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Bremen, Germany

Petkovski T.K.,Prirodonaucen Muzej Na Makedonija | Scharf B.,Ellhornstr. 21 | Keyser D.,Biozentrum Grindel und Zoologisches Museum
Zootaxa | Year: 2016

Material from Spitsbergen (Norway) collected by Spitzenberger (1996) was reinvestigated. A new genus Arctocypris and a new species Arctocypris. fuhrmanni n. gen. n. sp. are described in the present paper. A key to the genera of the subfamily Eucypridinae is provided. At the moment Arctocypris n. gen. comprises four species: Arctocypris arctica (Olofsson, 1918) comb. nov.; A. dulcifons (Diebel & Pietrzeniuk, 1969) comb. nov.; A. foveata (Delorme, 1968) comb. nov. and Arctocypris fuhrmanni n. gen., n. sp. Copyright © 2016 Magnolia Press. Source


Zaibi C.,University of Sfax | Scharf B.,Ellhornstr. 21 | Viehberg F.A.,University of Cologne | Keyser D.,Biozentrum Grindel und Zoologisches Museum | Kamoun F.,University of Sfax
Zootaxa | Year: 2013

Since 1928, Henri Gauthier has been the only zoologist to describe the extant non-marine ostracod fauna of Tunisia. In 2010, new samples of living non-marine ostracods were collected from central and southern Tunisia. A complete list of the 41 non-marine ostracods of Tunisia is presented, including the species of Gauthier's work, published Holocene records, and new results from our field study. Historical faunal variations (El Melah Lagoon, Lac de Tunis, Sebkhas El- Guettiate and DreÎaa, and Lac Ichkeul) are briefly discussed and related to recent environmental changes. In 2006, El Melah Lagoon contained a freshwater, brackish, and a marine ostracod assemblage. In the future, this lagoon will probably dry up and become a sebkha. Lac de Tunis has developed from a marine bay over a lagoon connected to the Mediterranean Sea to a brackish/freshwater environment. Sebkhas El-Guettiate and DreÎaa have developed from marine bays to dry salt flats. Lac Ichkeul is eutrophied and has become brackish since the time of Gauthier. We also describe a new species, Psychrodromus tunisicus n. sp., and present a determination key for the genus. The finding of a species of the genus Psychrodromus is the first report of this genus in North Africa. Copyright © 2013 Magnolia Press. Source


Scharf B.,Ellhornstr. 21 | Kmiecik J.,Kohler | Viehberg F.A.,University of Cologne
Journal of Paleolimnology | Year: 2015

We developed and improved methods to extrude sediment out of core tubes and to cut defined layers of sediment in the field. For extrusion we use standard connectable 50-cm sewage tubes or aluminum rods with two lines of holes vertically in equidistance of 0.5 or 1 cm. A stopper at the bottom of the core tube is placed on top of the extruder and the core tube is pushed downwards and stopped by distance pins in the holes. The extruder is independent of the length and diameter of the core tube. A modification of the extrusion equipment can be used for checking lamination of the sediment in the field. In addition, a rubber stopper is described for the extrusion of sandy sediment out of the core tube. A PVC-core cutter is presented that is also capable of sampling watery sediments, and it prevents contamination with metal. The advantages of these devices are the simplicity, handling, robustness and cost efficiency. © 2015, Springer Science+Business Media Dordrecht. Source


Dressler M.,University of Rostock | Schwarz A.,TU Braunschweig | Hubener T.,University of Rostock | Adler S.,University of Rostock | Scharf B.W.,Ellhornstr. 21
Journal of Paleolimnology | Year: 2011

Fossil diatoms from lake sediments have been used to infer both past trophic state and climate conditions. In Europe, climate reconstructions focused on northern and alpine regions because these areas are climatically sensitive and anthropogenic impact was low. In contrast, anthropogenic impact was often high in the central European lowlands, such as northern Germany, beginning in the Neolithic Age, ~3700 BC. Since that time, trophic state change was the main factor that affected diatom assemblages in central European lowland lakes. Therefore, it was considered difficult or impossible to identify climate changes in the region using sedimented diatoms. We used diatom assemblage changes, diatom-inferred total phosphorus concentrations and the relative abundance of planktonic diatoms from sediments of three lakes that differ in their location, size, morphology, catchment area and current trophic state to test whether we could distinguish between trophic state and climate signals over the past 5,000 years in northern Germany. In this study, changes in trophic state and climate were well differentiated. In the study lakes, relative abundance of planktonic diatoms seems to be linked to the length of lake mixing phases. Planktonic diatom abundance decreased during years with shorter mixing duration, and these shorter mixing times probably reflect colder winters. The diatom-inferred periods of short mixing phases from 1000 BC to AD 500 and from AD 1300 to 1800 coincide well with two known cooling phases in Europe and the North Atlantic region. © 2010 Springer Science+Business Media B.V. Source


Pint A.,Friedrich - Schiller University of Jena | Frenzel P.,Eilenburger Strasse 32 | Fuhrmann R.,Friedrich - Schiller University of Jena | Scharf B.,Ellhornstr. 21 | Wennrich V.,University of Cologne
International Review of Hydrobiology | Year: 2012

Cyprideis torosa (Jones, 1850) is a very common brackish water ostracod of the German coasts, but, despite empty valves are found occasionally in surface sediments of some modern inland waters, C. torosa could not be found living in modern athalassic waters of Germany so far. During interglacial periods, including the Holocene, however, fossils of this species are quite common in Central Germany, at a distance of more than 300 km away from the coasts of the Baltic and North Seas. All 31 Quaternary localities with C. torosa known so far from Germany are documented. C. torosa is an indicator for brackish waters and widely used as index-fossil in palaeosalinity reconstructions relying on water chemistry bound morphological changes (nodes, sieve-pores). The comparisons imply a general underestimation of palaeosalinity in oligo- to mesohaline athalassic waters if using nodes and sieve-pores of C. torosa as proxy. A water chemistry (ionic composition) driven morphological response is assumed instead one by salinity only. Palaeosalinity estimations for athalassic waters, relying on morphological variability alone, should therefore be used with caution. Palaeosalinity trends, however, can be detected. Distinguishing thalassic and athalassic sediments with C. torosa is possible by using the associated ostracod fauna as a discriminator. Regarding the ecology and distribution of C. torosa, permanent, brackish, and shallow water bodies under relatively warm conditions are required for its settlement. The source of the salt are brines originating from Zechsteinian or Triassic underground evaporites. Warm and relatively dry climates could enhance the process for such water bodies of becoming salty, a situation present in Holocene Central Germany. The occurrence of C. torosa can therefore be used for palaeoclimatological studies. The most probable migration path of this ostracod species to athalassic waters is by avian transport. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

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