Dennigkofenweg 33


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Ikenoue T.,Marine Ecology Research Institute MERI | Bjorklund K.R.,University of Oslo | Dumitrica P.,Dennigkofenweg 33 | Krabberod A.K.,University of Oslo | And 3 more authors.
Marine Micropaleontology | Year: 2016

Radiolarians in the Arctic Ocean have been studied lately in both plankton and sediment trap samples in the Chukchi Sea area. These studies have shed light on new radiolarian taxa, especially within the order Entactinaria, including two new species of Joergensenium, Joergensenium arcticum from the western Arctic Ocean, so far restricted to the Pacific Winter Water in the Chukchi Sea, and Joergensenium clevei hitherto found in the northern part of the Norwegian Sea south of the Fram Strait. The taxonomic position of the order Entactinaria is discussed and the genus Joergensenium has been emended. We have also observed in detail the internal structure of Joergensenium arcticum using Microfocus X-ray Computed Tomography and have utilized three-dimensional imaging for the first time in a species description. © 2016 Elsevier B.V.

Robertson A.H.F.,University of Edinburgh | Parlak O.,Cukurova University | Yldrm N.,Directorate of Mineral Research and Exploration MTA | Dumitrica P.,Dennigkofenweg 33 | Tasl K.,Mersin University
International Journal of Earth Sciences | Year: 2016

Evidence of rifting and continental break-up to form the S Neotethys is found within the volcanic-sedimentary Koçali Complex. This is a folded, thrust-imbricated succession that includes lavas, volcaniclastic sediments, pelagic carbonates, radiolarites and manganiferous deposits. Interbedded ribbon cherts contain radiolarians of Late Triassic to Late Jurassic age. The lower part of the succession of Mid?-Late Triassic age (Tarasa Formation) is dominated by enriched mid-ocean ridge basalt (E-MORB). The overlying Late Triassic to Mid-Jurassic interval (Konak Formation) is characterised by intercalations of ocean island basalt and E-MORB. Taking account of structural position, the basalts erupted within the outer part of a continent–ocean transition zone. Continental break-up probably occurred during the Late Triassic (Carnian–Norian). Early to Mid-Jurassic lavas and volcaniclastic sediments record volcanism probably after continental break-up. In addition, the Karadut Complex is a broken formation that is located at a relatively low structural position just above the Arabian foreland. Pelagic carbonates, redeposited carbonates and radiolarites predominate. Radiolarians are dated as Early to Mid-Jurassic and Late Cretaceous in age. The pelagic carbonates include planktic foraminifera of Late Cretaceous age. The Karadut Complex resulted from the accumulation of calcareous gravity flows, pelagic carbonate and radiolarites in a relatively proximal, base-of-slope setting. After continental break-up, MORB and ophiolitic rocks formed within the S Neotethys further north. Tectonic emplacement onto the Arabian platform took place by earliest Maastrichtian time. Regional interpretation is facilitated by comparisons with examples of Triassic rifting and continental break-up in the eastern Mediterranean region and elsewhere. © 2015, Springer-Verlag Berlin Heidelberg.

Dumitrica P.,Dennigkofenweg 33 | Dumitrica P.,Institute Of Geologie Et Paleontologie
Revue de Micropaleontologie | Year: 2011

Based on the detailed morphological study of the type species of the genus Multisphaera Nazarov and Afanasieva, the author emends the status and diagnosis of this genus and of the subfamily Multisphaerinae Nazarov and Afanasieva. He found that the initial spicule of the type species is not multi-rayed, as initially thought, but a tetrahedral spicule. Accordingly, the genus is assigned to the former tribe Tetrentactiniini Kozur and Mostler that is herein raised to the family rank and comprises all Upper Devonian to lower Permian genera with a tetrahedral initial spicule. Consequently, the subfamily Multisphaerinae is considered a junior synonym of the family Tetrentactiniidae. To better solve the taxonomic problems of this family the author compares the morphological diversity of its members with the morphological diversity of the lower Tithonian (uppermost Jurassic) tetrahedral spicule-bearing entactinarian Radiolaria occurring in the Solnhofen area, southern Germany. Although these genera have the same type of spicule as the Paleozoic ones, they seem to belong to a new family because between the lower Tithonian and the lower Permian genera there is a long time interval of about 120. Ma in which no radiolarians with a tetrahedral initial spicule have been recorded so far. This comparison shows once more the conservative character of the initial spicule and the wide morphological diversity of the extraspicular shell. © 2011 Elsevier Masson SAS.

Moix P.,University of Lausanne | Beccaletto L.,Bureau de Recherches Géologiques et Minières | Masset O.,ETH Zurich | Kozur H.W.,Rezsu u. 83 | And 4 more authors.
Turkish Journal of Earth Sciences | Year: 2011

Our paper aims to give a thorough description of the infra-ophiolitic mélanges associated with the Mersin ophiolite. We propose new regional correlations of the Mersin mélanges with other mélange-like units or similar series, located both in southern Turkey and adjacent regions. The palaeotectonic implications of the correlations are also discussed. The main results may be summarized as follows: the infra-ophiolitic mélange is subdivided into two units, the Upper Cretaceous Sorgun ophiolitic mélange and the Ladinian-Carnian Hacialani{dotless} mélange. The Mersin mélanges, together with the Antalya and Mamonia domains, are represented by a series of exotic units now found south of the main Taurus range, and are characteristic of the South-Taurides Exotic Units. These mélanges clearly show the mixed origin of the different blocks and broken formations. Some components have a Palaeotethyan origin and are characterized by Pennsylvanian and Lower to Middle Permian pelagic and slope deposits. These Palaeotethyan remnants, found exclusively in the Hacialani{dotless} mélange, were reworked as major olistostromes in the Neotethys basin during the Eo-Cimmerian orogenic event. Neotethyan elements are represented by Middle Triassic seamounts and by broken formations containing typical Neotethyan conodont faunas such as Metapolygnathus mersinensis Kozur & Moix and M. primitius s. s., both present in the latest Carnian interval, as well as the occurrence of the middle Norian Epigondolella praeslovakensis Kozur, Masset & Moix. Other elements are clearly derived from the former north Anatolian passive margin and are represented by Huǧlu-type series including the Upper Triassic syn-rift volcanic event. These sequences attributed to the Huǧlu-Pindos back-arc ocean were displaced southward during the Late Cretaceous obduction event. The Tauric elements are represented by Eo-Cimmerian flysch-like and molasse sequences intercalated in Neotethyan series. Additionally, some shallow-water blocks might be derived from the Bolkardaǧ paraautochthonous and the Taurus-Beydaglari marginal sequences. ©TÜBİTAK.

O'Dogherty L.,University of Cádiz | Carter E.S.,Portland State University | Gorican S.,Paleontoloski Institute Ivana Rakovca ZRC SAZU | Dumitrica P.,Dennigkofenweg 33
Geological Society Special Publication | Year: 2010

This paper summarizes 30 years of research on the biostratigraphy of Triassic radiolarians and presents a correlation of currently-used radiolarian zonations established in North America, Europe, Japan and Far East Russia. An up-to-date stratigraphic distribution of all hitherto described and still valid Triassic genera is provided. This new range chart consists of 282 genera and allows an accurate dating to substage level. It also clearly manifests general trends in radiolarian evolution through the Triassic. The end-Permian extinction, the most severe extinction in the history of radiolarians, was followed by a long recovery until the early Anisian. The middle and late Anisian were then characterized by a rapid explosion of new morphologies. Maximum generic diversity was attained during the early Carnian, but the first severe extinctions also occurred in the Carnian. A progressive decline of diversity took place through the Norian and Rhaetian, and ended in a mass extinction around the Triassic-Jurassic boundary. © The Geological Society of London 2010.

Carter E.S.,Portland State University | Gorican S.,Paleontoloski Institute Ivana Rakovca | Guex J.,University of Lausanne | O'Dogherty L.,University of Cádiz | And 5 more authors.
Palaeogeography, Palaeoclimatology, Palaeoecology | Year: 2010

Jurassic radiolarians from 220 samples in Queen Charlotte Islands, B.C., Williston Lake, B.C., east-central Oregon, Baja California Sur, southern Spain, Austria, Slovenia, Turkey, Oman, Japan and Argentina were studied in order to construct global zonation for the Pliensbachian, Toarcian and Aalenian stages. Well-preserved faunas from continuous stratigraphic sections in Queen Charlotte Islands provide the most detailed record for this time interval, and all collections are tied to North American ammonite zones or assemblages. Collections from nearly all other areas lack independent dating except for early Toarcian carbon-isotope dating in Slovenia and late Aalenian ammonites in Spain.A database of 197 widely distributed updated taxonomic species was used to construct a Unitary Association (UA) zonation for the interval. A global sequence of 41 UAs was obtained for the top of the Sinemurian to the base of the Bajocian. The first and the last UAs represent the Late Sinemurian and the Early Bajocian respectively. The remaining 39 UAs were merged into nine zones (four Early Pliensbachian, one Late Pliensbachian, one Early Toarcian, one Middle-Late Toarcian, and two Aalenian) according to prominent radiolarian faunal breaks and ammonite data. The new zones are the Canutus tipperi - Katroma clara Zone (latest Sinemurian/earliest Pliensbachian); Zartus mostleri - Pseudoristola megaglobosa, Hsuum mulleri - Trillus elkhornensis and Gigi fustis - Lantus sixi zones (Early Pliensbachian); Eucyrtidiellum nagaiae - Praeparvicingula tlellensis Zone (Late Pliensbachian); Napora relica - Eucyrtidiellum disparile Zone (Early Toarcian); Elodium pessagnoi - Hexasaturnalis hexagonus Zone (Middle and Late Toarcian); Higumastra transversa - Napora nipponica Zone (early Aalenian); and Mirifusus proavus - Transhsuum hisuikyoense Zone (late Aalenian). These zones can be correlated worldwide and link previously established UA zonations for the Hettangian-Sinemurian and the Middle to Upper Jurassic. The new zonation allows high-resolution dating in the studied interval and provides a solid basis for analyzing faunal turnovers and the paleobiogeography of Jurassic radiolarians. © 2010 Elsevier B.V.

Guex J.,University of Lausanne | O'Dogherty L.,University of Cádiz | Carter E.S.,Portland State University | Gorican S.,PaleontoloSki Institute Ivana Rakovca ZRC SAZU | And 2 more authors.
Geobios | Year: 2012

Radiolarians are Cambrian to recent holoplanktonic marine protists with morphologically very diverse siliceous skeletons. In the Mesozoic, two main groups are differentiated: nassellarians (mostly conical, composed of one or more consecutive segments) and spumellarians s.l. (generally spherical, composed of one or more concentrical shells). Following the extensive radiolarian research over the past decades, it is now possible to trace the development of some Mesozoic radiolarians through time and to reliably reconstruct several phyletic lineages. In this study, we analyse some lineages with well-marked trends in skeletal development and compare these trends with those observed in other marine organisms. The most usual geometrical transformations occurring in radiolarians are characterized by an increase of the surface of the shell. In several nassellarians, we observe a progressive inflation of the test, leading to a spherization. In some groups, such a trend leads to cryptocephalization, a phenomenon analogous to the orbulinization of some Tertiary foraminifers. The development of a terminal tube or of apertural arches is also frequent in the nassellarians. In many respects, the transformations observed in the spumellarians are related to the same kind of geometrical modifications. For example, the addition of an arch to a polar spine in Baumgartneria, of a ring in the Saturnalids, of a button or spine also in the ring of Aurisaturnalis, are clear examples of an increase of the shell surface through time. Proterogenesis is also frequent in nassellarians and spumellarians s.l., especially in the Pyloniaceae and Centrocubidae where new structures first develop in the earliest ontogenetic stage. The initial antapical spicule frequently evolves by doubling or quadrupling of the antapical spine, leading to entirely new modes of growth in subsequent descendants and to forms which are cryptogenic with regard to their ancestors. During extinction crises corresponding to highly stressful periods, radiolarians tend to lose the structures which were developed during their preceding evolution: loss of the ring in the Axoprunids, loss of the twisting of the spines in Tipperella, disappearance of inflated nassellarians in the Early Jurassic, etc. Such losses lead to the reappearance of primitive characters. © 2012.

Velledits F.,Limestone Bt. andrassy Gy. u. 6 | Pero C.,Geological Research Group | Blau J.,Feldbergstrasse 5 | Senowbari-Daryan B.,Friedrich - Alexander - University, Erlangen - Nuremberg | And 7 more authors.
Rivista Italiana di Paleontologia e Stratigrafia | Year: 2011

The 1:10,000 scale mapping of the southern part of the Aggtelek Plateau (Western Carpathians, Silica Nappe, NE Hungary) and the study of five sections revealed two Middle Triassic reef bodies. In the late Pelsonian the uniform Steinalm Platform was drowned and dissected due to the Reifling Event. A connection with the open sea was established, indicated by the appearance of gladigondolellid conodonts from the early Illyrian. Basins and highs were formed. In the NW part of the studied area lower - middle? Illyrian basinal carbonates were followed by a platform margin reef (early? - middle Illyrian; reef stage 1) developed on a morphological high. This is the oldest known Triassic platform margin reef within the Alpine-Carpathian region. The reef association is dominated by sphinctozoans and microproblematics. The fossils are characteristic of the Wetterstein - type reef communities. Differently from this in the SE part of the studied region a basin existed from the late Pelsonian until the early Ladinian. During the late Illyrian - early Ladinian, the reef prograded to the SE, and reef stage 2 was established. Meanwhile, on the NW part of the platform a lagoon was formed behind the reef. Based on our palaeontological study the stratigraphic range of Colospongia catenulata, Follicatena cautica, Solenolmia manon manon, Vesicocaulis oenipontanus must be extended down to the middle Illyrian.

Dumitrica P.,Dennigkofenweg 33 | Tekin U.K.,Hacettepe University | Bedi Y.,General Directorate of Mineral Research and Exploration
Palaontologische Zeitschrift | Year: 2010

This article is a taxonomic study of the radiolarian species of the superfamilies Eptingiacea and Saturnaliacea occurring in the middle Carnian fauna from the Köseyahya section, near the town of Elbistan, southeastern Turkey. This fauna is characteristic of the Tetraporobrachia haeckeli Radiolarian Zone as defined in Austria and later found also in Turkey and Oman. It comes from an 8 m thick succession of clayey/cherty limestones from the lower part of the section. In addition, a few species from the late Ladinian and Carnian from Oman and the early Norian from Alaska have also been included in this study, in order to improve some generic diagnoses and to show the diversity and evolutionary trends of some genera. 32 radiolarian species of which 22 are new are described and illustrated, and assigned to 16 genera of which three are new (Capnuchospyris, Veleptingium, and Triassolaguncula). The diagnoses of some species, genera, subfamilies and families have been revised, and the family Eptingiidae has been raised to the rank of superfamily. © 2009 Springer-Verlag.

O'Dogherty L.,University of Cádiz | De Wever P.,French Natural History Museum | Gorican S.,Paleontoloski Institute Ivana Rakovca ZRC SAZU | Carter E.S.,Portland State University | Dumitrica P.,Dennigkofenweg 33
Palaeoworld | Year: 2011

The recent systematic and stratigraphic revision of all described Mesozoic radiolarian genera (O'Dogherty et al., 2009a,b,c) represents the state of the art in the taxonomy of this group. Using this information, we have improved the stratigraphy of Mesozoic families by redefining their ranges at the substage precision.Our analysis shows a clear change in faunal composition at the Permo-Triassic boundary (only 15 families cross: 2 Albaillellaria, 4 Latentifistularia, 3 Entactinaria, 2 Nassellaria and 4 Spumellarian) followed by an explosion at the Middle Triassic. Through the Late Triassic, 32 families began to go extinct, leading to a drastic disappearance of typical Triassic morphotypes. However, the Triassic-Jurassic boundary does not record a similar extinction at the family level; 37 families and subfamilies apparently crossed the boundary. Paradoxically, the revision of genera has shown the survival of only 30 genera at this boundary belonging to 23 families. The reason of such a discrepancy is the virtual crossing of 14 families at Triassic-Jurassic boundary. That is, families having representatives in both the Triassic and Jurassic, but without any record close to the boundary.Similarly, these discontinuities in the ranges are observed throughout the Jurassic and Cretaceous, but especially at the Cretaceous-Paleogene boundary, where 21 families are crossing virtually. Among the orders, Entactinaria presents proportionally the highest number of families with discontinuous ranges. The reason could be related to the scarcity of studies on this group whose systematic classification needs a good knowledge of the initial spicule. We analyze in detail the major discontinuities observed in the range of some families. Explanations considering discontinuous fossil record, limited knowledge on phylogenetic relationships, or possible homeomorphism are proposed. © 2010 Elsevier Ltd and Nanjing Institute of Geology and Palaeontology, CAS.

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