Abstract Early Jurassic plesiosaurian fossils are rare in the Scandinavian region, with a few isolated bones and teeth known from Bornholm, and anecdotal finds from East Greenland. The only other identifiable specimens derive from Toarcian-aged (based on ammonites) erratics deposited during Late Pleistocene glacial advances near the town of Ahrensburg, NE of Hamburg in northern Germany. The geographical source of these transported clasts is debated, but reconstructed ice-flow directions and lithofacies comparisons implicate either the offshore Baltic Sea between the Island of Bornholm and Mecklenburg–Vorpommern (Germany) or, less probably, south of the Danish Archipelago (Mecklenburg Bay). These regions collectively bordered the Fennoscandian landmass and adjacent Ringkøbing-Fyn Island in the late Early Jurassic, and were dominated by near-shore marine deltaic to basinal settings. The Ahrensburg plesiosaurian remains include postcranial elements reminiscent of both the microcleidid Seeleyosaurus and the rhomaelosaurid Meyerasaurus . These occur alongside other classic ‘Germanic province’ marine amniotes, such as the teleosaurid crocodyliform Steneosaurus and ichthyosaurian Stenopterygius cf. quadriscissus : thus, advocating faunal continuity between Scandinavia and southern Germany during the Toarcian, and a less pronounced marine reptile faunal provinciality than previously assumed.

Abstract We report new ichthyosaur material excavated in lower Toarcian levels of the LafargeHolcim Val d'Azergues quarry in Beaujolais, SE France. A partially articulated skull and a smaller, unprepared but likely subcomplete skeleton preserved in a carbonate concretion are identified as stenopterygiids, a family of wide European distribution during the Early Jurassic. These specimens are among the finest preserved Toarcian exemplars known from Europe and, in one of them, soft tissue preservation is suspected. Their state of preservation is attributed to the combination of prolonged anoxic conditions near the water–sediment interface and early carbonate cementation resulting from the activity of sulfate-reducing bacteria. We also present carbon and strontium isotope values obtained from the study site that allow detailed temporal comparisons with other Toarcian vertebrate-yielding sites and environmental perturbations associated with the Toarcian Oceanic Anoxic Event (T-OAE). These comparisons suggest that the relatively high abundance and good preservation state of Toarcian vertebrates was favoured by a prolonged period of low bottom water oxygenation and accumulation rates. The environmental conditions that prevailed during the T-OAE were probably responsible for the extensive nature of Lagerstätte-type deposits with exceptional preservation of marine organisms. Testing whether the T-OAE had a biological impact on marine vertebrates requires a precise chemostratigraphic context of the fossil record spanning the Pliensbachian–Toarcian interval.

Abstract Basin-scale stratigraphic correlation is the fundamental base for successful reservoir exploration, and especially when dealing with cross-border areas. Differences in lithostratigraphic and chronostratigraphic nomenclature between sub-basins and countries often result in problematic estimations of reservoir geometries and potential. This study combines available biostratigraphic, biofaunal and lithofacies data, together with sequence-stratigraphical correlations of the Lower Jurassic from the Central European Basin (CEB), to propose a genetic-based framework of transgressive and regressive depositional units. The determination of four major biofacies environments, composed of (I) polyhaline open-marine/offshore environments, (II) upper mesohaline marine–brackish environments, (III) lower mesohaline brackish environments and (IV) low oligohaline to freshwater continental environments comprising very rare marine phytoplankton and terrestrial spores and pollens, were translated into 12 biofacies reconstructions of ammonite (sub-) chronozone levels. Variations of biofacies reconstructions in time and space were supplemented by biostratigraphically constrained large-scale progradational and retrogradational sedimentary architecture. Retrogradation is accompanied by increasing polyhaline environments and pinpoint basinwide third-order flooding events, whereas progradation is accompanied by decreasing polyhaline environments pointing to third-order regressions. The outcomes of this study support exploration of Lower Jurassic deep geothermal reservoirs or CO 2 storage sites in the eastern CEB (especially Germany and Poland). Supplementary material: A list of all documented Liassic ammonites known from the eastern European shelf area (Denmark, The Netherlands, Sweden, Germany, Poland; wells and outcrops) is available at https://doi.org/10.6084/m9.figshare.c.3923467