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Integration of new data in sedimentology, micropalaeontology and organic carbon isotope analysis of upper Ypresian strata in central Belgium (Zemst hole) enables differentiation of a series of biotic events and carbon isotope trends, which are believed to be associated with the 1.5-million-year-long period of global warming, known as the Early Eocene Climatic Optimum (EECO). The relatively low values in δ13Corg (-26.5‰ to -27.1‰) in the interval from the Panisel Sand to the Merelbeke Clay Members (upper NP12-lower NP13) are shown to be coinciding with a fairly high frequency in Apectodinium (>3%, up to 14%) and a Discoaster-bloom (16%-50%, essentially D. kuepperi). This is quite analogous, although less prominent, to what has been observed during the Paleocene- Eocene Thermal Maximum (PETM: Apectodinium abundance of 75% at middle and high latitudes and Discoaster blooms in tropical areas). The abrupt positive shift of up to 1‰ in δ13Corg values at the base of the overlying Pittem Clay Member (mid-NP13, mid-chron C22r), which is coincident with the virtual disappearances of Apectodinium (<0.1%) and Discoaster (<0.5%) seems to mark the end of the EECO in the southern North Sea Basin. The Zemst data allow the identification of the NP12/NP13 boundary, virtually coinciding with chron C23n/C22r boundary, at the depositional break between the Panisel Sand Member and the overlying Kwatrecht Member. The new data also allow to substantially refine the calcareous nannofossil stratigraphy during Biochron NP15 (mid-Lutetian) at middle latitudes. This is corroborated by additional data from Belgium, which furthermore reveal that the primary criterion for identifying the base of the Lutetian (LO of Blackites inflatus), as adopted in the Gorrondatxe GSSP (Spain), cannot be applied in the North Sea Basin s.s. (excluding the Paris Basin) and that there is an urgent need for defining appropriate substitutes for this boundary at these latitudes.

ABSTRACT Although recognized as an outstanding hotspot of biodiversity for both flora and fauna, the Mercantour massif remains almost totally unexplored for its groundwater fauna. This work reports the first overview on groundwater oligochaete assemblages of the “Parc du Mercantour” after a standardized exploration of both consolidated (fractured massif) and unconsolidated (porous) aquifers. About 40 species of oligochaetes were found in 49 stations representative of the main hydrogeological basins of the “Parc du Mercantour”, from both spring and hyporheic zone habitats. Five stygobiont species are identified, probably all new to science, of which two species are formally described, Aberrantidrilus stephaniae n. gen., n. sp. (Naididae, Phallodrilinae) and Marionina sambugarae n. sp., a species belonging to the widespread Marionina argentea species complex (Enchytraeidae). As a result, the genus Abyssidrilus Erséus, 1992 is now restricted to its marine, abyssal species. A dozen of species can be considered as stygophiles. Most stygobiont species are recorded from hyporheic habitats, and stygophiles have a more balanced distribution between both kinds of habitats. The nearly absence of stygoxene species from the hyporheic zone suggests that this habitat is less affected by the epigean environment than springs. The dominance of enchytraeids among the groundwater oligochaete fauna is here confirmed, and the lumbriculid genus Trichodrilus is also a characteristic faunistic element of the underground freshwater oligochaete communities. Lastly, the possibility that Aberrantidrilus cuspis n. comb. sensu Sambugar et al. (1999) is a complex of cryptic species is discussed in the framework of recent progress in the knowledge of groundwater biodiversity. Key words: Aquatic Clitellata, Oligochaeta, groundwater, Mercantour, new species, Aberrantidrilus n. gen., Marionina, Abyssidrilus RESUME Oligochètes (Annelida, Clitellata) des eaux souterraines du Parc du Mercantour (France), avec description d’un nouveau genre et de deux nouvelles espèces stygobiontes. Bien qu’il soit reconnu comme un remarquable point chaud de biodiversité pour sa flore et sa faune, le massif du Mercantour reste presque totalement inexploré quant à sa faune souterraine. Ce travail rapporte le premier aperçu des assemblages d’oligochètes des eaux souterraines du « Parc du Mercantour », suivant une exploration standardisée des aquifères consolidés (massif fracturé) et non consolidés (poreux). Environ 40 espèces d’oligochètes ont été trouvées dans 49 stations représentatives des principaux bassins hydrogéographiques du « Parc du Mercantour », ainsi que des sources et de la zone hyporhéique. Cinq espèces stygobiontes ont été identifiées, probablement toutes nouvelles pour la Science, parmi lesquelles deux ont été formellement décrites, Aberrantidrilus stephaniae n. gen., n. sp. (Naididae, Phallodrilinae) et Marionina sambugarae n. sp., une espèce appartenant au complexe d’espèces Marionina argentea (Enchytraeidae) à large répartition. Il en résulte que le genre Abyssidrilus Erséus, 1992 est maintenant restreint à ses espèces marines et abyssales. Une douzaine d’espèces peuvent être considérées comme stygophiles. La plupart des espèces stygobiontes proviennent des habitats hyporhéiques tandis que les stygophiles se répartissent de façon plus équilibrée entre les deux types d’habitats. La quasi absence d’espèces stygoxènes dans la zone hyporhéique suggère que cet habitat est moins affecté par l’environnement épigé que les sources. La dominance des enchytréides au sein de la faune des oligochètes des eaux souterraines est ici confirmée, ainsi que le genre Trichodrilus en tant qu’élément faunistique le plus caractéristique des communautés des oligochètes des eaux douces souterraines. Enfin, la possibilité qu’Aberrantidrilus cuspis n. comb. sensu Sambugar et al. (1999) soit un complexe d’espèces cryptiques est discutée dans le cadre des progrès récents dans la connaissance de la biodiversité des eaux souterraines. Mots clés : Clitellata aquatiques, Oligochètes, eaux souterraines, Mercantour, nouvelles espèces, Aberrantidrilus n. gen., Marionina

We describe a new large-sized species of hypercarnivorous hyainailourine–Kerberos langebadreae gen. & sp. nov.–from the Bartonian (MP16) locality of Montespieu (Tarn, France). These specimens consist of a skull, two hemimandibles and several hind limb elements (fibula, astragalus, calcaneum, metatarsals, and phalanges). Size estimates suggest K. langebadreae may have weighed up to 140 kg, revealing this species as the largest carnivorous mammal in Europe at that time. Besides its very large size, K. langebadreae possesses an interesting combination of primitive and derived features. The distinctive skull morphology of K. langebadreae reflects a powerful bite force. The postcranial elements, which are rarely associated with hyainailourine specimens, indicate an animal capable of a plantigrade stance and adapted for terrestrial locomotion. We performed the first phylogenetic analysis of hyainailourines to determine the systematic position of K. langebadreae and to understand the evolution of the group that includes other massive carnivores. The analysis demonstrates that Hemipsalodon, a North American taxon, is a hyainailourine and is closely related to European Paroxyaena. Based on this analysis we hypothesize the biogeographic history of the Hyainailourinae. The group appeared in Africa with a first migration to Europe during the Bartonian that likely included the ancestors of Kerberos, Paroxyaena and Hemipsalodon, which further dispersed into North America at this time. We propose that the hyainailourines dispersed into Europe also during the Priabonian. These migrants have no ecological equivalent in Europe during these intervals and likely did not conflict with the endemic hyaenodont proviverrines. The discovery of K. langebadreae

Multi-model ensembles for sea surface temperature (SST), sea surface salinity (SSS), sea surface currents (SSC), and water transports have been developed for the North Sea and the Baltic Sea using outputs from several operational ocean forecasting models provided by different institutes. The individual models differ in model code, resolution, boundary conditions, atmospheric forcing, and data assimilation. The ensembles are produced on a daily basis. Daily statistics are calculated for each parameter giving information about the spread of the forecasts with standard deviation, ensemble mean and median, and coefficient of variation. High forecast uncertainty, i.e., for SSS and SSC, was found in the Skagerrak, Kattegat (Transition Area between North Sea and Baltic Sea), and the Norwegian Channel. Based on the data collected, longer-term statistical analyses have been done, such as a comparison with satellite data for SST and evaluation of the deviation between forecasts in temporal and spatial scale. Regions of high forecast uncertainty for SSS and SSC have been detected in the Transition Area and the Norwegian Channel where a large spread between the models might evolve due to differences in simulating the frontal structures and their movements. A distinct seasonal pattern could be distinguished for SST with high uncertainty between the forecasts during summer. Forecasts with relatively high deviation from the multi-model ensemble (MME) products or the other individual forecasts were detected for each region and each parameter. The comparison with satellite data showed that the error of the MME products is lowest compared to those of the ensemble members.

The microbial community of spiders is little known, with previous studies focussing primarily on the medical importance of spiders as vectors of pathogenic bacteria and on the screening of known cytoplasmic endosymbiont bacteria. These screening studies have been performed by means of specific primers that only amplify a selective set of endosymbionts, hampering the detection of unreported species in spiders. In order to have a more complete overview of the bacterial species that can be present in spiders, we applied a combination of a cloning assay, DGGE profiling and high-throughput sequencing on multiple individuals of the dwarf spider Oedothorax gibbosus. This revealed a co-infection of at least three known (Wolbachia, Rickettsia and Cardinium) and the detection of a previously unreported endosymbiont bacterium (Rhabdochlamydia) in spiders. 16S rRNA gene sequences of Rhabdochlamydia matched closely with those of Candidatus R. porcellionis, which is currently only reported as a pathogen from a woodlouse and with Candidatus R. crassificans reported from a cockroach. Remarkably, this bacterium appears to present in very high proportions in one of the two populations only, with all investigated females being infected. We also recovered Acinetobacter in high abundance in one individual. In total, more than 99% of approximately 4.5M high-throughput sequencing reads were restricted to these five bacterial species. In contrast to previously reported screening studies of terrestrial arthropods, our results suggest that the bacterial communities in this spider species are dominated by, or even restricted to endosymbiont bacteria. Given the high prevalence of endosymbiont species in spiders, this bacterial community pattern could be widespread in the Araneae order.

The Middle-Late Jurassic fossil assemblage found in the Tiaojishan Formation of Liaoning Province in northeastern China has yielded unparalleled evidence on the early evolution of birds1–4. Most importantly, the identification of various feather-like integumental appendages in non-avian and stem avialan theropods has illuminated the diversity and distribution of plumage structures during their adaptive transition towards use in flight4. Epidermal traces in the Tiaojishan Formation are preserved as either faint impressions or phosphatised and carbonised residues4,5. The latter were long thought to be a product of keratin-degrading bacteria6. However, more recent interpretations have favoured fossilised melanosomes; that is, melanin-bearing cellular organelles responsible in part for the colouration of skin and its structural derivatives7. This landmark hypothesis has spawned an entirely new field of exploratory inference into dinosaurian colour5,7–11, behaviour5 and physiology12.