Martin-Luther-Universität Halle-Wittenberg: Elektronische Zeitschriften
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Second addendum to the Leafhoppers and Planthoppers of Germany (Hemiptera: Auchenorrhyncha)
Full text linkThis paper presents new faunistic and ecological data on 21 species of planthoppers and leafhoppers in Germany. Delphax armeniacus An., Javesella bottnica Huld., Micantulina teucrii (Cer.), Ficocyba ficaria (Horv.), Placotettix taeniatifrons (Kbm.), Allygidius furcatus (Ferr.), Phlogotettix cyclops (M. & R.) and Thamnotettix exemtus Mel. are new to the country. New distributional and ecological data are given for Megamelodes lequesnei W. Wg., Cercopis arcuata Fieb., Macropsis mulsanti (Fieb.), Dryodurgades antoniae (Mel.), Hishimonus hamatus Kuoh, Maiestas horvathi (Then), Anoplotettix fuscovenosus (Ferr.), Cicadula placida (Horv.), Ederranus discolor (J. Shlb.), Paralimnus lugens (Horv.), Psammotettix albomarginatus W. Wg., Pinumius areatus (St.l) and Cosmotettix evanescens Oss. An analysis of 28 species recorded as new for Germany in the last two decades showed that the increase is caused in equal shares by better taxonomic and faunistic knowledge on the one hand and real ecological changes through anthropogenic introductions and northward range expansions (presumably driven by climatic factors) on the other hand.This paper presents new faunistic and ecological data on 21 species of planthoppers and leafhoppers in Germany. Delphax armeniacus An., Javesella bottnica Huld., Micantulina teucrii (Cer.), Ficocyba ficaria (Horv.), Placotettix taeniatifrons (Kbm.), Allygidius furcatus (Ferr.), Phlogotettix cyclops (M. & R.) and Thamnotettix exemtus Mel. are new to the country. New distributional and ecological data are given for Megamelodes lequesnei W. Wg., Cercopis arcuata Fieb., Macropsis mulsanti (Fieb.), Dryodurgades antoniae (Mel.), Hishimonus hamatus Kuoh, Maiestas horvathi (Then), Anoplotettix fuscovenosus (Ferr.), Cicadula placida (Horv.), Ederranus discolor (J. Shlb.), Paralimnus lugens (Horv.), Psammotettix albomarginatus W. Wg., Pinumius areatus (St.l) and Cosmotettix evanescens Oss. An analysis of 28 species recorded as new for Germany in the last two decades showed that the increase is caused in equal shares by better taxonomic and faunistic knowledge on the one hand and real ecological changes through anthropogenic introductions and northward range expansions (presumably driven by climatic factors) on the other hand
Nachruf Professor Dr. Dr. Herbert Pöllmann: Eine lebenslange Passion für Minerale und Gesteine
No full text19th Symposium Tectonics, Structural Geology and Geology of Crystalline Rocks: Volume I: Abstracts
No full text
Brachychirotherium aus dem Coburger Sandstein (Mittlerer Keuper, Karn/Nor) in Nordbayern: Brachychirotherium of the Coburger Sandstein (Middle Keuper, Carnian/Norian) of Northern Bavaria
Full text linkBEURLEN (1950) stellte Brachychirotherium nach Funden von Tetrapodenfährten aus dem Coburger Sandstein auf und grenzte den Formenkreis aufgrund der besonderen Fuß- und Handform von den bis dahin bekannten Chirotherien ab. Das war der Erstnachweis eines neuen Ichnogenus im Sandsteinkeuper der Oberen Trias. In der vorliegenden Arbeit wurden das Originalmaterial von BEURLEN sowie weitere Funde aus dem Coburger Sandstein und anderen Horizonten des Sandsteinkeupers untersucht. Es handelt sich um Belegmaterial von Brachychirotherium begleitet von tridactylen Formen („Coelurosaurichnus") und lacertoiden Formen (Rhynchosauroides) auf insgesamt 138 Sandsteinplatten. Die Revision von Brachychirotherium ergab die emendierte Diagnose des Ichnogenus ausgehend vom Genotypus B. hassfurtense und der nahestehenden Ichnospezies B. thuringiacum sowie die Festlegung der jeweiligen Lectotypen. B. hassfurtense ist auf denTypushorizont, den Coburger Sandstein in Nordbayern beschränkt. B. thuringiacum kommt im Coburger Sandstein, im liegenden Blasensandstein in Südthüringen und im hangenden Unteren Burgsandstein in Nordbayern vor. Nach Messungen an 60 Fußausgüssen erweisen sich die Kreuzachse sowie die Proportionen der Zehengruppe 1-IV als maßgebliche Artkriterien. Die erstmalige Anwendung der Landmark-Analyse auf Tetrapodenfährten ergibt für Brachychirotherium Hinweise auf eine erweiterte ichnospezifische Differenzierbarkeit. Das sind Ansätze für weiterführende Studien zur Ichnologie von Tetrapoden mit Hilfe der Landmark-Analyse. Die vorliegende Arbeit ist insofern auch ein möglicher Ansatz zur Analyse der Trias-Chirotherien unter neuen Vorzeichen. Von den bisher 12 unter Brachychirotherium aus der Trias bestimmten Arten sind für das Ichnogenus nur die vier aus der Oberen Trias morphologisch signifikant: B. hassfurtense, B. thuringiacum, B. parvum und B. eyermani. Das bestätigen weitere Nachweise, welche aus der Passaic Formation und der Chinle Group in Nordamerika unter Brachychirotherium sp. sowie aus der Molteno Formation in Südafrika unter anderen Namen beschrieben worden sind. Für eine Deutung der Erzeuger stehen nach wie vor Pseudosuchia in der engeren Wahl, allerdings ohne nähere Präferenzen.After discoveries of tetrapod tracks from the Coburger Sandstein, BEURLEN ( 1950) introduced Brachychirotherium, for which the track-forms appear separate from the hitherto known chirotherians by their particular morphology of pes and manus. This was the first record of a new ichnogenus from the Sandsteinkeuper of the Upper Triassic. The present study deals with the original specimens of BEURLEN, and additional material of the Coburger Sandstein and other horizons of the Middle Keuper. On the 138 track-bearing sandstone slabs, Brachychirotherium is associated with tridactyl tracks ("Coelurosaurichnus"), and lacertoid tracks (Rhynchosauroides). The emended diagnosis of Brachychirotherium concerns principally the genotype, B. hassfurtense, and the near related ichnospecies B. thuringiacum, together with the establishment of the lectotypes for both. B. hassfurtense is restricted to the type horizon, the Coburger Sandstein, B. thuringiacwn is recorded from the Coburger Sandstein, from the underlying Blasensandstein of Southern Thuringia, and from the lower Burgsandstein of Northern Bavaria. As a result of the measurements of 60 pes tracks, the cross-axis, and the proportion of the digit groups 1-IV are the most significant criteria for the ichnospecies. The first application of the landmark analysis to discriminate tetrapod tracks points to additional possibilities for the differentiation of ichnospecies within Brachychirotherium. This is, moreover, a working hypothesis for possible progress in the taxonomy of the tetrapod ichnology with the methods of the landmark analysis. This paper could be an hypothesis for the analysis of the Triassic chirotherians along new lines. From the former twelve determined ichnospecies of Brachychirotherium from the Lower to Upper Triassic, only the four ichnospecies of Upper Triassic age are morphologically significant: B. hassfurtense, B. thuringiacum, B. parvum and B. eyermani. This significance is confirmed by records from the Passaic Formation and from the Chinle Group in North America published under Brachychirotherium sp., and by specimens described under different names from the Molteno Formation in South Africa. The interpretation of the trackmakers now concerns, as before, the Pseudosuchia, but without special preferences
Mitteilungen aus dem Institut
Full text linkFestkolloquium zum 60. Geburtstag von Dr. Gerhard Beutler
Prof. (em.) Dr. habil. Manfred Reichstein wurde 70 Jahre alt
50. Todestag von Prof. Johannes Weigelt
International Symposium on the Epicontinental Triassi
Tectonic Critical Phenomena with Dilatancy in Analogue Models
No full textThe dilatancy of soil and rock eludes continuum mechanics, thermodynamics and materials science as it is localized in fractal patterns of shear bands (faults) and/or cracks. As far as shear bands dominate it is captured by a driven succession of saddle points of the specific elastic energy, which are equivalent to a Mohr-Coulomb condition with effective stress, growing friction and waning cohesion. A driven dilatation turns into a spontaneous contraction when the energy reaches a tipping point with regard to the pore volume, then the pore water pressure grows and the stress deviator drops. The implied state variables and rates are defined as quasi-local and -momentary by means of fractional derivatives. Energy-based constitutive equations include a relation of stress and dilatancy with maximal dissipation, while rockburst with dominant cracks is excluded by a criterion. Successions of driven dilatation and spontaneous contraction imply seismogenic mechanical chain reactions, which are enhanced by seismic waves and spreading of pore water. Such mechanisms are observed in sandbox and cell tests, which serve as analogue models beyond usual similarity rules. The scale-independence of features thus. obtained is validated in the companion paper on lithosphere sections
