The transition from the late Permian to Early Triassic was associated with one of the biggest biotic crises in the entire Phanerozoic which affected life in both marine and continental settings. ...Unlike in the marine realm, the environmental dynamics in continental palaeoenvironments across the Permian-Triassic interval are still poorly understood. In order to fill this knowledge gap, we studied the Permo-Triassic continental succession from the SE part of the intracontinental Central European Basin (CEB). High-resolution sedimentological logging of over 1700 m of cores, supplemented by micromorphology of palaeosols, palynofacies, and quantitative spore-pollen analyses, allowed reconstructing major steps in palaeoenvironmental evolution, and assessing the magnitude of extrinsic factors responsible for such development. The studied interval is dominated by redbeds deposited in arid, semi-arid, and sub-humid subenvironments in which palaeosol profiles are important elements of facies architecture. Vertical and lateral facies arrangement indicate three major development stages associated with progradation of a large distributary fluvial system towards the centre of the basin. These stages correspond to the main lithostratigraphic units in the studied area. In the first stage, the saline mudflats were replaced by muddy floodplain facies and then by medial and proximal parts of the ephemeral fluvial system of the Podzamcze Formation. The overlying Siodła Formation represents the stage of environmental stabilisation associated with widespread pedogenesis resulting in the formation of thick cumulative palaeosol profiles. The last stage was marked by the influx of coarse-grained fluvial sediments of the Jaworzna Formation and change in soil character towards less evolved types in overbank facies of the Szczukowice Formation. The change in the sedimentary record and soil types reflects the successive humidification in the SE part of the CEB, supported by increasing contribution of the hygrophytic over mostly xerophytic palynomorphs in the upper Permian palynological assemblage. This humidification trend was likely an environmental response to global warming in the late Permian.
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•Evolution of distributary fluvial systems in the SE Central European Basin across the Permian/Triassic boundary•Climatic and tectonic influence on sedimentary and pedogenic record•Seasonal humidity driven by megamonsoon system from the Tethys•Increased humidity reflected by changes in palynomorph composition
We studied the upper Permian and Lower Triassic deposits from the northern and northwestern marginal part of the Holy Cross Mountains (SE part of the Central European Basin or CEB, Poland) to examine ...stratigraphic continuity between these two systems, and to revise the currently existing stratigraphic framework. A previously existing informal lithostratigraphic scheme has been revisited and placed in a broader chronostratigraphic and palaeoenvironmental context. Sedimentary continuity across the Permian–Triassic (P/T) boundary has been confirmed by the presence of Lueckisporites virkkiae Bc morphological norm and Lundbladispora obsoleta–Protohaploxypinus pantii palynomorphs. Facies development reflects an interplay between climatic variations and tectonism during late Permian – Early Triassic time. The P/T boundary was placed between the Siodła Formation and overlying Szczukowice and Jaworzna formations, which coincides with the classical Zechstein–Buntsandstein boundary in the SE part of the CEB. The facies changes recorded in the studied terrestrial succession of the P/T boundary shed light on the environmental dynamic prior, during and after one of the biggest biotic crises in Earth’s history.
The dry climate that prevailed during the Triassic period in the eastern part of the Central European Basin was interrupted by several humid episodes of varying durations. One of them was the Carnian ...Pluvial Episode (CPE), which took place in the late Julian (early Carnian age) and is confined to Camerosporites secatus and Aulisporites astigmosus palynological zones. CPE is marked by a significant change in the qualitative and quantitative composition of spore-pollen assemblages from mostly xerophytic species preserved in the upper part of the Grabfeld Formation (“Lower Gipskeuper”) to hygrophytic forms, which dominate in the Stuttgart Formation (“Schilfsandstein”). Changes in climate towards more humid conditions have been documented palynologically and sedimentologically, and analyzed utilizing quantitative spore-pollen analysis and Principal Component Analysis (PCA) of miospores occurring in core material from Poland. In all the studied boreholes, a shift from dry to wet climate is observed at the boundary between the Grabfeld Formation and the Stuttgart Formation, which matches the data from other European regions.
The Triassic is an exceptionally interesting period from the point of view of conifer evolution. The oldest representatives of some modern families appear in the fossil record in the Upper Triassic ...and all recent conifer families probably originated during this time. The stages whereby the primitive Voltziales transformed into the evolutionarily advanced families of modern conifers in the Triassic are yet to be fully documented. A newly discovered Upper Triassic (Norian) locality in Patoka (SW Poland, Upper Silesia) with a unique fossil record offers us a rare opportunity to fill this gap. In this paper, we describe the very well preserved remains of a new conifer from this locality. We have been able to reconstruct the whole plant and propose a new taxon, Patokaea silesiaca gen. et sp. nov., on the basis of organic attachment and similar cuticular details on leaves, ovuliferous cones, seed scale-bract complexes, ovules and mature seeds as well as polliniferous cones containing pollen grains of the Enzonalasporites type in situ. This plant combines shoots bearing Brachyphyllum-Pagiophyllum-type leaves with a new type of seed scale-bract complex clearly derived from evolutionary advanced Voltziales and polliniferous cones somewhat similar to the Cheirolepidiaceae (Classostrobus) type. Based on this distinctive and hitherto unique combination of features, a new conifer family – Patokaeaceae – has been proposed. The ovuliferous cones of this conifer are lax and borne singly at the end of leafy twigs. Ovule-bearing scales are stalked and trilobate with two lateral oval lobes, each bearing one ovule, and one sterile reduced lobe between them, all in one plane. The bract is small and leaf-like. Polliniferous cones are simple with helically arranged microsporophylls. Five to seven pollen sacs are arranged around the microsporophyll stalk. Polliniferous cones are borne singly at the end of leafy twigs. This is also the first evidence of a relationship between Enzonalasporites pollen and the parent plant. The pollen occurs in the polliniferous cones, in the micropyle inside the ovule and in the micropylar region inside the seed of this new conifer. This plant expands our view of voltzialean conifer diversity at the roots of modern conifer families.
•A new conifer from the Triassic of Poland, Patokaea silesiaca is described.•The plant combines Brachyphyllum/Pagiophyllum shoots with a new type of cone scale.•A new type of male cone with Enzonalasporites pollen in situ is described.•This is the first evidence of Enzonalasporites relationships.•This plant offers new clues to the evolution of voltzialean conifers.
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