First pterosaur remains from the Cretaceous of Poland

The first records of pterosaurs from the Cretaceous of Poland are reported, on the basis of fragmentary remains from the marine Upper Albian (Lower Cretaceous) of the Annopol Anticline, central Poland. The new material consists of four bone fragments, tentatively interpreted as: 1) a portion of wing phalanx; 2) a medial element of fused skull bones (parietal crest?); 3) a fragmentary carpal or tarsal; and 4) a distal phalanx of the pes (or a very small fragment of a long cervical vertebra). Previously, only the remains of marine vertebrates have been reported from the Cretaceous of the Annopol area. The pterosaur fossils studied most probably belonged to individuals that died while over the sea. The possibility that they represent remains dropped from floating carcasses, introduced into the marine environment by rivers, is regarded as less probable, as there are no remains of dinosaurs or other terrestrial fauna in the Annopol deposits

Large predatory marine reptiles from the Albian–Cenomanian of Annopol, Poland

During the Early–Late Cretaceous transition, marine ecosystems in Eurasia hosted a diverse set of large predatory reptiles that occupied various niches. However, most of our current knowledge of these animals is restricted to a small number of bonebed-like deposits. Little is known of the geographical and temporal extent of such associations. The middle Albian – middle Cenomanian phosphorite-bearing succession exposed at Annopol, Poland produces numerous ichthyosaurian and plesiosaurian fossils. These are mostly isolated skeletal elements (e.g. teeth, vertebrae), but disarticulated partial skeletons and an articulated, sub vertically embedded ichthyosaur skull are also available. The following taxa are identified: ‘Platypterygius’ sp., cf. Ophthalmosaurinae, Ichthyosauria indet., Polyptychodon interruptus, Pliosauridae indet., Elasmosauridae<indet. and Plesiosauria indet. The large-sized ichthyosaur ‘Platypterygius’ and the pliosaurid Polyptychodon interruptus predominate within the upper Albian – middle Cenomanian deposits. The Annopol record, combined with data from England, France and western Russia, suggests that ‘Platypterygius’ and Polyptychodon interruptus formed a long-term, stable ecological sympatry in marine ecosystems of the European archipelago, at least during the Albian – middle Cenomanian. In addition, the marine reptile assemblage from Annopol is distinct from other Eurasian ecosystems in containing also elasmosaurids in its Albian portion

Stratigraphy of the Albian-Cenomanian (Cretaceous) phosphorite interval in central Poland: a reappraisal

Several closely-spaced phosphorite beds stand out at the Albian–Cenomanian transition in the mid-Cretaceous transgressive succession at the northeastern margin of the Holy Cross Mountains, central Poland. They form a distinctive condensed interval of considerable stratigraphical, palaeontological, and economic value. Here, we correlate the classical section at Annopol with a recently investigated section at Chałupki. We propose a new stratigraphic interpretation of the phosphorite interval, based on lithological correlations, Rare Earth Elements and Yttrium (REE+Y) signatures of phosphorites, age-diagnostic macrofossils, and sequence stratigraphic patterns. This interval has long been considered as exclusively Albian in age. However, new macrofossil data allow us to assign the higher phosphorite levels at Annopol and Chałupki, which were the primary target for the phosphate mining, to the lower Cenomanian. In terms of sequence stratigraphy, the phosphorite interval encompasses the depositional sequence DS Al 8 and the Lowstand System Tract of the successive DS Al/Ce 1 sequence. The proposed correlation suggests that lowstand reworking during the Albian–Cenomanian boundary interval played an important role in concentrating the phosphatic clasts and nodules to exploitable stratiform accumulations. Our conclusions are pertinent to regional studies, assessments of natural resources (in view of the recent interest in REE content of the phosphorites), and dating of the fossil assemblages preserved in the phosphorite interval. On a broader scale, they add to our understanding of the formation of stratiform phosphorite deposits

From pristine aragonite to blocky calcite: Exceptional preservation and diagenesis of cephalopod nacre in porous Cretaceous limestones.

Aragonite (along with calcite) is one of the most common polymorphs of the crystalline calcium carbonate that forms the skeletal structures of organisms, but it has relatively low preservation potential. Under ambient conditions and in the presence of water, aragonite transforms into calcite, the stable polymorph. Aragonite is also more soluble therefore, in water-permeable siliceous limestones (opokas) that are typical of Upper Cretaceous deposits of Poland and Ukraine, the primary aragonitic skeletons are either entirely dissolved and found as moulds and casts or transformed into secondary calcite, whereas the primary calcitic shells remain well preserved. Contrary to the common notion of the lack of aragonite in such porous carbonate deposits, we show that relics of aragonite can be preserved as a nacreous lining on cephalopod moulds or as thin, lenticular structures entrapped in neomorphic calcite. Based on the observed intermediate steps of aragonite alteration, we propose an extended model of nacre diagenesis. Among the originally aragonitic biota, only nautilids and ammonites have retained relics of pristine skeletons. Such selective preservation of only some aragonitic structures (nacre but not the prismatic aragonitic layers) points to the role of microstructural and biochemical differences between cephalopod shell layers that may set a threshold for the dissolution, dissolution/precipitation or preservation of original biomineral structures

Late Maastrichtian cephalopods, dinoflagellate cysts and foraminifera from the Cretaceous-Paleogene succession at Lechówka, southeast Poland : Stratigraphic and environmental implications

The Lechówka section comprises the most complete Cretaceous-Paleogene (K-Pg) boundary succession in Poland and is among 29 sites worldwide with the youngest ammonite record. Here, cephalopods (ammonites and nautilids), organic-walled dinoflagellates (dinocysts) and foraminifera from the uppermost Maastrichtian interval are studied. In terms of ammonite biostratigraphy, the upper Maastrichtian Hoploscaphites constrictus crassus Zone is documented up to a level 120 cm below the K-Pg boundary. There is no direct, ammonite-based evidence of the highest Maastrichtian H. constrictus johnjagti Zone. However, the predominance of the dinocyst marker taxon Palynodinium grallator suggests the presence of the equivalent of the uppermost Maastrichtian Thalassiphora pelagica Subzone, which is correlatable with the H. c. johnjagti ammonite Zone. The planktonic foraminiferal assemblage is coeval with that from the H. c. johnjagti Zone as well. These data indicate that the top of the Maastrichtian at Lechówka is complete within the limits of biostratigraphic resolution, albeit slightly condensed. The dinocyst and foraminiferal assemblages are dominated by taxa that are characteristic of high-energy, marginal marine environments. A reduction in test size among the calcareous epifaunal benthic foraminifera is observed at a level 50 cm below the K-Pg boundary, which is possibly related to environmental stress associated with Deccan volcanism

Late Maastrichtian cephalopods, dinoflagellate cysts and foraminifera from the Cretaceous-Paleogene succession at Lechowka, southeast Poland: Stratigraphic and environmental implications

© 2015 Elsevier Ltd. The Lechówka section comprises the most complete Cretaceous-Paleogene (K-Pg) boundary succession in Poland and is among 29 sites worldwide with the youngest ammonite record. Here, cephalopods (ammonites and nautilids), organic-walled dinoflagellates (dinocysts) and foraminifera from the uppermost Maastrichtian interval are studied. In terms of ammonite biostratigraphy, the upper Maastrichtian Hoploscaphites constrictus crassus Zone is documented up to a level 120 cm below the K-Pg boundary. There is no direct, ammonite-based evidence of the highest Maastrichtian H. constrictus johnjagti Zone. However, the predominance of the dinocyst marker taxon Palynodinium grallator suggests the presence of the equivalent of the uppermost Maastrichtian Thalassiphora pelagica Subzone, which is correlatable with the H. c. johnjagti ammonite Zone. The planktonic foraminiferal assemblage is coeval with that from the H. c. johnjagti Zone as well. These data indicate that the top of the Maastrichtian at Lechówka is complete within the limits of biostratigraphic resolution, albeit slightly condensed. The dinocyst and foraminiferal assemblages are dominated by taxa that are characteristic of high-energy, marginal marine environments. A reduction in test size among the calcareous epifaunal benthic foraminifera is observed at a level 50 cm below the K-Pg boundary, which is possibly related to environmental stress associated with Deccan volcanism.publisher: Elsevier articletitle: Late Maastrichtian cephalopods, dinoflagellate cysts and foraminifera from the Cretaceous–Paleogene succession at Lechówka, southeast Poland: Stratigraphic and environmental implications journaltitle: Cretaceous Research articlelink: http://dx.doi.org/10.1016/j.cretres.2015.08.012 content_type: article copyright: Copyright © 2015 Elsevier Ltd. All rights reserved.status: publishe

Late Maastrichtian cephalopods, dinoflagellate cysts and foraminifera from the Cretaceous-Paleogene succession at Lechówka, southeast Poland : Stratigraphic and environmental implications

The Lechówka section comprises the most complete Cretaceous-Paleogene (K-Pg) boundary succession in Poland and is among 29 sites worldwide with the youngest ammonite record. Here, cephalopods (ammonites and nautilids), organic-walled dinoflagellates (dinocysts) and foraminifera from the uppermost Maastrichtian interval are studied. In terms of ammonite biostratigraphy, the upper Maastrichtian Hoploscaphites constrictus crassus Zone is documented up to a level 120 cm below the K-Pg boundary. There is no direct, ammonite-based evidence of the highest Maastrichtian H. constrictus johnjagti Zone. However, the predominance of the dinocyst marker taxon Palynodinium grallator suggests the presence of the equivalent of the uppermost Maastrichtian Thalassiphora pelagica Subzone, which is correlatable with the H. c. johnjagti ammonite Zone. The planktonic foraminiferal assemblage is coeval with that from the H. c. johnjagti Zone as well. These data indicate that the top of the Maastrichtian at Lechówka is complete within the limits of biostratigraphic resolution, albeit slightly condensed. The dinocyst and foraminiferal assemblages are dominated by taxa that are characteristic of high-energy, marginal marine environments. A reduction in test size among the calcareous epifaunal benthic foraminifera is observed at a level 50 cm below the K-Pg boundary, which is possibly related to environmental stress associated with Deccan volcanism

Relationship between Serum Lipids and Angiotensin Converting Enzyme Activity in Cholesterol-fed Rabbits

Wstęp: Zahamowanie układu renina-angiotensyna zmniejsza rozwój ogniska miażdżycowego w różnych doświadczalnych modelach miażdżycy tętnic. W niektórych badaniach eksperymentalnych obserwowano poprawę parametrów gospodarki lipidowej po zastosowaniu inhibitorów enzymu konwertującego angiotensynę. Brak jest danych na temat powiązania metabolizmu lipidów z aktywnością układu renina-angiotensyna. Metody: Celem pracy było określenie aktywności układu renina-angiotensyna w doświadczalnej hipercholesterolemii oraz korelacji pomiędzy parametrami układu lipidowego i aktywnością enzymu konwertującego angiotensynę (ACE). Do badań wykorzystano 20 królików rasy nowozelandzkiej, samców, które podzielono na 2 równoliczne grupy: grupa kontrolna (K) otrzymywała paszę standardową, a grupa badana (B) otrzymywała paszę o 1-procentowej zawartości cholesterolu. Po 6 miesiącach we krwi oznaczono stężenie cholesterolu całkowitego, frakcji LDL, HDL, trójglicerydów, fosfolipidów oraz aktywność ACE. Wyniki: We wszystkich przypadkach analizowanych parametrów gospodarki lipidowej stężenie w grupie zwierząt skarmianych paszą bogatocholesterolową było znamiennie wyższe. Aktywność ACE w surowicy krwi badanych zwierząt była wyższa o 15% niż w grupie kontrolnej (p < 0,05). Zaobserwowaliśmy istotną korelację pomiędzy aktywnością ACE a stężeniem trójglicerydów (r = 0,67, p < 0,04) i cholesterolu frakcji HDL (r = -0,89, p < 0,001). Wnioski: Obserwowany w warunkach hipercholesterolemii wzrost aktywności ACE w surowicy krwi może być jednym z mechanizmów jej patogennego działania. Uzyskane w naszych badaniach wyniki sugerują związek między układem renina-angiotensyna a metabolizmem lipidów i jednocześnie wskazują, że wpływ inhibitorów ACE na parametry lipidowe może wynikać z zahamowania aktywności ACE w surowicy krwi.Background Blockade of renin-angiotensin system reduces the development of atherosclerotic plaque in different animal models. In some experimental studies improvement of lipids metabolism was also observed after treatment with ACE-inhibitors. There is still little known about the mechanism of ACE-inhibitors action on lipids metabolism in hypercholesterolemic animals. Methods The aim of the study was to assess the renin-angiotensin system activity in experimentally-induced hypercholesterolemia and the possible relationships between lipids parameters and ACE activity. Twenty male New-Zealand rabbits were divided into two groups with the following dietary conditions: standard diet (n = 10) and 1% cholesterol diet (n = 10). After six months of experiment the blood was collected for analysis of ACE activity and lipids. Total, LDL and HDL cholesterol, triglycerides, phospholipids and ACE activity was measured enzymatically. Results At the end of the experiment there were no correlations between ACE activity and serum lipids in normolipidemic group. When compared with the control group, in cholesterol-fed rabbits ACE activity was increased (p < 0.05). We observed a positive correlation between ACE activity and serum triglycerides (r = 0.6%, p < 0.04) and inverse correlation between ACE activity and HDL cholesterol (r = -0.89, p < 0.001) in hypercholesterolemic rabbits. There was no correlation between ACE activity and any other lipids parameters in this group. Conclusions We have shown that standard diet supplemented with 1% cholesterol leads to increased activation of ACE and that there is a correlation between this activity and triglycerides and HDL cholesterol metabolism. This may be in part responsible for the observed changes in lipids metabolism after ACE-inhibitors in hyperlipidemic animals and then be one of the antiatherosclerotic properties of ACE-inhibitors