Grzegorz Pacyna

Plant remains from the Polish Triassic. Present knowledge and future prospects

ABSTRACT The Triassic plant macrofossils of Poland are very poorly known. There are few Triassic rock exposures here, they contain very few plant specimens, there is little scientific interest in the subject, and the rare plant remains found in drill cores are of low stratigraphical significance. The Lower Triassic macroflora is surprisingly poorer taxonomically than coeval European floras, and only single specimens have been found. The flora of the Middle Triassic is even poorer as a result of the Muschelkalk sea transgression. Only the Upper Triassic floras contain many specimens and taxa. The Upper Triassic macrofloras from Polish territory are well known since the early 19th century. Pioneering descriptions of these floras were given by Goeppert and Raciborski. From the Polish Triassic, the seed fern Lepidopteris ottonis (index species for the Rhaetian stage) and Neocalamites lehmannianus (sphenopsid species typical of almost all European Upper Triassic and Lower Jurassic floras) were described for the first time ever. In the 20th century only single specimens were described from outcrops and drill cores. Barbacka revised Lepidopteris ottonis specimens from old collections and described some new material. Palynological research on Triassic strata in Poland intensified from the 1970s on. That work has produced spore-pollen and megaspore zonations for Triassic strata in Poland, but the correlation of the dispersed spores and pollen grains with their parent plants is low. The Polish Triassic flora is comprised of ferns, lycopsids, sphenopsids, cycads, bennettitaleans, ginkgoaleans and conifers. This flora is taxonomically poorer than equally old and geographically close European floras. All available data about Polish Triassic plants fossils are critically summarised in this paper for the first time. The biostratigraphical and lithostratigraphical correlations of Polish Triassic floras with other European Triassic floras are outlined. New macrofloral assemblages for the Lower and Middle Triassic and macrofloral assemblage zones for the Upper Triassic are proposed for Poland. Recent new finds of taxonomically rich, abundant and well-preserved floras accompanying vertebrate remains in Silesia provide an opportunity for comprehensive research on Polish Triassic floras. This should improve our perception of their taxonomy and allow them to be described in evolutionary and palaeoecological contexts

Critical review of research on the Lower Jurassic flora of Poland

ABSTRACT The Lower Jurassic plant macrofossils of Poland are poorly known. Relatively rich sources of fossils are found in only a few outcrops in the Holy Cross Mountains. Other described plant remains come from drill cores taken from most areas of Poland, but as a rule these are single specimens. The only professional descriptions of Lower Jurassic macroflora are papers by Raciborski, Makarewiczówna, and a team of researchers consisting of Reymanówna, Barbacka, Ziaja, and Wcisło-Luraniec. Raciborski’s fossil collection is still available for research and revision. Such work is in progress. The collection described by Makarewiczówna contained many interesting specimens but unfortunately the majority of them are now missing. Stratigraphic research by geologists has provided some new specimens from drill cores and outcrops in the Holy Cross Mountains but these have not been subjected to detailed palaeobotanical analysis. The palynology of the Lower Jurassic was focused on biostratigraphy from the outset of that research. As an outcome it provided spore-pollen and megaspore zonations for Lower Jurassic strata in Poland. The Polish Lower Jurassic flora is comprised of ferns (very numerous), lycopsids, sphenopsids, cycadaleans, bennettitaleans, gnetaleans, ginkgoaleans, and conifers. This flora is taxonomically poorer than the equally old and geographically close floras of Denmark, Sweden, and Germany. Macrofloristic data have been used by geologists as an important source of information for assessing the age of Lower Jurassic formations, particularly in the Holy Cross Mountains. Hence the need for the old collections to be taxonomically revised and for new material from outcrops and drill cores to be examined and described.

European Jurassic floras: statistics and palaeoenvironmental proxies

Abstract The Jurassic floras of Europe show considerable diversity. To examine the extent of this diversity and its possible causes we used multivariate statistical methods (cluster analysis, PCA, NMDS) to compare all significant Jurassic floras in Europe. Data were based on 770 taxa from 46 fossiliferous occurrences (25 units) from France, Germany, Greenland, Hungary, Italy, Norway, Poland, Romania, Scotland, Serbia, Sweden, Switzerland, and the United Kingdom. Statistical analyses were applied at species level and genus level, and also performed for the major plant groups. The genus cladograms show affinities between different localities based on environmental factors, while the cladograms based on species affinities indicate only taxonomical correlations. The study shows that locality age does not seem to be of paramount importance for floral composition.

Relationships between ecosystems and plant assemblages as responses to environmental conditions in the Lower Jurassic of Hungary and Romania

Abstract Two Early Jurassic localities, the Mecsek Mts in Hungary and Anina in Romania, are similarly significant and both floras are of autochthonous/paraautochthonous origin. In the Early Jurassic the Hungarian locality was a delta plain; the Romanian locality was an intramontane depression filled predominantly by a braided river system. The floristic composition of the two localities (52 genera, 120 species), although superficially similar (25 common genera), differs at species level (only 9 common species) as well as in the proportions of taxa in major plant groups. These differences can be explained by differences in environmental conditions resulting from palaeogeographic and topographic factors. Based on previous and recent studies, alpha diversity as well as statistically (DCA, PCA) differentiated ecogroups are compared and discussed. For common species, the GLM method was used to classify them to particular environmental response types. Their environmental requirements in both ecosystems are evaluated. Some of the shared species showed different preferences at the localities, explainable by their broad ecological tolerance.

Fossil flora of Middle Jurassic Grojec clays (southern Poland). Raciborski's original material reinvestigated and supplemented. I. Sphenophytes

Abstract Sphenopsid remains from Grojec clays (Grojec, Poręba, Mirów) collected and described by Raciborski in 1894 are re-examined for the first time and supplemented by Raciborski’s unpublished material housed at the Jagiellonian University (Institute of Botany) and by Stur’s preliminarily described material stored at the Geological Survey of Austria. Three species of Equisetum created by Raciborski (Equisetum renaulti, E. remotum, E. blandum) are now attributed to the common Jurassic species Equisetites lateralis, and the earlierundescribed Equisetites cf. columnaris is recognised. The occurrence of Neocalamites lehmannianus (originally described by Raciborski as Schizoneura hoerensis) has been confirmed from Grojec. The material that Raciborski referred to this species seems to be heterogeneous, and some specimens are now removed to the new proposed species Neocalamites grojecensis Jarzynka et Pacyna sp. nov. The new species is diagnosed by the following features: only a few prominent ribs present on shoot, leaf scars relatively large and ellipsoidal, numerous free leaves, vascular bundles alternate at node. Possibly the new species derives from Neocalamites lehmannianus or at least is closely related to it. Part of the poorly preserved remains can be determined only as Neocalamites sp. Another species created by Raciborski, Phyllotheca (?) leptoderma, is based on poorly preserved type specimens. Some of the unpublished specimens stored at the Jagiellonian University (Institute of Botany) correspond to Raciborski’s description, but considering the poor preservation of the original material and the not very realistic published illustrations of this species, they rather should be regarded as indeterminate cortical fragments of Neocalamites lehmannianus and/or badly preserved external cortical surfaces of the new species Neocalamites grojecensis. Phyllotheca (?) leptoderma should be considered a nomen dubium.