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Number of results: 12
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Abstract

Septal neck-siphuncular complex has been redescribed In Triassic (Carnian) Stolleyites tenuis (Stolley). Ammonites whose septal necks change orientation from retrochoanitic through intermediate to prochoanitic may be divided into two categories: dorsoprogressive and ventroprogressive. In the former category, the initial changes in the direction of septal necks orientation occur dorsally; in the latter, the ventral side exhibits more progressive changes. Among forms with siphuncular complex adjacent to the ventral wall, i.e., without a septum between the neck and ventral wall in the medial plane, the changes towards prochoanitic septal neck may begin in the ventrolateral part. The circumsiphonal invagination in those forms did not include the ventral part and their proper interpretation cannot rely on the medial plane only. Primary lamination and primary fibrous structure of the siphuncular tube had been described, as well as the microstructure of the distal tip of cuff and auxiliary deposit.

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Cyprian Kulicki
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Abstract

Prolacerta broomi is one of the most important of fossil reptiles. First considered as one of the earliest members of squamates, this basal archosauromorph has been used as a model for diapsid morphological evolution ever since its dis- covery, playing a pivotal role in hypotheses on the origin of diapsid reptiles. The holotype of Prolacerta broomi (UCMZ 2003.41R) is known from a mostly complete skull, but the original description is limited to the superficial features of the skull roof and palate. Since then, many other specimens of Prolacerta broomi have been recovered that potentially account for this limited access to anatomical information, but it remains unclear whether these aspects correspond well to the known material of the holotype. Here, the skull morphology of the holotype of Prolacerta broomi is revisited through the use of μCT scans. The identifications of some cranial elements have been corrected, such as the left prefrontal and lacrimal, and several new elements are revealed, including the epi- and ectopterygoids, prearticular, coronoid, and braincase bones. The orbitonasal region is described in detail and significantly shows a contribution of the lacrimal to the dorsal alveolar canal. Finally, the addition of the holotype as an independent OTU in recently published analyses indicate conflicts with the current knowledge on Prolacerta broomi phylogenetic affinity and taxonomy. First, it points to potential taxonomic inconsistency since the holotype does not form a monophyletic group with other Prolacerta broomi OTUs in any of the analyses and, second, it suggests a more basal position for the holotype than that recovered in some studies, more basal than rhynchosaurs and close to the origin of Crocopoda. Together, these findings indicate areas of future research interest in the study of early evolving archosauromorphs.
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Authors and Affiliations

Gabriela Sobral
1
ORCID: ORCID

  1. Staatliches Muse-um für Naturkunde Stuttgart, Rosenstein 1, 70191 Stuttgart, Germany
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Abstract

The long-ranging Early to Middle Triassic coniform conodont form-genus Cornudina Hirschmann occurs

abundantly in the Anisian of NW Turkey, Northern Tethys. Although suggested to represent the P1 element

of an apparatus of the Order Ozarkodinida Dzik, questions concerning the apparatus of Cornudina remain.

A description of the probable phylogenetic trends in the P1 elements of Cornudina is attempted and the role

of the form-genera Ketinella Gedik and Kamuellerella Gedik, as the alternative ramiform skeletal elements in

the Cornudina multi-element apparatus, is investigated. The newly described, Gedikella quadrata gen. nov.,

sp. nov., is an S element, Kamuellerella rectangularis sp. nov., is either an S3 or an S4 element, and Ketinella

goermueshi sp. nov., is an M element.

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Authors and Affiliations

Ali Murat Kılıç
Pablo Plasencia
Fuat Önder
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Abstract

The Polish basis of dolomites is remarkable. Their total reserves reported in the 62 deposits listed in current data bases of mineral resources amount to 1,500,000 t. However, there is a shortage of the so-called converter dolomites of high quality applicable in manufacturing of refractory materials. Such dolomites of the Triassic age have been quarried for many years in the Brudzowice and Ząbkowice Śląskie I deposits in the Silesian-Cracow region. The Libiąż deposit is perspective of this area, considering the character and properties of its dolomites. The dolomites of the Nowa Wioska and Stare Gliny deposits belong into the same group although their applying as refractories seems to be disputable at the moment and would require more detailed analyses of the chemical composition and firing properties of the rocks mentioned. The reason is that the dolomites of these deposits have been reported andmassively quarried up to now mainly for civil engineering (roads, buildings, etc.). Unfortunately, worsening properties of the dolomites occurring in Żelatowa, still another large and developed deposit of the region, have been excluded using these rocks in producing of refractories. Among the group of reserve converter dolomite deposits, the best rock properties have been found in four of them, i.e., Chruszczobród, Chruszczobród I, Chruszczobród II and Libiąż Wielki. The survey presented indicates that there are some possibilities of including dolomites of the Winna and, to a lesser degree, Radkowice-Podwole deposits as the raw materials in manufacturing of refractories. Again, more detailed analyses of the chemical composition and petrographical development, mainly of the grain size distribution, would be required. Dolomitic marbles of the Lower Silesia region represent a separate problem. Traditionally, they have been considered to be non-applicable in manufacturing of refractories because of too coarse grain size of these rocks. It should be stressed, however, that the Lower Silesian marbles occur in several varieties and among them also fineand coarse-grained dolomites occur. Their finest and chemically purest varieties can be an interesting option in extending the basis of refractory dolomitic raw materials in Poland, although selective quarrying would be required in such a case.

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Authors and Affiliations

Bogusław Bąk
Barbara Radwanek-Bąk
Piotr Wyszomirski
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Abstract

The Bravaisberget Formation in Spitsbergen embraces an organic carbon-rich, clastic sequence that reflects a general shallow shelf development of the Middle Triassic depositional system in Svalbard . New observations and measurements of the type section of the formation at Bravaisberget in western Nathorst Land allow to present detailed lithostratigraphical subdivision of the formation, and aid to reconstruct its depositional history. The subdivision of the formation ( 209 m thick at type section) into the Passhatten, Somovbreen, and Van Keulenfjorden members is sustained after Mørk et al. (1999), though with new position of the boundary between the Passhatten and Somovbreen mbs. The Passhatten Mb is defined to embrace the black shale-dominated sequence that forms the lower and middle parts of the formation ( 160 m thick). The Somovbreen Mb ( 20 m thick) is confined to the overlying, calcite-cemented sequence of marine sandstones. The Van Keulenfjorden Mb ( 29 m thick) forms the topmost part of the formation composed of siliceous and dolomitic sandstones. The formation is subdivided into twelve informal units, out of which eight is defined in the Passhatten Mb (units 1 to 8), two in the Somovbreen Mb (units 9 and 10), and also two in the Van Keulenfjorden Mb (units 11 and 12). Units 1, 3, 5, 7 and 9 contain noticeable to abundant phosphorite, and are interspaced by four black shale sequences (units 2, 4, 6, and 8). Unit 9 passes upwards gradually into the main sandstone sequence (unit 10) of the Somovbreen Mb. The base of the Van Keulenfjorden Mb is a discontinuity surface covered by thin phosphorite lag. The Van Keulenfjorden Mb consists of two superimposed sandstone units (units 11 and 12) that form indistinct coarsening-upward sequences. The Bravaisberget Fm records two consequent transgressive pulses that introduced high biological productivity conditions to the shelf basin. The Passhatten Mb shows pronounced repetition of sediment types resulting from interplay between organic-prone, fine-grained environments, and clastic bar environments that focused phosphogenesis. The lower part of the member (units 1 to 5) contains well-developed bar top sequences with abundant nodular phosphorite, which are under- and overlain by the bar side sequences grading into silt- to mud-shale. The upper part of the member (units 6 to 8) is dominated by mud-shale, showing the bar top to side sequence with recurrent phosphatic grainstones in its middle part. Maximum stagnation and deep-water conditions occurred during deposition of the topmost shale sequence (unit 8). Rapid shallowing trend terminated organic-rich environments of the Passhatten Mb, and was associated with enhanced phosphogenesis at base of the Somovbreen Mb (unit 9). Bioturbated sandstones of the Somovbreen Mb (unit 10) record progradation of shallow-marine clastic environments. The sequence of the Van Keulenfjorden Mb (units 11 and 12) was deposited in brackish environments reflecting closure of the Middle Triassic basin in western Svalbard .

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Authors and Affiliations

Krzysztof P. Krajewski
Przemysław Karcz
Ewa Woźny
Alte Mørk
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Abstract

The organic carbon (OC)-rich, black shale succession of the Middle Triassic Bravaisberget Formation in Spitsbergen contains scattered dolomite-ankerite cement in coarser-grained beds and intervals. This cement shows growth-related compositional trend from non-ferroan dolomite (0–5 mol % FeCO3) through ferroan dolomite (5–10 mol % FeCO3) to ankerite (10–20 mol % FeCO3, up to 1.7 mol % MnCO3) that is manifested by zoned nature of composite carbonate crystals. The d13C (-7.3‰ to -1.8‰ VPDB) and d18O (-9.4‰ to -6.0‰ VPDB) values are typical for burial cements originated from mixed inorganic and organic carbonate sources. The dolomite-ankerite cement formed over a range of diagenetic and burial environments, from early post-sulphidic to early catagenic. It reflects evolution of intraformational, compaction-derived marine fluids that was affected by dissolution of biogenic carbonate, clay mineral and iron oxide transformations, and thermal decomposition of organic carbon (decarboxylation of organic acids, kerogen breakdown). These processes operated during Late Triassic and post-Triassic burial history over a temperature range from approx. 40°C to more than 100°C, and contributed to the final stage of cementation of the primary pore space of siltstone and sandstone beds and intervals in the OC-rich succession.

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Authors and Affiliations

Krzysztof P. Krajewski
Ewa Woźny
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Abstract

The new rich collection of fossil fish remains obtained during the Polish Spitsbergen Expedition of 1998 includes many isolated shark teeth, mostly of the genera Lissodus, Hybodus and Acrodus. The shark microfossils from the Hornsund area (South Spitsbergen) described here and the analysis of the histology of Lissodus teeth contribute to a better understanding of the previously described Early Triassic fish fauna from that region (Birkenmajer and Jerzmańska 1979). There is the evidence for coexistence of two types of histology within a single taxon what closes the discussion considering ortho- and osteodentine as a taxonomic factor.

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Authors and Affiliations

Błażej Błażejowski
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Abstract

The Trinity Peninsula Group (Permo-Triassic?) at Hope Bay, northern Antarctic Peninsula, is represented by the Hope Bay Formation, more than 1200 m thick. It is subdivided into three members: the Hut Cove Member (HBF,), more than 500 m thick (base unknown), is a generally unfossiliferous marine turbidite unit formed under anaerobic to dysaerobic conditions, with trace fossils only in its upper part; the Seal Point Member (HBF2), 170—200 m thick, is a marine turbidite unit formed under dysaerobic conditions, with trace fossils and allochthonous plant detritus; the Scar Hills Member (HBF3), more than 550 m thick (top unknown), is a predominantly sandstone unit rich in plant detritus, probably formed under deltaic conditions. The supply of clastic material was from northeastern sources. The Hope Bay Formation was folded prior to Middle Jurassic terrestrial plant-bearing beds (Mount Flora Formation), from which it is separated by angular unconformity. Acidic porphyritic dykes and sills cut through the Hope Bay Formation. They were probably feeders for terrestrial volcanics of the Kenney Glacier Formation (Lower Cretaceous) which unconformably covers the Mount Flora Formation. Andean-type diorite and gabbro plutons and dykes (Cretaceous) intrude the Hope Bay Formation, causing thermal alteration of its deposits in a zone up to several hundred metres thick. All the above units are displaced by two system of faults, an older longitudinal, and a younger transversal, of late Cretaceous or Tertiary age.

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Authors and Affiliations

Krzysztof Birkenmajer
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Abstract

Lithic fragments including quartz grains occur infrequently in the shallow-marine limestone sequence of the Fatra Formation deposited in the tensional intra-shelf depression of the Central Western Carpathians during the Rhaetian. Nevertheless, their study can bring data answering questions of sources, palaeogeodynamic arrangement, and processes at the end of the Triassic. In this study, we examined optically the cathodoluminescence (CL) colours of single quartz grains from the Kardolína section (Tatra Mts, Slovakia). These colours reveal a dominance of grains derived from regionally metamorphosed and plutonic rocks. Grains of hydrothermal and pegmatite origin are less frequent. Some of the quartz grains show recycled cement rims suggesting at least a second cycle origin. This sedimentary basin was situated near to the passive margin formed by the Variscan consolidated terrains of the Vindelician Highlands. Our study of the CL colours of quartz grains contributes to the elucidation of the nature of the rocks of the vanished Vindelician mountain belt.
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Authors and Affiliations

Marek Vďačný
1
Jozef Michalík
1

  1. Earth Science Institute of the Slovak Academy of Sciences, Dúbravská cesta 9, P.O. BOX 106, 840 05 Bratislava, Slovakia
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Abstract

The Passhatten Member (Anisian–Ladinian) is the most westward exposure of the Middle Triassic sedimentary sequence of Spitsbergen. The member has an average organic carbon of 2.21 wt %. The sediments were deposited in a shallow shelf environment under conditions of high biological productivity stimulated by a well−developed upwelling system and an enhanced nutrient supply from land areas. The high biological productivity caused a high supply of organic particles to the shelf bottom. Decomposition of organic matter initiated oxygen deficiency in the bottom waters; however, bottom water dynamics on the shallow shelf temporarily replenished the oxygen. Consequently, the Passhatten Mb section is bioturbated, even in thick black shale horizons and consists of alternately spaced lithological layers with variable organic carbon content. The organic matter is dominated by type II kerogen with a mixture of strongly altered marine and/or land derived organic matter. Calculated initial hydrogen index values suggest oil−prone organic matter similar to kerogen I and II types. The organic matter is in the upper intermediate stage of thermo−catalytic alteration, close to the cata− and metagenetic boundary. Maturity indicators including Rock−Eval, Maximum Temperature, Organic Matter Transformation Ratio, Residual Carbon content, as well as the volume of methane generated suggest mature to overmature organic matter. Methane potential retained in the black shales sequence is significant. Unexpelled gas is estimated at 395 mcf/ac−ft for the examined section.
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Authors and Affiliations

Przemysław Karcz
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Abstract

The Fleming Fjord Formation (Jameson Land, East Greenland) documents a diverse assemblage of terrestrial vertebrates of Late Triassic age. Expeditions from the turn of the 21st century have discovered many important fossils that form the basis of our current knowledge of Late Triassic Greenlandic faunas. However, due to the scarcity and incompleteness of the fossils and their insufficient study, our understanding of the taxonomic diversity of the Fleming Fjord Formation is hindered. Here, we report the preliminary findings of a Polish−Danish expedition to the Fleming Fjord Formation that took place in 2014. Three areas were visited – the fairly well known MacKnight Bjerg and Wood Bjerg and the virtually unexplored Liasryggen. MacKnigth Bjerg and Liasryggen yielded fossils which promise to significantly broaden our knowledge of vertebrate evolution in the Late Triassic. Stem−mammal remains were discovered at Liasryggen. Other fossils found at both sites include remains of actinopterygians, sarcopterygians, temnospondyl amphibians and various archosaurs (including early dinosaurs). Numerous vertebrate trace fossils, including coprolites, pseudosuchian footprints, theropod and sauropodomorph dinosaur tracks, were also discovered. Newly discovered skeletal remains as well as abundant trace fossils indicate higher tetrapod diversity in the Late Triassic of Greenland than previously thought. Trace fossils also allow inferences of early theropod and sauropodomorph dinosaur behaviour.
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Authors and Affiliations

Tomasz Sulej
Andrzej Wolniewicz
Niels Bonde
Błażej Błażejowski
Grzegorz Niedźwiedzki
Mateusz Tałanda
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Abstract

A rich collection of exceptionally preserved Lower Triassic fossil fish remains obtained during the Polish Spitsbergen Expedition of 2005 includes many isolated teeth believed to belong to a saurichthyid actinopterygian. Stable isotope analysis ( d 13 C and d 18 O) of putative Saurichthys teeth from the Hornsund area (South Spitsbergen) acting as a paleoenvironmental proxy has permitted trophic−level reconstruction and comparison with other Lower Triassic fish teeth from the same location. The broader range of d 13 C values obtained for durophagous teeth of the hybodont selachian, Lissodus , probably reflects its migratory behaviour and perhaps a greater feeding diversity. X−ray microcomputed tomography (XMT), a non−destructive technique, is used for the first time in order to elucidate de − tails of tooth histology, the results of which suggest that the method has considerable potential as a future analytical tool.
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Authors and Affiliations

Błażej Błażejowski
Christopher J. Duffin
Piotr Gieszcz
Krzysztof Małkowski
Marcin Binkowski
Michał Walczak
Samuel A. McDonald
Philip J. Withers

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