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A 55 meters thick section at Cuchia, Basque-Cantabrian Chain, North Spain, mainly formed by Lower Cretaceous Wealden facies, has been intensively investigated from the micropalaeontological viewpoint. The carbonate beds intercalated within this series yield a rich and diverse charophyte assemblages of high biostratigraphic interest, which could be studied for the first time after successful preparation following the acetolysis method.Twenty-two charophyte taxa were identified forming two distinct charophyte assemblages belonging to two successive charophyte biozones. The first charophyte assemblage, from the lower part of the studied section, is composed of Echinochara lazarii, Atopochara trivolvis var. triquetra, Globator mallardii var. trochiliscoides, Clavator grovesii var. gautieri, Clavator harrisii var. dongjingensis, C. harrisii var. harrisii, C. calcitrapus var. jiangluoensis, C. calcitrapus var. calcitrapus, Ascidiella stellata var. stellata, A. triquetra, Hemiclavator neimongolensis var. neimongolensis, H. neimongolensis var. posticecaptus, Mesochara voluta gr. voluta and Favargella sp. According to Pérez-Cano et al. (2021), such a charophyte assemblage belongs to the new Eurasian “Hemiclavator neimongolensis var. neimongolensis” biozone, late early Barremian–early late Barremian in age as calibrated by Sr isotope stratigraphy and by correlation with marine biostratigraphy.The second charophyte assemblage, which occurs in the upper part of the studied section is composed of the species E. lazarii, A. trivolvis var. triquetra, A. trivolvis var. trivolvis, C. grovesii var. jiuquanensis, C. harrisii var. dongjingensis, C. harrisii var. harrisii, C. harrisii var. reyi, Ascidiella cruciata, H. neimongolensis var. neimongolensis, H. neimongolensis var. posticecaptus, Mesochara voluta gr. voluta, Munieria grambastii, Clavatoraxis sp., Charaxis sp. and Tolypella sp. vel. Mesochara sp. According to Pérez-Cano et al. (2021), such a charophyte assemblage belongs to the new Eurasian “Clavator grovesii var. jiuquanensis” biozone, late Barremian–early Aptian in age as calibrated by Sr isotope stratigraphy and by correlation with marine biostratigraphy.As the overlaying succeeding limestones is early Aptian in age, our results allow constraining the chronostratigraphy of the Wealden series at Cuchia section to the late early Barremian– late Barremian, instead of Hauterivian–Barremian (Najarro et al., 2011) as previously thought, leading for a more detailed stratigraphic correlation of the Cuchia section to equivalent units of the Iberian plate, especially from the Iberian Chain and the Pyrenees.References.Najarro, M., Rosales, I., Martin-Chivelet, J. (2011). Major palaeoenvironmental perturbation in an Early Aptian carbonate platform: Prelude of the Oceanic Anoxic Event 1a. Sedimentary Geology 235, 50–71. https://doi.org/10.1016/j.cretres.2021.104934Pérez-Cano, J., Bover-Arnal, T., Martín-Closas, C. (2021). Barremian–early Aptian charophyte biostratigraphy revisited. Newsletters on Stratigraphy (in press). DOI: 10.1127/nos/2021/0662

The Eocene ‘‘blue hole” freshwater limestones from the bauxite cover-sequence at the Gánt karst system (Vértes Hills), Transdanubian Central Range, north-western Hungary, have yielded rich charophyte assemblages of higher taxonomic and biostratigraphic interest. The taxonomic study of this flora allows revision and emendation of the species Raskyella peckii and facilitates the definition of a new evolutionary anagenetic lineage based on three successive anagenetic varieties of this species which were formerly considered as separate species or subspecies: Raskyella peckii var. peckii (early Lutetian–early Bartonian), Raskyella peckii var. caliciformis (early Bartonian), and Raskyella peckii var. vadaszii (late Bartonian). Based on these, we propose a new local charophyte biozonation with the new Raskyella peckii Superzone (Lutetian–Bartonian), subdivided into three successive charophyte partial range zones: The ‘Raskyella peckii peckii Zone’ (Lutetian–lowermost Bartonian) is locally characterized by an assemblage of R. peckii peckii, Gyrogona caelata forma caelata, G. caelata forma monolifera and Nitellopsis (Tectochara) palaeohungarica. The ‘Raskyella peckii caliciformis Zone’ (lower Bartonian) includes the local assemblage of R. peckii var. caliciformis, G. caelata forma caelata, G. caelata forma monolifera, G. caelata forma baccata, Nitellopsis (Tectochara) palaeohungarica and Chara media. The ‘Raskyella peckii vadaszii Zone’ (upper Bartonian) is composed of the local assemblage of R. peckii var. vadaszii, G. caelata forma bicincta, G. caelata forma baccata, G. caelata forma fasciata, G. tuberosa, Psilochara polita, Psilochara sp., Chara media and Chara subcylindrica. Future research may show the new local biozonation as applicable to whole Europe and complementing the current European charophyte biozonation. Our results show that the sequences from Gánt previously regarded as upper mid-Eocene (upper Lutetian–lower Bartonian) appear to comprise a longer chronostratigraphic interval, i.e. lower Lutetian till upper Bartonian, with also has implications on the understanding of the regional stratigraphy of the Transdanubian Central Range during the Eocene.

The Postalm section in the Gosau Group (Northern Calcareous Alps) exposes pelagic deposits of northwestern Tethyan origin. We present a magneto-, bio- and chemostratigraphic assessment of this Santonian to uppermost Campanian record, as well as a cyclostratigraphic model for the Tethyan Campanian based on three independently assessed proxies; the δ13C signature, the elemental ratio of Fe and the thickness of limestone/marl couplets (Wolfgring et al., 2021).The Santonian/Campanian transition is characterised by condensed greyish packstones, the Campanian strata exhibit a succession of limestone-marl couplets that represent orbital precession of an approximate duration of 20ka. A magneto- and biostratigraphic (based on planktonic foraminifera and calcareous nannofossils) framework is supported by carbon isotope and strontium stratigraphy.The Sr isotope record matches the data for the Upper Cretaceous and suggests no major gaps in the Postalm succession. A robust cyclostratigraphic assessment of three independently assessed data series (L/M couplets, Fe and δ13C) resulted in the identification of eighteen 405 ka eccentricity cycles spanning the middle to upper Campanian (Contusotruncana plummerae to Gansserina gansseri Zones or CC17/UC15 to CC23/UC16 nannofossil zones).Carbon isotope stratigraphy identifies the LCE (Late Campanian Event) and possibly the SCBE (Santonian Campanian Boundary Event). Magneto- and biostratigraphic data, in particular the position of the top of the R. calcarata planktonic foraminifera Zone, the position of the LCE and the top of Chron C32r.1r served as primary tie points and constraints to match the floating cyclostratigraphic model to the Laskar solution and to compare it to other cyclostratigraphic solutions and reference sections for the upper Campanian.References: Wolfgring, E., Wagreich, M., Hohenegger, J., Böhm, K., Dinarès Turell, J., Gier, S., Sames, B., Spötl, C., Jin, S., 2021. An integrated multi-proxy study of cyclic pelagic deposits from the north-western Tethys: The Campanian of the Postalm section (Gosau Group, Austria), Cretaceous Research, 120, 104704, doi.org/10.1016/j.cretres.2020.104704.

The Mesozoic era (~252—66 Ma) is traditionally considered as a prolonged greenhouse period, witnessing the breakup of the Pangaean supercontinent. Orbital cycles have, for example, been invoked as drivers of e.g. Pangaean „Megamonsoon“ variability and eustatic sea level cycles in the Mesozoic.We aim to contribute to a more comprehensive understanding of orbital effects on Mesozoic climates by employing the newly developed CLIMBER-X Earth System Model. Here, we primarily use its coupled atmosphere, ocean, sea ice and vegetation modules, but also include preliminary tests with dynamic carbon cycle and ice-sheets. We present first results from a set of transient climate simulations of four Mesozoic timeslices representative for Triassic, Jurassic, Early Cretaceous and Late Cretaceous boundary conditions (e.g. paleogeography and solar luminosity). The simulations each cover ~100,000 years and are driven by changing precession, obliquity, and eccentricity.We would like to use the opportunity to discuss this approach and associated questions with the community. For example: Would changing paleogeography and climate background state have modified the response to orbital forcings? Could eustatic sea level cycles have been caused by orbitally-driven redistribution of water between the ocean and land water storages or should orbitally-forced ice sheets also have played a role in the alleged Mesozoic greenhouse? Which connections can be established to proxy records?

The Mesozoic Era (~252-66 Ma) is a decisive period in Earth’s history. It is marked by a tectonic transition from the Pangea supercontinent towards a modern continental configuration as well as the ecological success of the dinosaurs and the evolution of mammals, flowering plants, stony corals and important groups of planktic calcifiers. The Mesozoic is generally considered as a greenhouse climate period, with especially high global temperatures during the Triassic and the Late Cretaceous. Here, we present novel modeling results on the evolution of global climatic conditions through the Mesozoic.An ensemble of equilibrium climate states for 40 geological timeslices between 255 and 60 Ma is simulated with the CLIMBER-3α Earth System Model of Intermediate Complexity. The influence of changing paleogeography, sea level, vegetation cover, solar luminosity, orbital configuration and atmospheric CO2 concentration is systematically tested based on constraints from published geological proxy reconstructions and previous modeling work.Atmospheric pCO2 is found to be the strongest driver of global mean temperatures, which are generally elevated above the present and reach ≥20°C in the Late Triassic to Early Jurassic and the mid-Cretaceous if a recently published pCO2 proxy compilation is employed. The simulated seasonal latitudinal shift of high precipitation zones exhibits a maximum during the mid-Triassic to Early Jurassic and therefore supports the notion of a “Megamonsoon” during this time. Simulated humid and arid climate zones generally agree well with spatial distributions of geologic climate indicators like coal and evaporites, although some discrepancies exist. The same applies to the correlation of fossil stony coral reef distributions with regions where seawater temperatures would have been suitable for (modern) coral reefs. We will discuss which changes of Earth System parameters throughout the Mesozoic can best explain shifts in these distributions.

The genus Praecypridea gen. nov. (Cypridoidea, Family Cyprideidae Martin, 1940) is described and thus far comprises four species: the type species Praecypridea acuticyatha (Schudack, 1998) comb. nov., Praecypridea postelongata (Oertli, 1957) comb. nov., Praecypridea suprajurassica (Mojon, Haddoumi & Charriére, 2009) comb. nov. and Praecypridea acuta (Moos, 1959 in Wicher, 1959) comb. nov. Representatives of the new genus have been described from the Middle to Late Jurassic of Europe, North America and Africa and the Early Cretaceous of South America, with other presumed representatives also occurring in the Early Cretaceous. Species of Praecypridea are considered to represent members of the ancestral lineage of the extinct genus Cypridea Bosquet, representatives of which flourished in non-marine habitats of latest Jurassic to Early Cretaceous age and account for the first period of abundance of the non-marine Cypridoidea.