismo como estratégia ecológica. Focando-nos em alguns dos grupos de “gigantes” mais emblemáticos da natureza - os dinossáurios saurópodes e as baleias - pretendemos mostrar ao público como e por que razão os seus corpos evoluíram para alcançar tamanhos extremos em diferentes épocas e ambientes. Contrapondo as diferenças e semelhanças entre estes titãs terrestres e marinhos, a atividade centrar-se-á nos fatores evolutivos, fisiológicos e ecológicos que impulsionam o gigantismo. Durante esta edição da Noite Europeia dos Investigadores pretendemos dar vida a estes “gigantes” através das coleções do MNHNC, com restos fósseis “gigantes” do Jurássico Superior e do Miocénico de Portugal, isto é, fósseis com cerca de 150 a 145 e 20 a 10 milhões de anos, respectivamente. Venha conhecer especialistas em Paleontologia do MNHNC e do Instituto Dom Luiz (Faculdade de Ciências da Universidade de Lisboa) para apreciar de forma mais profunda os “gigantes” que outrora caminharam - e ainda nadam - na Terra.

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✨ ¡Invitación especial!

Únete a nosotros en la Noche Europea de los Investigadores, este viernes 26 de septiembre de 2025, en el Museo Nacional de Historia Natural y de la Ciencia en Lisboa, a partir de las 17h.

En esta edición presentamos la actividad “Los Gigantes del Museo”, un viaje por la evolución de los animales más grandes que habitaron la Tierra y los océanos — desde los imponentes dinosaurios saurópodos hasta las majestuosas ballenas.

Con la ayuda de los paleontólogos del MNHNC, del Instituto Dom Luiz, del Departamento de Ciencias de la Tierra (FCUL) y del Grupo de Biología Evolutiva (UNED), podrás ver de cerca fósiles extraordinarios — ¡algunos nunca antes expuestos!

Ven a descubrir la ciencia de primera mano y a vivir una noche inolvidable en el Museo. 🦕🐋

Descripción de la Actividad

Los Gigantes del Museo: En esta actividad invitamos al público a explorar los fósiles “gigantes” del Museo Nacional de Historia Natural y de la Ciencia (MNHNC), así como el asombroso mundo del gigantismo como estrategia ecológica. Centrando la atención en algunos de los grupos de “gigantes” más emblemáticos de la naturaleza —los dinosaurios saurópodos y las ballenas— queremos mostrar al público cómo y por qué sus cuerpos evolucionaron hasta alcanzar tamaños extremos en distintas épocas y ambientes. Contraponiendo las diferencias y semejanzas entre estos titanes terrestres y marinos, la actividad se enfocará en los factores evolutivos, fisiológicos y ecológicos que impulsan el gigantismo. Durante esta edición de la Noche Europea de los Investigadores queremos dar vida a estos “gigantes” a través de las colecciones del MNHNC, con restos fósiles “gigantes” del Jurásico Superior y del Mioceno de Portugal, es decir, fósiles de aproximadamente 150 a 145 y de 20 a 10 millones de años, respectivamente. Ven a conocer a especialistas en Paleontología del MNHNC y del Instituto Dom Luiz (Facultad de Ciencias de la Universidad de Lisboa) para apreciar más de cerca a los “gigantes” que caminaron en el pasado —y que todavía nadan— en la Tierra.

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  • O programa pode ser consultado em / El programa puede ser consultado en: https://noitedosinvestigadores.org/
  • Localização / Localización: https://www.museus.ulisboa.pt/
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8.9.25

El impacto del clima en los patrones de biodiversidad de los saurópodos diplodocoideos en el IV CPEG/III CPB


Entre el 27 de julio y el 1 de agosto, se celebraron conjuntamente la cuarta conferencia Crossing the Paleontological-Ecological Gap y el tercer simposio Conservation Paleobiology, en la Universidad de Zúrich, Suiza. El objetivo de estos dos encuentros internacionales es reunir a investigadores de paleontología y ecología para promover el intercambio de ideas, datos y métodos que se utilizan en ambas disciplinas, pero rara vez de forma conjunta. Del mismo modo, también pretenden fomentar la inclusión de datos paleobiológicos y ecológicos en el desarrollo de estrategias y planes de conservación, gestión y recuperación de la biodiversidad.


El primer día de la conferencia se dedicó íntegramente a talleres sobre diferentes temas, desde el desarrollo de buenas prácticas de ciencia abierta y el uso del aprendizaje profundo para análisis macroevolutivos, hasta el uso de la narración como herramienta de comunicación científica y la importancia de pensar más allá del modelo de «trabajo para toda la vida». Los cuatro días siguientes se dedicaron a comunicaciones orales (incluidas ponencias magistrales), y la sesión de comunicaciones en formato póster tuvo lugar el segundo día de la conferencia. En ella, el Grupo de Biología de la UNED estuvo representado por la estudiante de doctorado Joana Órfão (IDL/FCUL y GBE), que presentó una comunicación titulada «Climate's impact on the biodiversity patterns of Diplodocoidea during the Jurassic-Cretaceous transition» (El impacto del clima en los patrones de biodiversidad de Diplodocoidea durante la transición del Jurásico al Cretácico), parte de su tesis doctoral.


Este estudio explora los patrones de diversidad a largo plazo de los Diplodocoidea, un importante grupo de dinosaurios herbívoros de cuello largo. Mediante el análisis de registros fósiles, los investigadores descubrieron que dos subgrupos, los Dicraeosauridae y los Diplodocidae, alcanzaron su máxima diversidad durante el Jurásico tardío, pero disminuyeron drásticamente a lo largo del límite entre el Jurásico y el Cretácico. Por el contrario, los Rebbachisauridae cobraron importancia durante el Cretácico temprano y medio, lo que sugiere un cambio en los tipos de saurópodos que dominaron a lo largo del tiempo. Para comprender qué impulsó estos cambios, los investigadores también analizaron los datos climáticos y descubrieron que cada subgrupo de Diplodocoidea prefería condiciones ambientales ligeramente diferentes. Esto indica que el clima pudo haber desempeñado un papel importante en la configuración del lugar y el momento en que estos dinosaurios podían prosperar, y ayuda a explicar la transición en el dominio de los saurópodos a lo largo de los períodos geológicos. El resumen es el siguiente:

Reconstructing the diversity of life through deep time is crucial for understanding the evolution of life, as well as the mechanisms behind extinction and recovery. The fossil record, in particular, provides insights into the factors influencing biodiversity, such as past climate and landmass distributions. Sauropoda, a major clade of non-avian dinosaurs, offers a unique opportunity to study long-term biodiversity patterns. These large herbivores, with diverse lineages and significant ecological roles, have an abundant fossil record and a global distribution. Research suggests a latitudinal constraint on their distribution, a peak in diversity during the Kimmeridgian-Tithonian linked to the radiation of Neosauropoda, and a shift in faunal composition during the Jurassic-Cretaceous transition. Diplodocoidea is a neosauropod group with three main subclades—Dicraeosauridae, Diplodocidae, and Rebbachisauridae—showing recognizable cranial anatomy despite varied morphology. This group underwent a faunal shift during the Jurassic-Cretaceous transition, with Rebbachisauridae seemingly replacing Flagellicaudata (Dicraeosauridae + Diplodocidae) and extending into the Early-Mid Cretaceous. In this study, we examine Diplodocoidea biodiversity patterns at the genus level using both raw taxonomic diversity and SQS (Shareholder Quorum Subsampling) metrics. Our results replicate previous findings, revealing distinct geochronological diversity patterns for Rebbachisauridae and Flagellicaudata, suggesting these patterns are biological rather than sampling artifacts. Dicraeosauridae and Diplodocidae show a diversity peak during the Kimmeridgian-Tithonian, followed by a trough across the Jurassic-Cretaceous boundary. Rebbachisauridae presents consistently high diversity from the Barremian through the Cenomanian, peaking in the Aptian (or Cenomanian if uncorrected). We also assessed the influence of climate variables as drivers of Diplodocoidea biogeographic distribution, using PCA, UMAP and t-SNE methods. Our findings suggest that each clade occupied distinct climatic niches, indicating different ecological constraints and highlighting the role of climate in the Jurassic-Cretaceous sauropod faunal transition.

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