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Abstract Connus depuis le XIXe siècle, les sables du Miocène Moyen de la région de Beaugency, Tavers et Le Bardon ont fourni des restes de grands mammifères tels que des Rhinocerotidae et des Proboscidea. Ces gisements n'ont été que sporadiquement étudiés et rapprochés temporellement de l'Orléanien supérieur (biozone MN5, c. Burdigalien terminal-Langhien). Cependant, aucune étude globale de ces gisements, couplant données géologiques et paléontologiques, n'a été réalisée. De 2022 à 2023, une campagne de collecte de données a été lancée sur le terrain (cadre structural et taphonomie) ainsi que dans les collections de paléontologie. La série géologique comprend la Formation du calcaire de Beauce (Oligocène-Aquitanien; Gigout 1974), la Formation des sables et marnes de l'Orléanais (FSMO) du Miocène Moyen (Orléanien supérieur, MN5, c. Burdigalien terminal-Langhien) ainsi qu'un placage de formations superficielles (alluvions, colluvions et limons des plateaux) du Quaternaire-Actuel. La compréhension de l'agencement géométrique des buttes-témoins des sables miocènes fait ressortir un découpage tectonique en blocs, postérieur au dépôt. Deux assemblages de vertébrés fossiles apparaissent dans cette étude: 1) la rare présence de mammifères oligocènes Ronzotherium romani Kretzoi, 1940 et Palaeogale minuta (Gervais, 1848) (remaniés dans la FSMO); et 2) un assemblage de vertébrés continentaux orléaniens (en place dans la FSMO) composé de 66 taxons de vertébrés et de 16 taxons d'invertébrés formant une association typique de la biozone MN5 (Orléanien supérieur, c. Burdigalien terminal-Langhien). Certains taxons sont représentés par des spécimens très bien préservés, comme en témoignent pour les tortues, le crâne de Chelydropsis aff. sansaniensis (Bergounioux, 1935) et la carapace de Mauremys aff. pygolopha (Peters, 1869), et pour les mammifères, les crânes du castor Steneofiber depereti Mayet, 1908 et du cheval Anchitherium aurelianense (Cuvier, 1825). La description de Mollusca euryhalins permet une meilleure compréhension de la position stratigraphique de la FSMO au moment du maximum de la transgression langhienne. Le cortège de grands mammifères des gisements de Beaugency, Tavers et Le Bardon, est l'un des plus diversifiés d'Europe. Cette faune s'intègre parfaitement dans le paysage européen dans lequel un gradient de similarité des faunes est observé d'est en ouest. Bien que les Rodentia soient très peu représentés dans les localités de la vallée de la Loire, les grands mammifères, notamment par la présence la plus septentrionale des Rhinocerotidae Hispanotherium matritense (de Prado, 1864) et Iberotherium rexmanueli (Antunes & Ginsburg, 1983), montrent une forte affinité avec ceux de la région ibérique. De par ses conditions géologiques régionales, sa diversité fossilifère exceptionnelle, la qualité de ses fossiles et son calage stratigraphique précis, cet ensemble cohérent de sites paléontologiques mérite de rentrer dans la liste nationale des sites géologiques patrimoniaux à conserver. Revision of sedimentological and biostratigraphic data from vertebrate deposits in the “Orléanais sands”, at Beaugency, Tavers and Le Bardon (Middle Miocene; Loiret, France). We present a review of sedimentological, biostratigraphic, and structural data from the vertebrate sites of the Sables de l'Orléanais (Orléans sands Formation) in Beaugency, Tavers, and Le Bardon outcrops (Middle Miocene; Loiret, France). Known since the 19th century, the Middle Miocene sands of the Beaugency, Tavers, and Le Bardon region have yielded remains of large mammals such as Rhinocerotidae and Proboscidea. These deposits have only been sporadically studied and temporally correlated with the upper Orleanian (biozone MN5, c. late Burdigalian-Langhian). However, a comprehensive study of these deposits, integrating geological and paleontological data, has yet to be conducted. Between 2022 and 2023, a data recovery campaign was launched in the field (structural context and taphonomy) and in the collections (paleontology). The geological series include the “Formation du calcaire de Beauce” (Oligocene–Aquitanian; Gigout 1974), the “Formation des sables et marnes de l'Orléanais” (FSMO) from the Middle Miocene (Orleanian, MN5, c. late Burdigalian-Langhian) as well as any surface formations (alluvium, colluvium and plateau silts) from the Quaternary. The understanding of the geometric arrangement of the Cenozoic formations highlights a tectonic division into blocks subsequent to the sedimentation. Two assemblages of fossil vertebrates are presented in this study: 1) the rare presence of Oligocene mammals Ronzotherium romani Kretzoi, 1940 and Palaeogale minuta (Gervais, 1848) (reworked in the FSMO); and 2) the assemblage of Orleanian (in situ in the FSMO) is composed of 66 taxa of vertebrates and 16 taxa of invertebrates typical of the MN5 biozone (Orleanian, c. late Burdigalian-Langhian). Some taxa are represented by well-preserved specimens, as evidenced by the skull of Chelydropsis aff. sansaniensis (Bergounioux, 1935) and the carapace of Mauremys aff. pygolopha (Peters, 1869), respectively, the skulls of the beaver Steneofiber depereti Mayet, 1908, and of the horse Anchitherium aurelianense (Cuvier, 1825) (coll. BG). The occurrence of tropical euryhaline molluscs allows a better understanding of the stratigraphic position of the FSMO during the maximum of the Langhian transgression, corresponding to the Mid-Miocene Climatic Optimum. The faunas of Beaugency, Tavers, and Le Bardon comprise the most diverse large mammal faunas in Europe that seamlessly fit into the European landscape where a gradient of faunal similarity is observed from East to West, as shown by the Dice similarity index. Although rodents are sparsely represented in the localities of the Loire Valley, large mammals, particularly evidenced by the northernmost presence of the rhinocerotids Hispanotherium matritense (de Prado, 1864) and Iberotherium rexmanueli (Antunes & Ginsburg, 1983), exhibit a strong affinity with the Iberian region. Due to its regional geological conditions, exceptional fossiliferous diversity, quality of its fossils, and precise stratigraphic calibration, this coherent set of palaeontological sites deserves to be included in the French national list of geological heritage sites to be preserved.

A number of localities in Transylvania (Romania) have yielded vertebrate microfossil remains. Two localities have been stratigraphically and biochronologically dated to the late Eocene: i.e., Treznea and Bociu. The remaining three localities are dated to the early Oligocene: Mera, Cetățuie, and Suceag. The study of cricetid rodents corroborates the presence of this family in Eastern Europe during the late Eocene, as evidenced by the species Witenia sp., Bustrania cf. B. dissimile , and Eocricetodon cf. Eo. meridionalis. The cricetids identified in the sites of the early Oligocene age show a complete turnover and a notable increase in species richness following the Eocene/Oligocene boundary, with: Eucricetodon aff. Eu. huerzeleri, Tenuicricetodon arcemis gen. et sp. nov., Pseudocricetodon cf. Ps. montalbanensis, Paracricetodon cf. Pa. walgeri, Paracricetodon kavakderensis, Paracricetodon aff. Pa. stojonovici, and Paracricetodon wentgesi. In the context of the wider biogeographic history of Europe, these new discoveries indicate that Cricetidae arrived in Europe during at least two successive migrations from Asia in the late Eocene and earliest Oligocene. These migrations may have occurred via two different migration pathways through the north and south of Europe. In a second phase, Cricetidae arriving by the northern passway spread throughout Europe, whereas Cricetidae that arrived by the southern passway remained restricted to the central and southeastern Europe. The observations made on the Cricetidae allow for the proposal of a new, more general, scenario for the Eocene–Oligocene transition on a European scale, which is more complex than the “Grande Coupure” sensu stricto as initially proposed by Stehlin in 1909.

Between many fossils of marine mammals that are kept in the collection of Museum Klok en Peel in Asten (The Netherlands), seals (Phocidae) from Liessel are well represented. Although many pieces are fragmentary due to the sand extraction process, some of them still show characteristics enabling a closer ranking in the phocid family. One of those not yet investigated fossils, a distal part of a well-preserved relatively large humerus, was studied more in detail, the results are presented here. The fossil exhibits a close resemblance to a humerus of Frisiphoca aberrata (Van Beneden, 1877), a seal species known from the Miocene of Belgium. It is the first record from The Netherlands.

Acting as a buffer between the Danube and the Black Sea, the Danube Delta plays an important role in regulating the hydro-biochemical flows of this land-sea continuum. Despite its importance, very few studies have focused on the impact of the Danube Delta on the different fluxes between the Danube and the Black Sea. One of the first step to characterize this land-sea continuum is to describe the bathymetry of the Delta. However, there is no complete, easily accessible bathymetric data on all three branches of the Delta to support hydrodynamic, biogeochemical or ecological studies. In this study, we aim to fill this gap by combining 4 different datasets, three in the river and one for the riverbanks, each varying in density and spatial distribution, to create a high-resolution bathymetry dataset. The bathymetric data was interpolated on a hybrid curvilinear-unstructured mesh with an anisotropic Inverse Distance Weighting (IDW) interpolation method. The resulting product offers resolutions ranging from 2 m in a connection zone to 100 m in one of the straight unidirectional channel. Cross validation of the dataset underlined the importance of the data source spatial pattern, with average Root Mean Square Error (RRMSE) of 0.55 %, 6.3 % and 27.6%, for river segments covered by the densest to the coarsest dataset. These error rates are comparable to those observed in bathymetry interpolation in rivers with similar source datasets. The bathymetry presented in this study is the first unique, high-resolution, comprehensive and easily accessible bathymetric model covering all three branches of the Danube Delta. The dataset is available at https://doi.org/10.5281/zenodo.14055741.

In April 2024, following the annual International Committee on Taxonomy of Viruses (ICTV) ratification vote on newly proposed taxa, the phylum Negarnaviricota was expanded by 1 new order, 1 new family, 6 new subfamilies, 34 new genera and 270 new species. One class, two orders and six species were renamed. Seven families and 12 genera were moved; ten species were renamed and moved; and nine species were abolished. This article presents the updated taxonomy of Negarnaviricota as currently accepted by the ICTV, providing an essential annual update on the classification of members of this phylum that deepen understandings of their evolution, and supports critical public health measures for virus identification and tracking.