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Fossil spinicaudatan taxonomy heavily relies on carapace features (size, shape, ornamentation) and palaeontologists have greatly refined methods to study and describe carapace variability. Whether carapace features alone are sufficient for distinguishing between species of a single genus has remained untested. In our study, we tested common palaeontological methods on 481 individuals of the extant Australian genus Ozestheria that have been previously assigned to ten species based on genetic analysis. All species are morphologically distinct based on geometric morphometrics (p ≤ 0.001), but they occupy overlapping regions in Ozestheria morphospace. Linear discriminant analysis of Fourier shape coefficients reaches a mean model performance of 93.8% correctly classified individuals over all possible 45 pairwise species comparisons. This can be further increased by combining the size and shape datasets. Nine of the ten examined species are clearly sexually dimorphic but male and female morphologies strongly overlap within species with little influence on model performance. Ornamentation is commonly species‐diagnostic; seven ornamentation types are distinguished of which six are species‐specific while one is shared by four species. A transformation of main ornamental features (e.g. from punctate to smooth) can occur among closely related species suggesting short evolutionary timescales. Our overall results support the taxonomic value of carapace features, which should also receive greater attention in the taxonomy of extant species. The extensive variation in carapace shape and ornamentation is noteworthy and several species would probably have been assigned to different genera or families if these had been fossils, bearing implications for the systematics of fossil Spinicaudata., Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659, https://doi.org/10.5061/dryad.fbg79cnxs

In meiner Master-Arbeit untersuche ich anhand von amerikanischen und sowjetischen Regierungsakten, mit welcher Einschätzung und mit welchen Absichten sich die Reagan-Administration und die sowjetische Führung auf das Treffen von Reagan und Gorbatschow in Reykjavik 1986 vorbereiteten. Zuerst beschreibe ich, wie die Supermächte während der siebziger Jahre erfolglos versuchten, ihren Konflikt diplomatisch beizulegen und zu Beginn der Achtziger wieder zu Konfrontation, Aufrüstung und Drohungen zurückkehrten. US-Präsident Ronald Reagan versuchte die krisengeplagte UdSSR durch ein neues Wettrüsten in den wirtschaftlichen Ruin zu treiben. Die alternde und sterbende sowjetische Führung war nicht in der Lage, mit dieser gefährlichen Situation umzugehen. Erst als Michail Gorbatschow 1985 zum Generalsekretär ernannt wurde, verbesserte sich die Beziehung. Gorbatschow erkannte, dass die Sowjetunion dringend reformiert werden musste und beschloss, mit den USA Frieden zu schließen, um anschließend alle Kraft in die Reformen zu investieren. Dazu suchte er nach einem Weg, den Kalten Krieg zusammen mit Reagan zu beenden. Nachdem ein erstes Treffen mit Reagan 1985 erfolglos verlaufen war, schlug Gorbatschow im Herbst 1986 kurzfristig ein zweites Treffen in Reykjavik vor. Sein Plan war, Reagan mit neuen und spektakulären Vorschlägen zur Abrüstung zu überraschen und auf Island zu einem Abkommen zu drängen, dass die Last des Wettrüstens lindern und den Kalten Krieg entspannen würde. Anhand von amerikanischen und sowjetischen Regierungsakten untersuche und vergleiche ich, wie sich die beiden Lager vor dem Treffen einschätzten und welche Absichten sie für die Verhandlungen hatten. Am Schluss fasse ich die Ergebnisse der Analyse zusammen und ordne die Bedeutung des Treffens in den historischen Kontext des späten Kalten Krieges ein. In this master thesis, I analyze how the Reagan Administration and the Soviet leadership perceived each other before the meeting of Reagan and Gorbachev in Reykjavik in 1986 and how they prepared themselves for the meeting. This is done by analyzing and comparing US foreign relations documents and Soviet politburo files from the era. First, I lay out how the superpowers failed during the Seventies to solve their conflict peacefully and diplomatically. This failure led to a period of renewed confrontation during the early Eighties. US president Ronald Reagan started a new round of arms race designed to lead the Soviet Union to the brink of financial ruin and to win the Cold War. Meanwhile, the sick and aging Soviet leadership in Moscow was unable to respond to this new and dangerous development. Major change arrived in 1985, when Mikhail Gorbachev became General Secretary. Gorbachev realized that the Soviet Union needed to be reformed politically and economically and decided to make peace with the USA in order to free resources for his reform policies. This meant for him to work together with Reagan. After a first summit meeting with Reagan in 1985 failed to produce solutions, Gorbachev proposed a second meeting for the fall of 1986 in Reykjavik. His intention was to surprise Reagan with major new proposals to eliminate nuclear weapons and to force Reagan to sign a disarmament treaty in Reykjavik. His goal was to relieve the Soviet economy of the burden of the arms race and to relax tensions between the superpowers. Using US foreign relation documents and Soviet politburo files, I analyze and compare how the two camps perceived each other before the meeting and assessed their plans for the upcoming negotiations. In the end I summarize my results and contextualize the importance of this meeting in the late Cold War. vorgelegt von Kai Hendrik HARTMANN,B.A. Abweichender Titel laut Übersetzung des Verfassers/der Verfasserin Masterarbeit Universität Graz 2023 1 Zusammenfassung auf deutsch

Extracting information about past tectonic or climatic environmental changes from sedimentary records is a key objective of provenance research. Interpreting the imprint of such changes remains challenging as signals might be altered in the sediment-routing system. We investigate the sedimentary provenance of the Oligocene/Miocene Upper Austrian Northern Alpine Foreland Basin and its response to the tectonically driven exhumation of the Tauern Window metamorphic dome (28 ± 1 Ma) in the Eastern European Alps by using the unprecedented combination of Nd isotopic composition of bulk-rock clay-sized samples and partly previously published multi-proxy (Nd isotopic composition, trace-element geochemistry, U-Pb dating) sand-sized apatite single-grain analysis. The basin offers an excellent opportunity to investigate environmental signal propagation into the sedimentary record because comprehensive stratigraphic and seismic datasets can be combined with present research results. The bulk-rock clay-sized fraction εNd values of well-cutting samples from one well on the northern basin slope remained stable at ∼−9.7 from 27 to 19 Ma but increased after 19 Ma to ∼−9.1. In contrast, apatite single-grain distributions, which were extracted from 22 drill-core samples, changed significantly around 23.3 Ma from apatites dominantly from low-grade (

1. Morphometrics are fundamental for the analysis of size and shape in fossils, particularly because soft parts or DNA are rarely preserved and hard parts such as shells are commonly the only source of information. Geometric morphometrics, that is, landmark analysis, is well established for the description of shape but it exhibits a couple of shortcomings resulting from subjective choices during landmarking (number and position of landmarks) and from difficulties in resolving shape at the level of micro-sculpture. 2. With the aid of high-resolution 3D scanning technology and analyses of fractal dimensions, we test whether such shortcomings of linear and landmark morphometrics can be overcome. As a model group, we selected a clade of modern viviparid gastropods from Lake Lugu, with shells that show a high degree of sculptural variation. Linear and landmark analyses were applied to the same shells in order to establish the fractal dimensions. The genetic diversity of the gastropod clade was assessed. 3. The genetic results suggest that the gastropod clade represents a single species. The results of all morphometric methods applied are in line with the genetic results, which is that no specific morphotype could be delimited. Apart from this overall agreement, landmark and fractal dimension analyses do not correspond to each other but represent data sets with different information. Generally, the fractal dimension values quantify the roughness of the shell surface, the resolution of the 3D scans determining the level. In our approach, we captured the micro-sculpture but not the first-order sculptural elements, which explains that fractal dimension and landmark data are not in phase. 4. We can show that analyzing fractal dimensions of gastropod shells opens a window to more detailed information that can be considered in evolutionary and ecological contexts. We propose that using low-resolution 3D scans may successfully substitute landmark analyses because it overcomes the subjective landmarking. Analyses of 3D scans with higher resolution than used in this study will provide surface roughness information at the mineralogical level. We suggest that fractal dimension analyses of a combination of differently resolved 3D models will significantly improve the quality of shell morphometrics.

The African baobab, Adansonia digitata L., has great paleoclimatological potential because of its wide distributional range and millennial length life span. However, dendroclimatological approaches are hampered by dating uncertainties due to its unique, parenchyma-dominated stem anatomy. Here, securely dated time series of annual wood increment growth and intra-ring stable isotopes of carbon and oxygen of cellulose for a baobab tree from Oman covering 1941 to 2005 were established and tested for relationships to hydroclimate variability. Precise dating with the atomic bomb peak (ABP) using highly resolved 14C measurements confirmed the annual character of the baobab's growth rings. F14C values of tree-ring cellulose were found up to 8.8 % lower than in the corresponding atmospheric CO2 for the period around the ABP, which in conjunction with a considerable autocorrelation of the δ13C series points to the incorporation of previous year's carbon contributing to the average age of intra-ring wood samples. F14C of terminal parenchyma bands, marking the tree-ring boundaries, were found to be considerably younger than their corresponding tree ring, indicating that parenchyma tissue is alive for many years, probably undergoing cell division and structural reorganization and contributing to secondary growth. In contrast to the δ13C time series, no significant autocorrelation was found in the δ18O series of tree-ring cellulose despite the enormous water storage potential of this stem-succulent tree species. Year-to-year variability in tree-ring width and stable isotope ratios revealed radial stem growth and the geochemistry of wood cellulose are influenced by fluctuations in the hydroclimate. In particular, δ18O was found to be a good climate proxy, followed by tree-ring width and δ13C. Tree-ring width and intra-ring δ18Omin correlated well with each other and with precipitation amount for the period from pre-monsoon May to the end of the monsoon season in September/October. Intra-annual stable isotope courses were found to be rather similar for both δ13C and δ18O. Years with particularly low monsoon rain were reflected by increased stable isotope values in the mid-section of intra-annual courses. Distinct patterns with low subseasonal isotope values seem indicative for years with heavy rainfall events from pre-monsoonal cyclones. Rain events from post-monsoonal cyclones may also be recorded; however, only 2 years of observation prevented a more conclusive evaluation., Biogeosciences, 18 (12), ISSN:1726-4170

EGU General Assembly 2014, Vienna

Bisherige Verfahren zur Ertragsbestimmung von schnellwachsenden Baumarten im Kurzumtrieb sind entweder mit einem hohen Zeit- und Arbeitsaufwand verbunden und/oder haben destruktiven Charakter. Die vorliegende Arbeit beschäftigt sich mit der Entwicklung eines leicht anwendbaren, zerstörungsfreien und übertragbaren Ertragsschätzers für Kurzumtriebsbestände aus Pappel. Grundlage bildet die Standardisierung von Biomassefunktionen auf deren Basis ein standort- und klonunabhängiges Modell hergeleitet wird, das eine hinreichend genaue Schätzung des Biomassevorrates gestattet. Die Untersuchungen zu Grundlagen der Modellentwicklung und der Test verschiedener Modellansätze erfolgen auf der Basis von Korrelations- und Regressionsanalysen, Signifikanztests und Varianzanalysen. Die Prüfung der Schätzgenauigkeit basiert auf fünf Evaluierungskenngrößen. Für die Anwendung des klonunabhängigen, für Alter ≥ 3 Jahre und Bestandesdichten ≤ 25000 N/ha einsetzbaren Ertragsschätzers sind lediglich drei einfach und schnell zu erhebenden Ertragsgrößen (hm, N, dg) notwendig. Innerhalb der Modellgrenzen betragen die relativen maximalen Abweichungen zwischen Real- und Schätzwerten höchstens +/- 40 % und lässt sich der Biomassevorrat mit einer durchschnittlichen Differenz (Bias) von 7,1 % schätzen.