Amblypteridae are ray-finned fish particularly common in late Carboniferous and early Permian vertebrate assemblages. We describe a rich new fish assemblage from the Poland-Czechia borderland, composed of only one species of amblypterid: Paramblypterus rohani. The analysis of articulation and completeness of the individuals unearthed shows that most of them underwent two, strongly different taphonomic histories. The first is represented by highly articulated and complete specimens buried close to their death site. Their decomposition took place mainly at the bottom of a deep lake with low hypolimnic temperature and bottom hypoxia. The second is represented by highly disarticulated and incomplete specimens, for which the bloat and float mechanism appears to be the main driver of decomposition. The results obtained suggest that thermal conditions in the former reservoir were seasonally varying. Moreover, the mass occurrence of amblypterids in environments largely touched by hypoxia shows that they were efficient open-water predators, which contrasts with previous ecomorphological studies of this group. The stratigraphic position of the assemblage studied remains unclear due to conflicting biostratigraphic and field data. The most parsimonious resolution of this ambiguity comes through considering the occurrence of various amblypterid species in the Intra-Sudetic Basin as controlled by environmental factors rather than by evolution.
Corneous skin appendages are not only common and diverse in crown-group amniotes but also present in some modern amphibians. This raises the still unresolved question of whether the ability to form corneous skin appendages is an apomorphy of a common ancestor of amphibians and amniotes or evolved independently in both groups. So far, there is no palaeontological contribution to the issue owing to the lack of keratin soft tissue preservation in Palaeozoic anamniotes. New data are provided by a recently discovered ichnofossil specimen from the early Permian of Poland that shows monospecific tetrapod footprints associated with a partial scaly body impression. The traces can be unambiguously attributed to diadectids and are interpreted as the globally first evidence of horned scales in tetrapods close to the origin of amniotes. Taking hitherto little-noticed scaly skin impressions of lepospondyl stem amniotes from the early Permian of Germany into account, the possibility has to be considered that the evolutionary origin of epidermal scales deeply roots among anamniotes.
The Intrasudetic Basin represents one of the larger late- to post-Variscan intramontane troughs of Central Europe. It is situated at the northern margin of the Bohemian Massif. The Basin represents a fault-bounded synclinorial structure and was formed in the late Visean as a depression framed by tectonically active margins. During the Permian, the basin was filled with dominantly fine-grained alluvial to lacustrine deposits, accompanied by volcanic rocks. Volcanic activity evolved with time and comprised emplacement of subvolcanic intrusions, effusion of lava flows as well as deposition of widespread ignimbrites (Awdankiewicz, 1999). These volcano-sedimentary units are known as the Słupiec Formation in the Polish part and the Broumov Formation in the Czech part of the Intrasudetic Basin, respectively. So far, based on generally imprecise biostratigraphic evidence and regional correlations, the Słupiec Formation sedimentary rocks together with the intercalated volcanic rocks were (usually) assigned to the Sakmarian. However, preliminary results of U-Pb SHRIMP zircon dating of the Góry Suche Rhyolitic Tuffs and the Łomnica Rhyolites – a widespread ignimbrite sheet and associated rhyolitic laccoliths intercalated in the Słupiec/Broumov Formation - suggest that these volcanic rocks can be older than supposed by 5-10 My. Such age estimate would assign these ignimbrites and rhyolites to the Asselian, not Sakmarian.In this contribution the biostratigraphic evidence on the position of the Słupiec/Broumov Formation is re-assessed. The fluvio-lacustrine sedimentary members of these formations accumulated probably in semi-arid palaeoclimatic conditions with seasonally-controlled watertable.Numerous footprints of reptiles and amphibians, aquatic vertebrates: chondrichthyans, actinopterygians and amphibians, also palaeobotanical remains were preserved (e. g.  Jerzykiewicz, 1987; Zajíc, 2000; Stamberg & Zajíc, 2008; Voigt et al., 2012; Opluštil et al., 2016). Unfortunately, they appear only fairly suitable for detailed biostratigraphy as their successions may be environmentally-controlled, and most of them indicate a latest Carboniferous to early Permian age. At this level of knowledge, they are not suitable for detailed biostratigraphy, and thus comprehensive and comparative studies of the Late Carboniferous and Early Permian Central European volcanic-sedimentary basins are necessary to better constrain the stratigraphic position of the Słupiec/Broumov Formation of the Intrasudetic Basin.This research is funded by the Polish National Science Centre (Grant 017/26/M/ST10/00646).Awdankiewicz, M. (1999): Geologia Sudetica, 32 (1): 13-47; Jerzykiewicz, J. (1987): Palynology 11: 117-131; Opluštil, S., Schmitz, M., Kachlík, V. & Štamberg, S. (2016): Bulletin of Geosciences, 91: 399–432; Štamberg, S. & Zajíc, J. (2008): Carboniferous and Permian faunas and their occurrence in the limnic basins of the Czech Republic. Museum of Eastern Bohemia; Voigt, S., Niedźwiedzki, G., Raczyński, P., Mastalerz, K. & Ptaszyński, P. (2012): Palaeoclimatology, Palaeoecology, 313-314: 173-180; Zajíc, J. (2000): Courier-Forschungsinstitut Senckenberg, 223: 563-575. 
The geology of the Intrasudetic Basin (Poland and Czech Republic) in the past was studied separately in both countries. Our project combined data from both parts of the basin to study the development of the limnic basin during the seasonally extreme climate in the Early Permian. The Lower Rotliegend Słupiec Formation (Broumov Formation in the Czech part) red bed deposits appear the most promising for palaeoenvironmental and palaeoclimatic studies. Fine-grained weathering products  (black shales), tuff admixtures and autochthonous components (limestones) in lakes contain many remains of plants, and traces of activity of invertebrates and vertebrates including extraordinarily numerous traces fossils of tetrapods (reptiles and amphibians) (e.g., Voigt et al. 2012) and fish remains (e.g., Stamberg & Zajíc, 2008). The Słupiec Formation is interpreted as a successively finning-upwards megacyclothem consisting, from base to top, of alluvial fan, fluvial and lacustrine deposits (Wojewoda and Mastalerz, 1989; Kurowski, 2004). However, the cyclicity is also clearly marked by successive transitions from lacustrine sediments with preserved fish remains to terrestrial sediments with numerous tracks of terrestrial reptiles and amphibians. This seasonal climate with dominant monsoonal rainy summer and winter seasons with low precipitation is clearly recorded in deposits of alluvial-fluvial plains and lakes. Extreme weather conditions, such as possible night frosts, were also recorded in the sediments, although the basin was located relatively close to the equator.This research was funded by the Polish National Science Centre (Grant 017/26/M/ST10/00646).Kurowski, L. (2004); Geologia Sudetica, 36: 21–38; Štamberg, S. & Zajíc, J. (2008): Carboniferous and Permian faunas and their occurrence in the limnic basins of the Czech Republic. Museum of Eastern Bohemia; Voigt, S., Niedźwiedzki, G., Raczyński, P., Mastalerz, K. & Ptaszyński, P. (2012): Palaeogeography, Palaeoclimatology, Palaeoecology, 313-314: 173-180; Wojewoda, J. & Mastalerz, K. (1989): Przegląd Geologiczny, 37: 173–180.
Objective The aim of this cross-sectional in vitro study was to evaluate the mucosal surfaces of healthy maxillary sinuses, explore different forms of bacterial microorganism colonies present on the mucous membrane, and determine a mucosal surface area they occupy. Methods Samples of the maxillary sinus mucosa were collected from 30 healthy patients (M = 11; F = 19). The material was obtained during the Le Fort I osteotomy performed during corrective jaw surgery. The morphological and morphometric analysis of sinus mucosa and bacterial film that was grown on it was performed using scanning electron microscopy (SEM) as well as imaging software. Results Scanning electron microscopy analysis showed the presence of different bacterium and bacteria-like structures in all the analyzed samples. In most cases, the bacterial film was mostly composed of diplococci-like and streptococci-like structures on the mucosa of the paranasal sinus. In any case, the mucous layer did not cover the whole lining of the evaluated sample. Each colony consists of more than 20 single bacterial cells, which has grown in aggregates. Conclusions Under the conditions of normal homeostasis of the body, the maxillary sinuses present diverse bacterial colonization. The bacteria are dispersed or concentrated in single microcolonies of the biofilm on the border of the mucous covering the ciliary epithelium. There is no uniform layer of the biofilm covering the mucosa of the maxillary sinuses. Because the biofilm is detected on healthy individuals sinus mucosa, the clinical question if it may become pathogenic is unclear and require an explanation.
'/%3e%3cpath fill='%23fff' d='m8.751-17.959 10.11 11.373L3.997-9.844l13.94-6.1-7.692 13.129z'/%3e%3c/svg%3e)
