Grzegorz Pieńkowski

Analyses of coprolites provide important data on animal feeding and food quality, including information on the taxonomy of the biotope. Knowledge of the diet of extinct animals has implications for our understanding of the evolution of various physiological strategies and feeding adaptations. Here we provide the first description of plant remains preserved in coprolites from early Hettangian deposits at Sołtyków (Holy Cross Mountains, Poland). The coprolites probably originated from herbivorous sauropodomorphs, ornithischians and large carnivorous theropods, from which tracks are known from the site. Herbivorous coprolite producers fed on the flora growing on a fluvial plain, and the cuticles that remain in the coprolites originated from crowns of gymnospermous trees or shrubs. Coprolites assigned to large predators contained more diverse plant remains, although they also belonged to the gymnosperms. These were probably ingested together with the stomachs and intestines of prey animals and/or accidentally while drinking or feeding. The plant cuticles originated from seed ferns (including the newly proposedKomlopteris distinctivaBarbacka sp. nov.), cycadophytes, ginkgophytes and conifers. A fragment of a needle leaf,Aciphyllum triangulatumBarbacka & Górecki gen. et sp. nov., is very similar to the leaves ofPinus, and is the oldest example of such a leaf type in the fossil record. Most ingested plants came from beyond the immediate surroundings of today’s outcrop. Palynological analysis of the coprolites yielded 31 taxa of sporomorphs from the herbivore coprolites and 14 sporomorph taxa from the coprolites of predators. Cheirolepidiaceous pollen grains ofClassopollis torosusdominated the sporomorph assemblage.

The Jurassic System (199.6-145.5 Ma; Gradstein et al. 2004), the second of three systems constituting the Mesozoic era, was established in Central Europe about 200 years ago. It takes its name from the Jura Mountains of eastern France and northernmost Switzerland. The term ‘Jura Kalkstein’ was introduced by Alexander von Humboldt as early as 1799 to describe a series of carbonate shelf deposits exposed in the Jura mountains. Alexander Brongniart (1829) first used the term ‘Jurassique', while Leopold von Buch (1839) established a three-fold subdivision for the Jurassic (Lias, Dogger, Malm). This three-fold subdivision (which also uses the terms black Jura, brown Jura, white Jura) remained until recent times as three series (Lower, Middle, Upper Jurassic), although the respective boundaries have been grossly redefined. The immense wealth of fossils, particularly ammonites, in the Jurassic strata of Britain, France, Germany and Switzerland was an inspiration for the development of modern concepts of biostratigraphy, chronostratigraphy, correlation and palaeogeography. In a series of works, Alcide d'Orbigny (1842-51, 1852) distinguished stages of which seven are used today (although none of them has retained its original strati graphic range). Albert Oppel (1856-1858) developed a sequence of such divisions for the entire Jurassic System, crucially using the units in the sense of time divisions. During the nineteenth and twentieth centuries many additional stage names were proposed - more than 120 were listed by Arkell (1956). It is due to Arkell's influence that most of these have been abandoned and the table of current stages for the Jurassic (comprising 11 internationally accepted stages, grouped into three series) shows only two changes from that used by Arkell: separation of the Aalenian from the lower Bajocian was accepted by international agreement during the second Luxembourg Jurassic Colloquium in 1967, and the Tithonian was accepted as the Global Standard for the uppermost stage in preference to Portlandian and Volgian by vote of the Jurassic Subcommission (Morton 1974, 2005). As a result, the international hierarchical subdivision of the Jurassic System into series and stages has been stable for many years.

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).

Soils – constituting the largest terrestrial carbon pool - are vulnerable to climatic warming. Currently existing uncertainties regarding carbon fluxes within terrestrial systems can be addressed by studies of past carbon cycle dynamics and related climate change recorded in sedimentary successions. Here we show an example from the Early Jurassic (early Toarcian, c. 183 mya) marginal-marine strata from Poland, tracking the hinterland response to climatic changes through a super-greenhouse event. In contrast to anoxia-related enhanced carbon storage in coeval open marine environments, Total Organic Carbon (TOC) concentrations in the Polish successions are substantially reduced during this event. Increasing temperature favoured fungal-mediated decomposition of plant litter – specifically of normally resistant woody tissues. The associated injection of oxidized organic matter into the atmosphere corresponds to abrupt changes in standing vegetation and may have contributed significantly to the amplified greenhouse climate on Earth. The characteristic Toarcian signature of multiple warm pulses coinciding with rapidly decreasing carbon isotope ratios may in part be the result of a radical reduction of the terrestrial carbon pool as a response to climate change.

Hettangian tetrapod burrows from the continental Steierdorf Formation at Anina, western Romania