16 research outputs found
Fossil flora of Middle Jurassic Grojec clays (southern Poland). Raciborski鈥檚 original material reinvestigated and supplemented. I. Sphenophytes
Sphenopsid remains from Grojec clays (Grojec, Por臋ba, Mir贸w) collected and described by Raciborski in 1894 are re-examined for the first time and supplemented by Raciborski鈥檚 unpublished material housed at the Jagiellonian University (Institute of Botany) and by Stur鈥檚 preliminarily described material stored at the Geological Survey of Austria.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 Some of the unpublished specimens stored at the Jagiellonian University (Institute of Botany) correspond to Raciborski鈥檚 description, but considering the poor preservation of the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
Palynological indicators of palaeoenvironmental perturbations in the Basque-Cantabrian Basin during the latest Cretaceous (Zumaia, northern Spain)
The latest Cretaceous palynological assemblages from the southern margin of the Basque-Cantabrian Basin (northern Spain, Zumaia) are dominated by black opaque equidimensional phytoclasts, black opaque blade shaped phytoclasts and translucent gold-orange to brown phytoclasts. Deep water dinoflagellate cysts Cannosphaeridium utinensis and Pterodinium spp. constitutes a part of the assemblages throughout the whole succession. This record and previous study suggest deposition of the Zumaia section in the marine bathyal conditions, in relative close proximity to the land. Palynofacies analyses yields increased abundance of Leiosphaeridia spp. and some changes in the palynomorph proportions just before the significant lithological change near the lower/upper Maastrichtian. This signal may either be primary and record an environmental change, or taphonomic. Nevertheless, environmental interpretation of the upper Maastrichtian palynological assemblage seems to be more consistent with the late Maastrichtian marine regression, and in consequence, a reduction of the distance from the nearby land. Such conditions may have caused transport of leiosphaerids from shallower water sites
European Jurassic floras: Statistics and palaeoenvironmental proxies
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
European Jurassic floras : statistics and palaeoenvironmental proxies
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
Potent, p53-independent induction of NOXA sensitizes MLL-rearranged B-cell acute lymphoblastic leukemia cells to venetoclax
The prognosis for B-cell precursor acute lymphoblastic leukemia patients with聽Mixed-Lineage Leukemia聽(MLL) gene rearrangements (MLLr BCP-ALL) is still extremely poor. Inhibition of anti-apoptotic protein BCL-2 with venetoclax emerged as a promising strategy for this subtype of BCP-ALL, however, lack of sufficient responses in preclinical models and the possibility of developing resistance exclude using venetoclax as monotherapy. Herein, we aimed to uncover potential mechanisms responsible for limited venetoclax activity in MLLr BCP-ALL and to identify drugs that could be used in combination therapy. Using RNA-seq, we observed that long-term exposure to venetoclax in vivo in a patient-derived xenograft model leads to downregulation of several tumor protein 53 (TP53)-related genes. Interestingly, auranofin, a thioredoxin reductase inhibitor, sensitized MLLr BCP-ALL to venetoclax in various in vitro and in vivo models, independently of the p53 pathway functionality. Synergistic activity of these drugs resulted from auranofin-mediated upregulation of NOXA pro-apoptotic protein and potent induction of apoptotic cell death. More specifically, we observed that auranofin orchestrates upregulation of the NOXA-encoding gene Phorbol-12-Myristate-13-Acetate-Induced Protein 1 (PMAIP1) associated with chromatin remodeling and increased transcriptional accessibility. Altogether, these results present an efficacious drug combination that could be considered for the treatment of MLLr BCP-ALL patients, including those with聽TP53聽mutations
Fossil flora of Middle Jurassic Grojec clays (southern Poland). Raciborski鈥檚 original material reinvestigated and supplemented. II. Pteridophyta. Osmundales
In the second part of the series dealing with the flora of the Grojec clays (Poland, Middle Jurassic), macroremains of Osmundales are introduced. The re-examined and supplemented material originates from three collections: specimens collected and described in Polish by Raciborski in 1894; specimens preliminarily described by Stur (1888), housed at the Geological Survey of Austria; and Raciborski鈥檚 still-unpublished material stored at the Institute of Botany of the Jagiellonian University. So far, 15 taxa of Cladophlebis have been described from the Osmundales of Grojec clays, and two species of Todites (Todea) and Osmundopsis (Osmunda) sturii. Detailed observations indicate that a large part of the material (12 taxa described by Raciborski) should be assigned to three widespread Jurassic species: Cladophlebis denticulata, C. haiburnensis, and C. roessertii. Cladophlebis aurita and C. bartonecii, created by Raciborski, should be retained. The occurrence of sterile and fertile fronds of Todites williamsonii (originally described as Todea williamsonis, Cladophlebis whitbiensis, and Cladophlebis solida) is confirmed for Grojec. Two species described by Raciborski (1894) required a change of generic names - Osmundopsis (Osmunda) sturii and Todites (Todea) princeps. This paper provides the taxonomical descriptions and considers the palaeoecology of 5 Cladophlebis species (C. aurita, C. denticulata, C. haiburnensis, C. roessertii, C. bartonecii) and other osmundaceous ferns such as Osmundopsis sturii, Todites williamsonii, and T. princeps
Changements macrofloristiques et microflorisiques dans les communaut茅s de plantes du Jurassique moyen du forage Cianowice 2 (Pologne m茅ridionale)
The flora of the Cianowice 2 borehole (c. 20 km NW of Cracow, Poland), dominated by cycadophytes (mainly bennettitaleans) and conifers, shows high taxonomic diversity relative to the low number of specimens. Twenty species were identified in the 96 determinable plant fragments found in 27 core samples: Cladophlebis sp. (ferns), Pachypteris rhomboidalis (Ettingshausen) Nathorst and Ptilozamites cycadea (Berger) M枚ller (seed ferns), Anomozamites nilssonii (Phillips) Seward, Nilssoniopteris solitaria (Phillips) Cleal & Rees, Otozamites mimetes Harris, Otozamites parallelus Phillips, Pterophyllum thomasii Harris, Pterophyllum cf. aequale (Brongniart) Nathorst, Ptilophyllum cf. okribense forma ratchiana Doludenko & Svanidze, Ptilophyllum pecten Phillips, Ptilophyllum sirkennethii Watson & Sincock, Cycadolepis sp. (bennettitaleans), Pseudotorellia grojecensis Reyman贸wna, Pseudotorellia samylinae Nosova & Kiritchkova, Pseudotorellia sp. (Gymnospermae incertae sedis), Bilsdalea dura Harris, Mirovia szaferi Reyman贸wna, and Brachyphyllum stemonium Kendall (conifers). The floristic composition is supplemented by palynological data. The taxa were connected to five depositional successions distinguished along the core: one, alluvial fans; two, four and five, meandering/anastomosing river depositional systems with fluvial plain deposits; and three, lacustrine/backswamp environment developed on fluvial plain. The composition of the fossil plant assemblage changes with the depositional setting within the same range of taxa, seen mainly in changed combinations of taxa, which are most diverse in the fluvial plain deposits. Some taxa occur in a single depositional succession; some are present in two or three. The sporomorph assemblages of particular depositional environments differ significantly from the composition of the co-occurring macroflora: ferns occur sporadically in the macroflora of each depositional environment but they strongly dominate the sporomorph assemblage. Our proposed reconstruction of the palaeoenvironment is a slight rise descending into a valley with a depositionary basin, with gymnosperms on the slope and ferns at the base. Some species are shared between Cianowice and nearby Middle Jurassic localities in Grojec and Zabierz贸w, and the majority of taxa are known from the Middle Jurassic, suggesting that the Cianowice deposits are of that age
Early Jurassic dinosaur-dominated track assemblages, floristic and environmental changes in the Holy Cross Mountains region, Poland
The Early Jurassic succession of the Holy Cross Mountains region in Poland offers a rare opportunity to study ecosystem complexity during the evolution and diversification of early dinosaurs, especially herbivorous ones. The section consists of continental and coastal deposits containing fossil assemblages spanning nearly 25 My of changes in terrestrial plants and some groups of invertebrates and tetrapods. Based on macrofossils and pollen and spores, the broader characteristics of the flora in this succession are presented. The floral assemblages show typical Early Jurassic characteristics and contain lycopsids, sphenopsids, ferns, cycadaleans, bennettitaleans, gnetaleans and ginkgoaleans, as well as conifers, and are similar to other Hettangian鈥揟oarcian floral successions in Europe, showing the presence of a vast coniferous forest dominated by Hirmeriella in the early Hettangian, replaced by ginkgophyte-dominated floras in younger stages and araucarian conifer-dominated forests in the late Pliensbachian. Dinosaurs are documented mainly from their trace fossils (tracks and coprolites). Six distinct track assemblages (stratigraphically separated ichnoassemblages) of different ages can be identified. Current evidence indicates that while Anomoepus tracks are abundant throughout the long Hettangian鈥搇ate Pliensbachian interval, medium-sized to large ornithischian tracks do not occur below the lower鈥搈iddle Hettangian transition zone, associated with the first major marine transgression in the region. Hettangian strata with different theropod tracks (Grallator, Anchisauripus, Eubrontes, Kayentapus, cf. Megalosauripus), small Anomoepus tracks, numerous medium-sized Anomoepus-like tracks, Moyenisauropus tracks, tetradactyl tracks of sauropodomorphs (cf. Pseudotetrasauropus) and oval-shaped tracks of sauropods (Parabrontopodus) significantly contrast with the higher part of the Lower Jurassic succession (upper Pliensbachian Drzewica Formation and middle鈥搖pper Toarcian Borucice Formation) containing new types of medium-sized to large theropod tracks (Therangospodus), small and medium-sized bird-like tridactyl tracks (cf. Trisauropodiscus, cf. Anomoepus), exceptionally large, oval-shaped sauropod tracks (Sauropoda indet.), and new types of medium-sized and large ornithischian tracks (cf. Deltapodus, cf. Anomoepus). This points to a noticeable difference between the Hettangian and late Pliensbachian鈥揟oarcian dinosaur ichnofaunas and may facilitate the study of regional and global changes and correlations. Both the palaeofloras and dinosaur trace fossils document ecosystem diversity and ecosystem changes, presented here in review form. The nature of these changes requires more detailed study, but preliminary results suggest the occurrence of rather complex and pronounced transformations in the dinosaur communities of the Holy Cross Mountains region. Based on our observations, the most significant event in Early Jurassic ecosystems took place within the Hettangian (change in floristic composition, the emergence of new groups of dinosaurs), but we also found what we believe to be a record of a major faunal turnover across the late Pliensbachian鈥搈iddle鈥搇ate Toarcian interval
Changes in terrestrial floras at the Triassic-Jurassic Boundary in Europe
One of the biggest mass extinctions took place at the Triassic-Jurassic Boundary. It affected both marine and terrestrial ecosystems, and caused the disappearance of many animal taxa, mostly marine ones. Its influence on floral changes has been widely discussed, with arguments offered for the sudden mass extinction of plants over vast areas, or, alternatively, for slow, less extensive changes. The aim of this study was to statistically verify changes in terrestrial plant composition during the TJB in Europe, and to examine the type and extent of these changes. Data from Polish localities, an interesting new addition to the floristic data from the TJB, were compared with those from other selected localities in Europe. The database contains 311 macroflora taxa from 106 localities (16 Polish) in 13 countries, grouped into 29 regions; and 571 microflora taxa from 105 localities (29 Polish) in 11 countries, grouped into 37 regions. The analysed data cover the period from the Anisian to the Toarcian stages. Range-based metrics for diversity dynamics were calculated to show trends in floral changes during the studied time interval, the focus being on the TJB. Due to strong disproportions in the number of localities and occurrences, the Rhaetian and the Hettangian stages were overrepresented. The warm and humid climate of those stages promoted plant diversity and led to the formation of numerous broad floodplains conducive to the preservation of remains (e.g. in coal). The patterns established by the raw data analyses were also assessed by applying a sampling standardisation procedure. Our results, based on accurate data from Poland and the rest of Europe, confirm and visualize a scenario in which there were no significant changes in terrestrial plant composition at the TJB. Hierarchical clustering suggests that local habitat conditions are the key factor in the grouping of localities with similar floristic composition, and that differences between floras are not associated with the time dimension (stages)