The quantification of disparity is an important aspect of recent macroevolutionary studies, and it is usually motivated by theoretical considerations about the pace of innovation and the filling of morphospace. In practice, varying protocols of data collection and analysis have rendered comparisons among studies difficult. The basic question remains, How sensitive is any given disparity signal to different aspects of sampling and data analysis? Here we explore this issue in the context of the radiation of the echinoid order Spatangoida during the Cretaceous. We compare patterns at the genus and species levels, with time subdivision into subepochs and into stages, and with morphological sampling based on landmarks, traditional morphometrics, and discrete characters. In terms of temporal scale, similarity of disparity pattern accrues despite a change in temporal resolution, and a general deceleration in morphological diversification is apparent. Different morphometric methods also produce similar signals. Both the landmark analysis and the discrete character analysis suggest relatively high early disparity, whereas the analysis based on traditional morphometrics records a much lower value. This difference appears to reflect primarily the measurement of different aspects of overall morphology. Disparity patterns are similar at both the genus and species levels. Moreover, inclusion or exclusion of the sister order Holasteroida and the stem group Disasteroida in the sampled morphospace did not affect proportional changes in spatangoid disparity. Similar results were found for spatangoid subclades vis-à-vis spatangoids as a whole. The relative robustness of these patterns implies that the choice of temporal scale, morphometric scheme, and taxonomic level may not affect broad trends in disparity and the representation of large-scale morphospace structure.

DIe Dissertationsschrift enthält mehrere teils in wissenschaftlichen Journals veröffentlichte Studien, die im Rahmen der kumulativen Dissertation entstanden. Im Fokus dieser Studien und der vorliegenden Dissertationsschrift steht die Untersuchung und Rekonstruktion Quartärer Umweltveränderungen in terrestrischen Ökosystemen. Dabei wurden Äolianit-paläobodensequenzen untersucht, anhand derer mithilfe von fossilen Gastropoden und deren stabilen Isotopensignalen Umweltinformationen abgeleitet werden.:TABLE OF CONTENT ACKNOWLEDGEMENT ABSTRACT KURZFASSUNG TABLE OF CONTENT 1 INTRODUCTION 1.1 RELEVANCE AND OBJECTIVE OF STUDYING FOSSIL GASTROPODS IN QUATERNARY DEPOSITS 1.2 MAJOR RESEARCH QUESTIONS AND METHODOLOGICAL APPROACH 1.3 STUDY SITES 1.4 REFERENCES 2 QUATERNARY GASTROPOD FAUNAS ON THE EASTERN CANARY ISLANDS AND INDICATIONS OF ENVIRONMENTAL CHANGES 2.1 INTRODUCTION 2.2 GEOGRAPHICAL SETTING 2.3 METHODS 2.4 RESULTS 2.5 DISCUSSION 2.6 CONCLUSIONS 2.7 ACKNOWLEDGEMENT 2.8 REFERENCES 2.9 SUPPLEMENTARY MATERIAL 3 QUATERNARY GASTROPOD FAUNAS IN SOUTHERN CAUCASIA AND INDICATIONS ON ENVIRONMENTAL CHANGES 3.1 INTRODUCTION 3.2 STUDY AREA 3.3 METHODS 3.4 RESULTS 3.5 DISCUSSION 3.6 CONCLUSION 3.7 ACKNOWLEDGEMENT REFERENCES 3.9 SUPPLEMENTARY MATERIAL 4 MALACOLOGICAL INVESTIGATIONS ON EASTERN CANARY SEDIMENT ARCHIVES –STABLE ISOTOPE INTERPRETATION IN AN OZEANIC SETTING 4.1 INTRODUCTION 4.2 GEOGRAPHICAL SETTING AND STATE OF KNOWLEDGE 4.3 METHODS 4.4 RESULTS 4.5 DISCUSSION 4.6 CONCLUSIONS 4.7 ACKNOWLEDGEMENT 4.8 REFERENCES 4.9 SUPPLEMENTARY MATERIAL 5 MALACOLOGICAL INVESTIGATIONS AT SOUTH CAUCASIAN SEDIMENT ARCHIVES –STABLE ISOTOPE INTERPRETATION IN A CONTINENTAL SETTING 5.1 INTRODUCTION 5.2 GEOGRAPHICAL SETTING AND STATE OF KNOWLEDGE 5.3 METHODS 5.3.1 Fieldwork 5.3.2 Laboratory Analyses 5.4 RESULTS 5.6 CONCLUSION 5.7 REFERENCES 5.8 SUPPLEMENTARY MATERIAL 6 SUMMARY AND SYNTHESIS 6.1 COMPARATIVE CONSIDERATION OF THE DIFFERENT SETTINGS 6.2 MAJOR CONCLUSIONS 6.3 PERSPECTIVE 6.4 REFERENCES

The presented study comprises a complete morphological and phylotaxonomic revision of basal Sphenacodontia, designated as the paraphyletic ‘haptodontines’. Ianthodon from the Kasimovian is known from newly identified elements, including most of the skull and particular postcrania. This species is determined as the best model for the initial morphology of the Sphenacomorpha (Edaphosauridae and Sphenacodontia). Remarkably older sphenacodontian remains from the Moscovian indicate a derived, though fragmentarily known form, possibly basal Sphenacodontoidea. The genus Haptodus is conclusively revised, including the revalidation of the type species H. baylei from the Artinskian. Haptodus grandis is renamed as Hypselohaptodus, gen. nov. “Haptodus” garnettensis is not monophyletic with Haptodus, moreover the material assigned to it yielded a greater diversity. Thus, its renaming includes Eohaptodus garnettensis, gen. nov., Tenuacaptor reiszi, gen. et spec. nov., and Kenomagnathus scotti, gen. et spec. nov. Along with Ianthodon and the basal edaphosaurid Ianthasaurus, these taxa from a single assemblage are differentiated by dentition and skull proportions, providing a case study of annidation. Since Ianthodon can be excluded from Sphenacomorpha, the larger, stem-based taxon Haptodontiformes is introduced. More derived ‘haptodontines’ apparently form another radiation, named as Pantherapsida. This new taxon includes Cutleria, Tetraceratops, Hypselohaptodus, the Palaeohatteriidae (Pantelosaurus and Palaeohatteria), and the Sphenacodontoidea. The ‘pelycosaur’-therapsid transition is affirmed as a long-term development. An integrative evolutionary hypothesis of basal sphenacodontians is provided, within which the ghost lineage of Early Permian therapsids can be explained by biome shift.:Chapter 1 ‘Haptodontines’ re-examined – An Introduction Chapter 2 New information on the cranial and postcranial anatomy of the early synapsid Ianthodon schultzei (Sphenacomorpha: Sphenacodontia), and its evolutionary significance Chapter 3 Reviewing the question of the oldest therapsid Chapter 4 Revision of the genus Haptodus (Synapsida: Haptodontiformes) and evolutionary implications from the Garnett fossil site Chapter 5 Morphological description and taxonomic status of Palaeohatteria and Pantelosaurus (Synapsida: Sphenacodontia) Chapter 6 Re-description of Cutleria and Tetraceratops (Synapsida, Sphenacodontia), with implications on the radiation of Sphenacodontoidea Chapter 7 Callibrachion and Datheosaurus, two historical and previously mistaken basal Caseasauria (Synapsida) from Europe Chapter 8 Synthesis and perspective

Technical complexities and the high cost of satellite images have hindered the adoption of remote sensing technology and tools for nature conservation works in Ethiopia as in many developing countries. The terrestrial and aquatic ecosystems in Abijjata Shala Lakes National Park (ASLNP) and the Important Bird Areas (IBAs) around the park are considered to be one of the most important home ranges for birds. However, little is known about the effect of land use/land cover (LULC) dynamics, due to lack of technical know how and logistical problems. However, it has been shown in this study that sophisticated image management works are not always relevant. Instead a simple method of utilizing the thermal band has been demonstrated. A new approach of long-term dynamics analysis method has also been suggested. A successful classification of images was achieved after such simple enhancement tests. It has been discovered that, there were more active LULC change processes in the area in the first study period (1973 to 1986) than during the second study period (1986-2000). In the first period nearly half of the landscape underwent land cover change processes with more than 26% of the entire landscape experiencing forest or land degradation. In the second period the extent of the change process was limited to only 1/3 of the total area with a smaller amount of degradation processes than before. During the entire study period, agriculture was responsible for the loss of more than 4/5 of the total terrestrial productive ecosystem. More than 37.6% of the total park area has been experiencing this loss for the past 3 decades. Only 1/5 of this area has a chance to revive, the remaining has undergone a permanent degradation. Lake Abijjata lost half of its size during the past 30 years. In the Zeway-Awassa basin 750 km², 2428km² and 3575km² of terrestrial lands and water bodies are within a distance of 10km, 20km and 30km from IBAs respectively. There are ecologically important areas where two or more IBAs overlap. In areas where more than two to five IBAs overlap, up to 85km² of areas have been recently degraded. High livestock density is one of the reasons for degradation. Using a monthly MODIS data from 2000-2005 and a series of interpolation techniques, the productivity of the area as well as the standing biomass were estimated. Moreover, a new method of spatially accurate livestock density assessment was developed in this study. Only 0.3% of the park area is found to be suitable for productive livestock development but nearly all inhabitants think the area is suitable. Feed availability in ASLNP is scarce even during rainy seasons. Especially the open woodlands are subject to overgrazing. Such shortage forces the inhabitants to cut trees for charcoal making to buy animal feed and non-food consumables. While more than 95% of the inhabitants in the park expanded their agriculture lands, only 13.3% of the farmers managed to produce cereals for market. The application of low cost remote sensing and GIS methods provided ample information that enables to conclude that low productivity and household food insecurity are the main driving forces behind land cover changes that are negatively affecting the natural and semi-natural ecosystems in the central and southern Rift Valley of Ethiopia. The restoration of natural ecosystems or conservation of biodiversity can be achieved only if those driving forces are tackled sustainably.

Diese Arbeit beinhaltet experimentelle und theoretische Untersuchungen der optischen Frequenzverdopplung (second-harmonic generation, kurz SHG) an metallischen Nanopartikeln. Frequenzverdopplung bedeutet, daß ein bei der Frequenz omega angeregtes Nanopartikel Strahlung der Frequenz 2*omega emittiert. Dieser Effekt tritt nicht nur in Materialien mit nichtzentrosymmetrischer Kristallstruktur, sondern auch an der Oberfläche von Metallen auf. Deshalb läßt er sich gut mit plasmonischen Feldüberhöhungen an metallischen Nanoantennen verbinden. Die Frequenzverdopplung wird an verschiedenen Nanostrukturen wie dreieckförmigen, stäbchenförmigen und vor allem kegelförmigen Nanopartikeln experimentell untersucht, welche aufgrund ihrer scharfen Spitzen starke SHG-Signale emittieren. Besonders die Kegel sind interessant: Bei Anregung mit einem fokussierten, radial polarisierten Strahl dominiert je nach Kegelgröße und Umgebungsmedium ein SHG-Signal entweder von der Spitze oder von der Bodenkante des Kegels. Diese an den Kegeln gemessenen Resultate werden durch theoretische Untersuchungen untermauert. In diesen Rechnungen werden die plasmonischen Feldüberhöhungen und die sich daraus ergebende Frequenzverdopplung für einen Kegel mit verschiedenen Parametern modelliert. An einem einzelnen Kegel gewonnene Resultate werden auch mit den Fällen eines kugelförmigen und eines stäbchenförmigen Partikels verglichen. Ein weiterer Gegenstand der theoretischen Untersuchungen ist die Superposition der zweiten Harmonischen von mehreren emittierenden Nanopartikeln zu einem Feldmaximum. Dabei wird eine kreisförmige Anordnung von 8 Nanostäbchen bzw. Nanokegeln von einer radial polarisierten Mode angeregt. Die Superposition der emittierten zweiten Harmonischen ergibt ein Feldmaximum innerhalb der Anordnung der Emitter. Durch eine Verkippung des anregenden Strahls kann dieser Fokus im Raum bewegt werden. Letztere Untersuchung ist insbesondere interessant im Hinblick auf lokalisierte photochemische Reaktionen, die durch das frequenzverdoppelte Licht von Nanopartikeln ausgelöst werden sollen. Mit chemischen Substanzen, die bei omega transparent, bei 2*omega aber photoreaktiv sind, wäre im Nahfeld dieser Nanoantennen eine starke Lokalisierung der Reaktion auf Bereiche kleiner als 100~nm möglich. Anhand von Photolacken und Polymermatrizen mit diesen Eigenschaften wird experimentell untersucht, ob frequenzverdoppeltes Licht überhaupt solche Reaktionen auslösen kann oder ob die photochemische Reaktionen überwiegend durch direkte Zwei-Photonen-Absorption des anregenden Lichts ausgelöst werden. Die Ergebnisse zeigen allerdings, daß die Zwei-Photonen-Absorption dominant ist. Durch die Zwei-Photonen-Absorption im Nahfeld von Partikeln ist aber dennoch eine vergleichbare Lokalisierung der Reaktion möglich.:1. Einführung 1.1 Frequenzverdopplung an Nanopartikeln 1.2 Photochemisches Schreiben auf kleinen Längenskalen 2. Theoretische Grundlagen 2.1 Nichtlineare optische Effffekte zweiter Ordnung 2.2 Frequenzverdopplung in Metallen 2.3 Frequenzverdopplung bei metallischen Nanopartikeln 2.4 Überlagerung der Strahlung mehrerer frequenzverdoppelter Dipole 2.5 Core-Shell-Nanopartikel mit nichtzentrosymmetrischem Kern 3. Experimenteller Aufbau 3.1 Beleuchtung der Proben und Detektionspfad 3.2 Objektiv und Probenhalter 3.3 Realisierung der radial polarisierten Mode 4. Messungen der zweiten Harmonischen an Nanostrukturen 4.1 Einzelne kugel- und stäbchenförmige Goldnanopartikel 4.2 Nanodreiecke (Fischer-Pattern) 4.3 Nanokegel 4.4 Nanostäbchen-Teppiche 4.5 Zusammenfassung 5. Nichtlinear-optisches photochemisches Schreiben auf kleinen Längenskalen 5.1 Photochemische Reaktionen auf der Sub-100nm-Skala 5.2 Erste Versuche an Photolacken 5.3 Photochemisches Schreiben auf azobenzolhaltigen PMMA-Copolymerschichten 5.4 Photochemisches Schreiben auf azosulfonathaltigen PMMA-Copolymerschichten 5.5 Ausblick 6. Zusammenfassung und Ausblick Anhang A. Darstellung der radialen Mode und des z-polarisierten Fokus B. Mehode der multiplen Multipole (MMP) C. Präparation der Proben Literaturverzeichnis Abbildungsverzeichnis Verzeichnis der Tabellen Verwendete Abkürzungen Liste der Veröffffentlichungen Danksagung Erklärung / This work includes experimental and theoretical investigations of second-harmonic generation (SHG) at metallic nanoparticles. SHG means that a nanoparticle that is excited at the frequency omega emits radiation at the frequency 2*omega. SHG does not only occur in materials with noncentrosymmetric structure, but also on metal surfaces. Hence, SHG can be combined well with plasmonic field enhancement at metallic nanoantennae. SHG is investigated experimentally at different nanostructures such as triangle-like, rod-like and especially cone-like nanoparticles. With their sharp tips these structures show a much stronger SHG signal than spherical nanoparticles. Especially the cones are interesting: Excited with a focused radially polarized beam, for different cone sizes and in different surrounding media either the signal from the tip or the signal from the bottom edge dominates. The measurement results from the cones are underpinned by theoretical investigations. In these calculations the plasmonic field enhancements and the resulting SHG are modeled for a cone with different parameters. The single-cone results are also compared with the cases of a spherical or rod-shaped particle. A further subject of the theoretical investigations is the superposition of the SHG radiation from a number of emitting nanoparticles to a field maximum. For that, a circular arrangement of 8 nanorods or nanocones is excited by a radially polarized beam. The superposition of the second-harmonic radiation fields yields a field maximum in the space between the emitters. A tilt of the exciting beam can move this focus in space. The latter item is of special interest concerning localised photochemical reactions induced by the second-harmonic light from nanoparticles. In the near field of these nanoantennae, a strong localisation of the reaction on regions smaller than 100 nm would be possible by using chemical substances being transparent at omega, but photoreactive at 2*omega. With photoresists and polymer matrices, experiments are carried out to investigate whether SHG light can trigger such reactions at all, or if these photochemical reactions are triggered predominantly by direct two-photon absorption of the exciting light. The results show that the two-photon absorption is the dominant process. Yet, through two-photon absorption in the near field of particles, the localisation of the reaction is still similar.:1. Einführung 1.1 Frequenzverdopplung an Nanopartikeln 1.2 Photochemisches Schreiben auf kleinen Längenskalen 2. Theoretische Grundlagen 2.1 Nichtlineare optische Effffekte zweiter Ordnung 2.2 Frequenzverdopplung in Metallen 2.3 Frequenzverdopplung bei metallischen Nanopartikeln 2.4 Überlagerung der Strahlung mehrerer frequenzverdoppelter Dipole 2.5 Core-Shell-Nanopartikel mit nichtzentrosymmetrischem Kern 3. Experimenteller Aufbau 3.1 Beleuchtung der Proben und Detektionspfad 3.2 Objektiv und Probenhalter 3.3 Realisierung der radial polarisierten Mode 4. Messungen der zweiten Harmonischen an Nanostrukturen 4.1 Einzelne kugel- und stäbchenförmige Goldnanopartikel 4.2 Nanodreiecke (Fischer-Pattern) 4.3 Nanokegel 4.4 Nanostäbchen-Teppiche 4.5 Zusammenfassung 5. Nichtlinear-optisches photochemisches Schreiben auf kleinen Längenskalen 5.1 Photochemische Reaktionen auf der Sub-100nm-Skala 5.2 Erste Versuche an Photolacken 5.3 Photochemisches Schreiben auf azobenzolhaltigen PMMA-Copolymerschichten 5.4 Photochemisches Schreiben auf azosulfonathaltigen PMMA-Copolymerschichten 5.5 Ausblick 6. Zusammenfassung und Ausblick Anhang A. Darstellung der radialen Mode und des z-polarisierten Fokus B. Mehode der multiplen Multipole (MMP) C. Präparation der Proben Literaturverzeichnis Abbildungsverzeichnis Verzeichnis der Tabellen Verwendete Abkürzungen Liste der Veröffffentlichungen Danksagung Erklärung