No description available.

Conserving biodiversity in the current global ecological crisis requires a robust understanding of a multitude of abiotic and biotic processes operating at spatial and temporal scales that are nearly impossible to study on a human timescale and are therefore poorly understood. However, fossil data preserve a vast archive of information on past ecosystems and how they have changed through time. My PhD research is composed of three studies that look at biogeogaphic distribution, ecosystem structure, and trends in richness and diversity. Identifying organisms to the species level is a common practice in ecology when conducting community analyses. However, when species-level identification is not feasible, higher level taxonomic identifications are used as surrogates. This study tests the validity of supraspecific identifications for vertebrates in regional biogeography studies, using the recorded occurrences of terrestrial and aquatic taxa from 16 national parks on the Colorado Plateau and culling the data set based on a series of taphonomic processes to generated fossil assemblages. Changes in community structure as a result of increased magnitude and/or frequency of perturbations have been well documented in terrestrial and marine ecosystems. Unfortunately, the long-term effects of sea-level rise on vertebrate communities in coastal habitats are poorly understood and difficult to study on a human time scale. This study examines the long term effects of relative sea-level change on coastal plain ecosystems of the Belly River Group (Campanian) in southern Alberta using microvertebrate fossils. Most Cretaceous freshwater deposits in North America produce only a couple of articulated fish skeletons. Because of this preservational bias many workers suggested that freshwater teleosts were largely absent from North America until the Eocene or later. Late Cretaceous fish assemblages are of particular interest, because these assemblages undergo a major compositional change. Pre-Cretaceous fish assemblages are dominated by non-teleosts, while Paleogene assemblages are dominated by teleosts that are members of extant families. This study provides a first approach in characterizing long-term trends in richness and the distribution of Late Cretaceous, nonmarine actinopterygians of the Western Interior of North America.

No description available.

No description available.

In central Anatolia, Turkey, a strand of the former northern Neotethys Ocean subducted northwards under the Eurasian (Pontide) active margin during Late Cretaceous–Early Cenozoic time. Subduction and regional plate convergence were associated with the generation and emplacement of accretionary complexes and supra-subduction zone-type ophiolites onto former passive margins of microcontinents. The resultant suture zones contain Late Cretaceous to Middle Eocene basins (“The Central Anatolian Basins”) including: 1) the Kırıkkale Basin; 2) the Çankırı Basin, 3) the Tuz Gölü Basin and; 4) the Haymana - Polatlı Basin. Using stratigraphic logging, igneous geochemistry, micropalaeontology and provenance studies, this study tests two end-member models of basin evolution. In model one, the basins developed on obducted ophiolitic nappes following closure of a single northern Neotethys Ocean during the latest Cretaceous. In model two, northern Neotethys comprised two oceanic strands, the İzmir-Ankara-Erzincan Ocean to the north and the Inner Tauride Ocean to the south, separated by the Niğde-Kırşehir microcontinent, which was rifted from the Gondwana continent to the south. In this scenario, the basins developed as accretionary-type basins, associated with north-dipping subduction which persisted until the Middle Eocene when continental collision occurred. Where exposed, the basements of the Central Anatolian Basins comprise the Ankara Mélange, a mainly Upper Cretaceous subduction-accretion complex and the western/northern margin of the Niğde-Kırşehir microcontinent. New geochemical data from the composite basement of the Kırıkkale Basin identify mid ocean-ridge basalt (MORB), here interpreted to represent relict Upper Cretaceous Neotethyan oceanic crust. During the latest Cretaceous, the Kırıkkale and Tuz Gölü Basins initiated in deep water above relict MORB crust and ophiolitic mélange, bordered by the Niğde-Kırşehir microcontinent to the east where marginal facies accumulated. Further west, the Haymana-Polatlı Basin represents an accretionary-type basin constructed on the Ankara Mélange. To the north, the Çankırı Basin developed on accretionary mélange, bounded by the Pontide active margin to the north. Palaeocene sedimentation was dominated by marginal coralgal reef facies and siliciclastic turbidites. Latest Palaeocene–middle Eocene facies include shelf-type Nummulitid limestone, shallow-marine deltaic pebbly sandstones and siliciclastic turbidites. This thesis proposes a new model in which two north-dipping subduction zones were active during the late Mesozoic within northern Neotethys. In the south, ophiolites formed above a subduction zone consuming the Inner Tauride Ocean until the southward retreating trench collided with the northern margin of the Tauride continent emplacing ophiolites and mélange. In the north, subduction initiated outboard of the Eurasian margin triggering the genesis of supra-subduction zone ophiolites; the subduction zone rolled back southwards until it collided with the Niğde-Kırşehir microcontinent, again emplacing ophiolites during latest Cretaceous time. Neotethyan MORB still remained to the west of the Niğde-Kırşehir microcontinent forming the basement of the Kırıkkale and Tuz Gölü Basins. Latest Palaeocene–middle Eocene regional convergence culminated in crustal thickening, folding, uplift and strike-slip faulting which represent final continental collision and the geotectonic assembly of central Anatolia.

The research reported in this thesis focuses on Late Cretaceous and Cenozoic fossil brachiopods of Western Australia. Although the work is primarily taxonomic, it also includes biodiversity, distribution and some aspects of ecology of the brachiopods described.The most recent information on the anatomy, physiology and ecology of brachiopods is summarised at the beginning of the thesis.Identification of brachiopods is determined primarily on internal morphological features as brachiopods tend to be homomorphic, many species looking externally the same. The morphological features used in the identification of the brachiopods described within the thesis are defined.The fossil material studied has come from four sedimentary basins in Western Australia. The Carnarvon Basin contains Late Cretaceous and Cenozoic fossil material. The Perth Basin also has Late Cretaceous and late Cenozoic brachiopods The Bremer and Eucla Basin have Cenozoic deposits. The stratigraphy of the deposits containing the brachiopods is described.Until this study commenced, eight species had been described from Western Australia. This thesis describes fifty eight species including thirty new species, one new family and two new genera.In preparing descriptions of the new species it become evident that many of the species from the Southern Hemisphere were quite different to those found in the Northern Hemisphere. Their closest affiliation was with genera and species described from the Antarctic Peninsula. Four genera and one species from the Late Cretaceous deposits of Western Australia are common to the Late Cretaceous deposits of the Antarctic Peninsula. In the examination of the Tertiary material from the Carnarvon Basin, it also became clear that there was a strong correlation with Tertiary material from the Antarctic Peninsula. At least four genera are common to both deposits. Six brachiopod ++ / genera from the Middle Miocene deposits of the South Shetland Islands Antarctica are common to New Zealand. Nine genera, identified from the La Meseta Formation, Seymour Island, Antarctic Peninsula, are also common to New Zealand. These genera are also found in Australia. This evidence has led to the proposal that in the Late Cretaceous there was a common shelf environment from the Antarctic Peninsula to the north-west coast of Western Australia. In this area, which formed the high latitude southern circum-Indo-Atlantic faunal province, brachiopods evolved different genera and species than those in the northern hemisphere. Many then dispersed into northern areas of the Indian, Atlantic and finally Pacific Oceans.When the material from the Middle to Late Eocene of the Bremer and Eucla Basin was examined, five genera were found to be common to the Early Tertiary of the Carnarvon Basin. When comparing the species from the south-western basins and those from the south- east it was evident that similar species occur in the Middle to Late Eocene of the Bremer, Eucla, St Vincent and Murray Basins. There are some fifteen species in common. Many of these species then occur in the Late Oligocene south-eastern basins near Victoria and Tasmania as the gap between the Australia mainland and Tasmania began to open. One species that occurs in the Late Eocene of Western Australia is also described from the Late Oligocene of New Zealand.In considering the distribution of the Cenozoic brachiopods, genera first appear in the north-west of Western Australia and they then appear in chronological order in the south-western basins and south-eastern basins of South Australia, then the south-eastern basins of Victoria and Tasmania and then New Zealand. By the Late Eocene, there was a shallow marine connection between the Bight and the Tasman Sea. By the Late Oligocene this had widened and ++ / Australia was finally totally separated from Antarctica.The Proto-Leeuwin Current was responsible for the distribution of the brachiopods from the north-west of Western Australia to the southern coast. Possible mechanisms for the distribution of genera to New Zealand include rafting and an extended larval stage.It has been suggested that brachiopods in Australia are distributed according to the substrate on which they settle rather than any other factor. Using the information on the distribution of brachiopods in Western Australia throughout the Cenozoic this hypothesis is examined. It is suggested that avoidance of light in the photic zone and food availability with competition with bivalves are more important factors than substrate conditions.

Le dinosaure ornithopode Rhabdodon a été nommé par Matheron en 1869 et la première espèce,Rhabdodon priscus, a été proposée sur la base d'un fragment dentaire avec ses dents très caractéristiquesdécouvert dans le Crétacé supérieur des Bouches-du-Rhône dans le Sud de la France. Une nouvelle espèce, R.septimanicus., a ensuite été proposée par Buffetaut et Le Loeuff en 1991 sur la base d’un dentaire trouvé dansune localité du Crétacé supérieur à Montouliers (Hérault). La validité de cette nouvelle espèce était en débat, laquestion étant de savoir combien d'espèces de Rhabdodon existaient dans le Sud de la France. Un abondantmatériel inédit (crânien et postcrânien) de Rhabdodon, découvert récemment au cours de fouilles sur diverssites du Sud de la France, est décrit, de sorte que l’'anatomie de cet animal est désormais mieux connue. Unereconstitution de Rhabdodon est proposée. R. septimanicus est considéré comme valide à la suite de l'inclusionde nouveaux éléments crâniens de Quarante (Hérault). Deux espèces de Rhabdodon ont certainement coexistédurant le même période (Campanien supérieur – Maastrichtien inférieur) dans le Sud de la France. L'analysephylogénétique confirme que Rhabdodon peut être placé dans une famille des Rhabdodontidae avec son taxonfrère,Zalmoxes, dont il se distingue par de nombreux caractères postcrâniens. Les Rhabdodontidae sontproches des Iguanodontia. Il est suggéré que l'ancêtre commun des rhabdodontidés a évolué en Amérique duNord, puis s’est dispersé en Europe et a finalement évolué dans l'isolement géographique de l’archipeleuropéen au cours de du Crétacé supérieur. / The ornithopod dinosaur Rhabdodon was named by Matheron in 1869 and a first species,Rhabdodon priscus, was proposed on the basis of a dentary fragment with its diagnostic teeth from the LateCretaceous of Bouches-du-Rhône in southern France. A new species, R. septimanicus, was subsequentlyerected by Buffetaut and Le Loeuff (1991) based on a characteristic dentary from a Late Cretaceous locality atMontouliers (Hérault). The validity of the latter species was in debate, the question being how many species ofRhabdodon existed in Southern France. Abundant unpublished material (both cranial and postcranial) ofRhabdodon discovered in recent excavations at various localities in southern France is described, as a result ofwhich the anatomy of this animal is now better known. A reconstruction of Rhabdodon is proposed. R.septimanicus is considered as valid by including new cranial elements from Quarante (Hérault). Two species ofRhabdodon undoubtedly coexisted in the same time interval (Late Campanian – Early Maastrichtian) insouthern France. The phylogenetic analysis confirms that Rhabdodon can be placed in a distinct family,Rhabdodontidae, which also includes its sister taxon, Zalmoxes, from which it is distinguished by numerouspostcranial characters. Rhabdodontidae has a close relation with Iguanodontia. It is suggested that the commonancestor of the rhabdodontid dinosaurs evolved in North America, and then dispersed to Europe and eventuallyevolved in geographical isolation on the various European landmasses during the Late Cretaceous.

A região de General Salgado (Formação Adamantina, Bacia Bauru) mostra-se como uma região extremamente rica em fósseis de vertebrados. Essa riqueza evidencia-se na presença de diversos registros de Crocodilianos do Cretáceo. Entre eles, encontra-se um esqueleto articulado, composto por partes do crânio e um pó-crânio praticamente completo. Os caracteres que alocam o exemplar à família Baurusuchidae são: o quadrado altamente verticalizado, com a presença de uma concavidade na sua superfície lateral, a conformação da mandíbula, a presença de uma depressão longitudinal na porção anterior do jugal e a expansão descendente da aba lateral do esquamosal. A presente descrição de pós-crânio é a primeira realizada para um táxon da família extinta Baurusuchidae. Já foi noticiada a existência de material pós-craniano deste clado extinto de Crocodyliformes, porém nenhum exemplar foi realmente descrito até o presente momento. Esse material fóssil parece pertencer a novo táxon, devido à sua conformação peculiar do jugal, do processo retro-articular e da expansão descendente da aba lateral do esquamosal. Os caracteres levantados foram empregados para definir a posição filogenética e taxonômica do exemplar no grupo dos Notosuchia, e pretende-se, com isso, contribuir para a compreensão da diversidade dos mesmos. / The area of General Salgado (Adamantina Formation, Bauru Basin) is extremely rich in vertebrate fossils. This richeness is evident with the presence of several records of Cretaceous crocodiliforms. Among them, an articulated skeleton of a new Baurusuchidae was found, composed by parts of the cranium and a practically complete post-cranium. Characters that place the specimen in the family Baurusuchidae are: the highly verticalized quadrate, with the presence of a cavity in its lateral surface; the configuration of the jaw; the presence of a longitudinal depression in the first portion of the jugal; and the descendent expansion of the lateral edge of the esquamosal. The present postcranial description is the first one provided for taxon of the extinct family Baurusuchidae. This fossil material appears to belong to a new taxon, due to the peculiar configuration of its jugal, of the retro-articular process, and of the descendent expansion of the lateral edge of the esquamosal. The gathered caracters were used to define the filogenetic and taxonomic position of the specimen in Notosuchia. With this filogenetic analysis, it is expected to contribute with the comprehension of the diversity of the group.

The effectiveness of CO₂ injection in the subsurface for storage and EOR are controlled by reservoir quality variation. This study determines the depositional processes and diagenetic alterations affecting reservoir quality of the Lower Tuscaloosa Formation at Cranfield Field. It also determines the origin, time and processes of the grain-coating chlorite and its impacts on reservoir quality. Moreover, by integrating depositional and diagenetic characteristics and by linking them to sequence stratigraphy, the distribution of reservoir quality, could be predicted within a sequence stratigraphic framework. The studied sandstones are composed of medium to coarse-grained, moderately sorted litharenite to sublitharenite with composition of Q76.1F0.4L23.5. Depositional environment of this formation in the Mississippi Interior Salt Basin is interpreted as incised-valley fluvial fill systems. The cross sections and maps at the field show trend of the sandy intervals within channels with a NW-SE paleocurrent direction. During burial of the sandstones, different digenetic alterations including compaction, dissolution, replacement and cementation by chlorite, quartz, carbonate, kaolinite, titanium oxides, pyrite and iron-oxide modified the porosity and permeability. Among these, formation of chlorite coats plays the most important role in reservoir quality. The well-formed, thick and continuous chlorite coatings in the coarser grain sandstones inhibited formation of quartz overgrowth, resulted in high porosity and permeability after deep burial; whereas the finer grain sandstones with the poorly-formed, thin and discontinuous chlorite coatings have been cemented by quartz. The optimum amount of chlorite to prevent formation of quartz overgrowths is 6% of rock volume. The chlorite coats are composed of two layers including the inner chlorite layer formed by transformation of the Fe-rich clay precursors (odinite) through mixed-layer clays (serpentine-chlorite) during early eodiagenesis and the outer layer formed by direct precipitation from pore waters through dissolution of ferromagnesian rock fragments during late eodiagenesis to early mesodiagenesis. In the context of the reservoir quality prediction within sequence stratigraphic framework, the late LST and early TST are suitable for deposition of chlorite precursor clays, which by progressive burial during diagenesis could be transformed to chlorite, and thus results in preserving original porosity and permeability in deep burial. / text

A região de General Salgado (Formação Adamantina, Bacia Bauru) mostra-se como uma região extremamente rica em fósseis de vertebrados. Essa riqueza evidencia-se na presença de diversos registros de Crocodilianos do Cretáceo. Entre eles, encontra-se um esqueleto articulado, composto por partes do crânio e um pó-crânio praticamente completo. Os caracteres que alocam o exemplar à família Baurusuchidae são: o quadrado altamente verticalizado, com a presença de uma concavidade na sua superfície lateral, a conformação da mandíbula, a presença de uma depressão longitudinal na porção anterior do jugal e a expansão descendente da aba lateral do esquamosal. A presente descrição de pós-crânio é a primeira realizada para um táxon da família extinta Baurusuchidae. Já foi noticiada a existência de material pós-craniano deste clado extinto de Crocodyliformes, porém nenhum exemplar foi realmente descrito até o presente momento. Esse material fóssil parece pertencer a novo táxon, devido à sua conformação peculiar do jugal, do processo retro-articular e da expansão descendente da aba lateral do esquamosal. Os caracteres levantados foram empregados para definir a posição filogenética e taxonômica do exemplar no grupo dos Notosuchia, e pretende-se, com isso, contribuir para a compreensão da diversidade dos mesmos. / The area of General Salgado (Adamantina Formation, Bauru Basin) is extremely rich in vertebrate fossils. This richeness is evident with the presence of several records of Cretaceous crocodiliforms. Among them, an articulated skeleton of a new Baurusuchidae was found, composed by parts of the cranium and a practically complete post-cranium. Characters that place the specimen in the family Baurusuchidae are: the highly verticalized quadrate, with the presence of a cavity in its lateral surface; the configuration of the jaw; the presence of a longitudinal depression in the first portion of the jugal; and the descendent expansion of the lateral edge of the esquamosal. The present postcranial description is the first one provided for taxon of the extinct family Baurusuchidae. This fossil material appears to belong to a new taxon, due to the peculiar configuration of its jugal, of the retro-articular process, and of the descendent expansion of the lateral edge of the esquamosal. The gathered caracters were used to define the filogenetic and taxonomic position of the specimen in Notosuchia. With this filogenetic analysis, it is expected to contribute with the comprehension of the diversity of the group.