Mourasuchus (Alligatoroidea, Caimaninae) é um táxon extinto de crocodilianos restrito ao Cenozoico da América do Sul. Representa um dos grupos de crocodilianos mais peculiares de todos os tempos, devido ao formato longo, largo e achatado de seu rostro (lembrando o bico de um pato) entre outras características. Apesar dessas peculiaridades, relativamente poucos trabalhos foram feitos sobre esse grupo. A maioria das descrições morfológicas dos fósseis do gênero são sucintas e breves, incluindo as dos holótipos de duas das quatro espécies a ele assinaladas: M. amazonensis e M. arendsi. Do mesmo modo, as diagnoses das quatro espécies também se mostram sucintas. Poucas também são as análises filogenéticas realizadas com Mourasuchus a maioria das quais, porém, recupera Orthogenysuchus olseni, do Eoceno dos Estados Unidos, como táxon-irmão de Mourasuchus, gerando um impasse biogeográfico. Além disso, a maneira exata pela qual Mourasuchus se alimentava, fazendo uso de seu peculiar rostro bico de pato, bem como seus itens alimentares, ainda não foram plenamente esclarecidos, ainda que algumas teorias tenham sido propostas na literatura. Assim, este trabalho se propôs a: oferecer uma re-descrição dos holótipos de M. amazonensis e M. arendsi; revisar as diagnoses das espécies e do próprio gênero; realizar uma análise filogenética investigando as relações das espécies entre si e do gênero, como um todo, em Caimaninae; investigar a relação de Orthogenysuchus olseni como táxon-irmão de Mourasuchus; elucidar o modo de forrageio e os itens alimentares consumidos pelo grupo. As re-análises das diagnoses das espécies revelaram que duas delas constituem, na verdade, espécies não-válidas, enquanto a análise de um novo material craniano descrito neste trabalho (MCNC-PAL-110-72V) revelou a existência de uma nova espécie de Mourasuchus, fazendo com que este trabalho reconheça três espécies válidas para o gênero. A análise filogenética revelou M. atopus como o táxon mais basal, enquanto M. amazonensis e a nova espécie proposta formam um clado mais derivado. Orthogenysuchus olseni não foi recuperado como táxon-irmão de Mourasuchus em nenhuma das análises, mas seu posicionamento ainda dentro de Caimaninae faz com que impasses biogeográficos permaneçam. Este trabalho defende que Mourasuchus coletava presas em grande quantidade usando a musculatura da parte de baixo de seu rostro uma alimentação coletora enquanto ainda não há evidências de que esses animais fariam uma filtração da massa alimentar coletada. É possível, também, que tal hábito tenha evoluído a partir do hábito alimentar durófago exibido por Caimaninae basais, especialmente o gênero Gnatosuchus. / Mourasuchus (Alligatoroidea, Caimaninae) is an extinct crocodilian taxon restricted to the Cenozoic of South America. It represents one of the most peculiar crocodilian groups of all time, due to the long, wide, flattened shape of its rostrum (resembling the beak of a duck), among other features. Regardless these peculiarities, relatively few works have been done about this group. Most of morphological descriptions of the fossils belonging to this genus are shot and brief, including those of two from the four species assigned to it: M. amazonensis and M. arendsi. Similarly, the diagnoses of all the four species are also very brief. The phylogenetic analyses involving Mourasuchus are also very few most of them, however, recover Orthogenysuchus olseni, from the Eocene of the United States, as Mourasuchus sister-taxon, creating a biogeographically problematic scenario. Furthermore, the exact way by which Mourasuchus feed itself, using its peculiar beak of duck rostrum, as well as its prey items, are yet to be determined, even though some proposals have already been made in the literature. As such, this work had the following objectives: offer a redescription of the holotypes of M. amazonensis and M. arendsi; re-evaluate the diagnoses of Mourasuchus species and the genus itself; perform a phylogenetic analysis to evaluate the relationships between Mourasuchus species and of this group, as a whole, within Caimaninae; evaluate the position of Orthogenysuchus olseni as a sister-taxon of Mourasuchus; elucidate the foraging tactics and the prey items consumed by this group. The re-evaluation of the diagnoses of the species revealed that two are in reality non-valid species, while the analysis of a new cranial material described in this work (MCNC-PAL-110-72V) revealed the existence of a new species of Mourasuchus, taking this work to recognize the existence of three valid species for the genus. The phylogenetic analysis recovered M. atopus as the basalmost taxon, while M. amazonensis and the new species proposed in this work form a more derived clade. Orthogenysuchus olseni was not recovered as a Mourasuchus sister-taxon in any of the analyses made, but its position still within Caimaninae maintains biogeographically problematic scenarios in this clade. This work defends that Mourasuchus collected a high number of prey items using the musculature between the lower jaws a collecting foraging tactic while there is still no evidence that these animals could perform a straining of the entire concentration of food it collected. It is possible, as well, that such habit may have evolved from the durophagous feeding habit of some basal Caimaninae, especially Gnatosuchus.

The Friis Hills is an isolated plateau standing as much as 600 m above surrounding topography in the McMurdo Dry Valleys region or Antarctica.Preserved on the plateau surface is a sequence of early to middle Miocene-aged dritis. At the eastern edge of the plateau, these drifts fill a shallow paleovalley to a depth of at least 35 m. The drills are exposed in a natural cross-section where modern topography crosscuts the paleovalley. Establishing an age and an environmental interpretation for these deposits is important because Antarctic paleoclimate records are lacking from the Mid-Miocene Climate Optimum. Two drifts fill the ancient paleovalley in the eastern Friis Hills. The upper drift is here named Cavendish drift: the lower is here named Friis drift. Cavendish can be subdivided into three units, whereas Friis drift can be subdivided into two units. Each of these units is a horizontal bed that laps on paleovalley sidewalls. The lowest, Friis II, is a compact diamicton that is overlain by a nearly in-situ bedded volvanic ash. Based on [20]Ar/[39]Ar dating, the ash is 19.76 [plus/minus] 0.07 Ma old. A second diamicton, Friis I, conformably blankets Friis II and was discovered to hold fossileferous interbeds. Both Friis I and II contain erratic clasts and both are lodgemont tills deposited from small, locally derived, alpine glaciers. Bedrock striations show ice flow to the northeast at azimuths between 025? to 032?, parallel to the trend of the paleovalley axis. Above these, Cavendish I. II. and III were deposited when thick ice covered the Friis Hills. Where the Cavendish drift laps onto paleovalley sidewalls, bedrock striations show ice flow from 077? to 150?. Cavendish drift was deposited sometime alter 19.8 Ma but before 14 Ma. when the Dry Valleys glacial records show that regional glaciers became cold-based. Downcutting eventually isolated the Friis Hills plateau, resulting in the preservation of the drift sequence. This event was most likely associated with growth or the East Antarctic Ice Sheet 14 Ma ago. This age constraint means that the tills preserved in the Friis Hills date from a time just before the East Antarctic Ice Sheet expanded and became a permanent feature. Based on the age-dated stratigraphy presented in this thesis, future work focusing on fossiliferious interbeds could provide unique and important constraints on Miocene climate change. / North Dakota State University. Department of Geosciences

The thesis presents systematical study and taphonomical evaluation of fusite wood specimens collected in the middle bench of the main lignite seam in the Bilina mine. In the introduction part, there are a general characteristic of the Most Basin and its geological setting with respect to the main lignite seam. Consequently, the charcoal is described in detail. Generally, the charcoaled wood, which was produced during wildfires in the Tertiary forests, shows well preserved anatomical details. The final part resumes systematics and taphonomy of the charcoal specimens collected by the author.

In the Most Basin, there is a rich variety of plant macrofossils, whose findings are described for the first time already in the 19th century. The presented thesis is focused on conifer wood preserved as xylitic stumps in situ. The samples come from the so-called "stumpy horizont No. 31" situated in the roof of the main lignite seam in the Bílina Mine. A detailed xylotomical study with scanning electron microscopy allows their assignment to the Cupressaceae s.l., to the morphospecies Glyptostroboxylon rudolphii and Taxodioxylon gypsaceum.

Beavers are members of Castoridae - the family of large rodents characterized by a robust skull of sciuromorphic type, a sciurognathous mandible, dentition with a tendency to hypsodoncy and incisives by uniserial microstructure. The aim of the thesis is a detailed morphometric analysis of the fossil material of beavers coming from the early Miocene (MN 3a) locality Ahníkov I, II in the Czech Republic. In the numerous material comprising 388 fragmentary specimens, all belonging to the genus Steneofiber, two distinct species were distinguished, attributed here as - Steneofiber eseri (the larger form) and Steneofiber aff. dehmi (the smaller form). Their taxonomy, systematics and assumed position within existing phylogenetic models were discussed. Key words: Castoridae, Steneofiber, Czech republic, Ahníkov, MN 3, early Miocene

This thesis deals with the use of geochemical proxies on foraminifera for paleoceanographical, paleoecological and paleoenvironmental interpretations in the fossil epicontinental sea - the Central Paratethys during the Langhian. It discusses the used methodologies and approaches that were specially chosen to fit the problematic of the studied area such as the single test analysis of carbon and oxygen stable isotopes on foraminifera. Other geochemical methods were represented by Mg/Ca based paleothermomethry and by several organic geochemistry proxies on whole rock samples (n-alkane indices, δ13 Corg, and carbon ratios - TOC/TIC/TC). These were further combined with foraminiferal paleoecological data, which allowed identification of particular water masses in the studied region as well as the prevailing circulation patterns/regimes during the studied interval in the Paratethyan marine realm. Additionally, there were interpreted various regional paleoenvironmental and paleoecological consequences. The Paratethys had similar hydrography of surficial waters with the Mediterranean, conversely to the bottom waters that were different, probably of a regional origin with their own evolution during the studied time interval. The anti-estuarine circulation regime, which was probably linked with the closure...

Water availability in the ecosystem is one of the most crucial environmental factors that determines global terrestrial biome distribution. However, aridity/humidity conditions in the geologic past are difficult to quantify, mainly owing to the lack of a proper parameter. By using modern global climatic data, we here examine five selected previously proposed aridity indices (AIs), in which the climatic variables involved, including both precipitation and temperature, are simple and likely available in studies of paleoclimatology and paleoecology, although with different degrees of uncertainty. They were first evaluated along the modern climatic zones of eastern China, with the main metric of Thornthwaite humidity index (HI) and with the supplementary reference of soil moisture index (SMI) and near-ground atmospheric relative humidity (RH). Then AIs and the mean annual precipitation (MAP) were further statistically compared with HI, SMI, and RH, respectively, based on 1189 monitored data sets from meteorological stations over the world. The results show that the Köppen aridity index (AIKöppen), expressed as mean annual precipitation divided by mean annual temperature plus a constant of 33, is the most accurate and precise index among all selected indices, supported by the highest correlation coefficient respectively to HI, SMI, and RH, three widely-employed major indicators sensitive to hydrological dynamics in climatology and meteorology. Specifically, AIKöppen does well mirror corresponding HI along four representative transects from North America, South America, Africa, and Australia, which cover the typical arid and humid climates and span the main terrestrial biome types. Moreover, our results also distinctly reveal that, as also shown by many studies on modern climate, precipitation alone is inadequate to measure the hydrological condition, because both temperature and evapotranspiration are two other critical factors that strongly influence water balance in the ecosystem, meanwhile evapotranspiration is mainly affected by temperature. Based on the validated AIKöppen, we briefly discuss the aridity/humidity condition in China during the middle Miocene. The results demonstrate that moisture did decrease westward, but it is also clear that western China in the middle Miocene appears not to have been as dry as previously thought, indicated by the AIKöppen values representing a sub-humid to humid climate.

Water availability in the ecosystem is one of the most crucial environmental factors that determines global terrestrial biome distribution. However, aridity/humidity conditions in the geologic past are difficult to quantify, mainly owing to the lack of a proper parameter. By using modern global climatic data, we here examine five selected previously proposed aridity indices (AIs), in which the climatic variables involved, including both precipitation and temperature, are simple and likely available in studies of paleoclimatology and paleoecology, although with different degrees of uncertainty. They were first evaluated along the modern climatic zones of eastern China, with the main metric of Thornthwaite humidity index (HI) and with the supplementary reference of soil moisture index (SMI) and near-ground atmospheric relative humidity (RH). Then AIs and the mean annual precipitation (MAP) were further statistically compared with HI, SMI, and RH, respectively, based on 1189 monitored data sets from meteorological stations over the world. The results show that the Köppen aridity index (AIKöppen), expressed as mean annual precipitation divided by mean annual temperature plus a constant of 33, is the most accurate and precise index among all selected indices, supported by the highest correlation coefficient respectively to HI, SMI, and RH, three widely-employed major indicators sensitive to hydrological dynamics in climatology and meteorology. Specifically, AIKöppen does well mirror corresponding HI along four representative transects from North America, South America, Africa, and Australia, which cover the typical arid and humid climates and span the main terrestrial biome types. Moreover, our results also distinctly reveal that, as also shown by many studies on modern climate, precipitation alone is inadequate to measure the hydrological condition, because both temperature and evapotranspiration are two other critical factors that strongly influence water balance in the ecosystem, meanwhile evapotranspiration is mainly affected by temperature. Based on the validated AIKöppen, we briefly discuss the aridity/humidity condition in China during the middle Miocene. The results demonstrate that moisture did decrease westward, but it is also clear that western China in the middle Miocene appears not to have been as dry as previously thought, indicated by the AIKöppen values representing a sub-humid to humid climate.

Fossil fruits including nuts and associated husk valves of a new species of Carya (Juglandaceae) are described from the latest Miocene to earliest Pliocene in northeastern Tennessee, eastern United States. The husk valves are elliptic, 1.2-4.5mm thick, with a convex exterior face and a concave interior face; the nuts are globose to ovoid in shape, smooth and longitudinally ribbed on exterior surface, with a short protruding apex and a slightly 4-angled base; inner ribs, lacunae and primary septa are well-developed, while secondary septa are absent or weakly developed. The combination of these carpological characteristics clearly shows a close resemblance to the genus Carya in Juglandaceae. Detailed comparisons of carpological morphology and anatomy indicate that the present fossil taxon is different from both living and most other fossil species of the genus, and therefore warrants the designation of a new fossil species, Carya tennesseensis Huang et al., sp. nov. Carya tennesseensis displays a carpological similarity to C. ventricosa from the late Oligocene to early Pliocene in Europe, suggesting a potential species exchange of the genus between Europe and southeastern North America during the late Neogene. The new fossil species represents one of the few fruit fossil species of Carya from its modern distribution range in southeastern North America. It provides crucial information for better understanding the rapid diversification of the genus from the late Miocene to early Pliocene, and the origin and establishment of today's Carya biodiversity in this region.

The late Miocene Xianfeng flora of Yunnan Province, southwestern China, was chosen to reconstruct the paleoclimate and the intensity of the Asian monsoon. Three available quantitative climate reconstruction methods from fossil plants, i.e. Leaf Margin Analysis (LMA), the Climate Leaf Analysis Multivariate Program (CLAMP), and the Coexistence Approach (CA) were used in this study. MATs (mean annual temperatures) resulting from these three approaches (i.e., LMA: 17.2 ± 2.38°C; CLAMP: 15.43 ± 1.25°C; CA: 17.2-21.7°C) appear to have been higher than the present (14.9°C), suggesting a much warmer climate in the late Miocene. Both the growing season precipitation (GSP) from CLAMP (1908.7 ± 217.7. mm) and mean annual precipitation (MAP) from CA (1206.0-1613.0. mm) estimates are higher than modern values (1003.2. mm (GSP) and 1038. mm (MAP) respectively) indicating a more humid climate during the late Miocene. By comparing these with climates reconstructed from neighboring late Miocene floras, we conclude that the general late Miocene climate appears warmer and more humid than present conditions in southwestern China. Furthermore, the evident differences in estimated monthly temperatures between the summer and winter, and precipitations between the humid and dry seasons indicate the existence of seasonality, though not as strong as that of today. Difference in precipitation of dry season indicates a marked strengthening in the winter monsoon since the late Miocene. A new monsoon intensity index has also been defined based on precipitation seasonality to investigate the intensity of the Asian monsoon.