No description available.

Questions as to the tempo and mode of changes in faunal composition at the Triassic/Jurassic boundary remain unanswered. Inquiries are hampered by a general paucity of sections containing correlatable Late Triassic/Early Jurassic strata. Vertebrate fossil material from Cromhall Quarry, recovered as part of an extended project centered on Late Triassic fissure infillings in southwestern Britain, was organized into a biostratigraphic scheme in 1993. This scheme could prove important in correlating Late Triassic continental strata. The Cromhall data consists of taxonomic counts from individual Stratigraphic levels within a series of fissures. Level counts were sorted into a series of sequential sedimentary and faunal associations that rest on the assumption that significant differences in faunal composition occur between individual fissures, but do not exist between individual sedimentary strata within any one fissure. Before the biostratigraphic framework could be utilized, the actual degree of similarity between the fissure faunas had to be quantified and tested. The original database, and counts from newly processed material, were subjected to Principle Components and Cluster Analyses. The analyses suggest that the majority of stratigraphic levels within any one fissure contain faunas with very similar composition. Levels from fissures that are temporally sequential contain faunas that are somewhat similar in composition. Overlap, in faunas found in strata at the top and bottom of sequential fissures, can be detected. In addition, there is a trend toward increased presence of certain taxa in the younger levels. These results indicate that the biostratigraphic framework may be used to enhance Triassic-Jurassic boundary research. / Master of Science

The central objective of this study is to understand phytoplankton community response following the global mass extinction event at the Cretaceous–Paleogene (K/Pg) boundary. The objective is approached through analysis of dinoflagellate cyst assemblages across the boundary interval in the North Pacific. Dinoflagellate cysts are powerful tools for deep time paleoenvironmental reconstructions and this group of microfossils has been vastly underutilized in this region of the world. On this premise, comprehensive marine palynological surveys were undertaken for the Oyster Bay Formation of eastern Vancouver Island, British Columbia, Canada and Shatsky Rise in the northwest Pacific. The Oyster Bay Formation work resulted in the discovery of the first K/Pg boundary succession west of the Rocky Mountains based on biostratigraphic controls and refined taxonomy for the genus Cannosphaeropsis found within these strata. Three new taxa are described: Cannosphaeropsis franciscana subsp. vacuoseptata subsp. nov., Cannosphaeropsis franciscana subsp. vesiculata subsp. nov. and Phelodinium fensomei sp. nov. The cyst assemblages reveal endemic associations and signals of transition between offshore coastal to estuarine settings in keeping with global eustatic trends. Oyster Bay Formation results and interpretations are compared to analyses of core samples from Deep Sea Drilling Project Site 577 at Shatsky Rise. Contrast is seen between a diverse, highly productive coastal to estuarine environment in the Oyster Bay Formation as represented by organic-walled taxa and an oligotrophic bathyal environment at Shatsky Rise during the same interval as represented by a small number of calcareous taxa. These two regions form the basis for comparison between differing assemblages in order to ascertain the extent to which phytoplankton communities were affected by changes in sea-surface and water mass conditions in conjunction with the K/Pg event. The findings reveal measurable impacts of climate and paleoenvironmental change reflected by shifts in assemblage composition and cyst morphology. A lack of extinction among many forms is consistent with studies from around the globe as presented in an exhaustive review of the literature. The dinoflagellates were marginally impacted with the most specialized taxa presenting a record of sea-surface temperature fluctuation, nutrient supply and opportunistic niche exploitation. / Graduate / 2022-08-20

In this thesis I document the biostratigraphy of two Cretaceous sections in Pakistan, the Chichali Nala Section and the Moghal Kot Section. Furthermore, I document the stratigraphy of the so-called Oceanic Anoxic Events (OAEs) in the Moghal Kot Section. In addition, I establish potential links between the planktonic foraminiferal evolution and these OAEs in the Moghal Kot Section. Sea Surface Temperatures (SSTs) are established for the Valanginian time by using the TEX86 and δ18O proxies in the Chichali Nala Section. The new biostratigraphy of the Chichali Nala Section shows that the ages of the sediments are mainly Valanginian. The biostratigraphy of the Moghal Kot Section show ranges in age from the Early Aptian to Early Maastrichtian. Seven OAEs were recorded in the Moghal Kot Section based on the combined study of biostratigraphy, microfacies, and δ13C analysis. These OAEs correlate well with previously documented OAEs elsewhere, therefore the new record of the OAEs in the Moghal Kot Section confirms the widespread occurrence of these events, possibly all global in nature. A quantitative review of the planktonic foraminiferal evolution in the Moghal Kot Section indicates that the environmental changes along the OAE2 have strongly forced the evolution of the planktonic foraminifera. Conversely, no clear relationship is observed between other OAEs and planktonic foraminiferal evolution in the same section. The SST results based on the TEX86 in the Chichali Nala Section show that the surface ocean was consistently much warmer (10-12 oC) than today at the paleolatitude of ~-35o during the Valanginian time. Such warm conditions are also supported by the spore and pollen assemblages of the Chichali Nala Section. Collectively the two datasets indicate strongly that the Valanginian world was overall extremely warm. Such warming during the Valanginian is incompatible with previously suggested cooler conditions during this time period.

Os depósitos triássicos continentais do sul do Brasil abrigam uma grande diversidade de tetrápodes terrestres, incluindo terápsidos, rincossauros, rincocefálios e arcossauros, como pseudosúquios e dinossauromorfos. Inserida neste contexto, a Formação Santa Maria, de porção superior datada do Carniano superior, tem papel fundamental no entendimento da origem e irradiação inicial dos dinossauromorfos, pois abriga alguns dos mais antigos registros do grupo em todo mundo, incluindo vários fósseis de dinossauros. Atualmente, a fauna de dinossauromorfos desta unidade é representada por Ixalerpeton polesinensis, Teyuwasu barberenai, Staurikosaurus pricei, Saturnalia tupiniquim, Pampadromaeus barberenai, Buriolestes schultzi e Bagualosaurus agudoensis, enquanto para o Noriano da Formação Caturrita são conhecidos Guaibasaurus candelariensis, Unaysaurus tolentinoi e Sacisaurus agudoensis. Visando o melhor entendimento da diversidade de dinossauromorfos oriundos destes depósitos, foram descritos, no contexto dessa tese, diversos novos fósseis do grupo: ULBRA-PVT059, 280, LPRP/USP 0651, MCN PV 10007-8, 10026, 10027 e 10049. Adicionalmente, foi considerado o recente histórico de pesquisas sobre a origens dos dinossauros para examinar o impacto de novas descobertas e das diferentes hipóteses filogenéticas no entendimento dos padrões biogeográficos da irradiação dos dinossauros. ULBRA-PVT059 e 280 representam os holótipos de duas espécies de dinossauromorfos: Ixalerpeton polesinensis e Buriolestes schultzi. I. polesinensis é o primeiro lagerpetídeo descrito para o Brasil e o único no mundo que preserva elementos do crânio e do membro escapular. O material revela que algumas características antes inferidas como sinapomórficas para Dinosauria já estavam presentes em outros dinossauromorfos. B. schultzi é um sauropodomorfo, provável grupo-irmão dos demais representantes do grupo. Além disso, sua anatomia dentária e relações filogenéticas sugerem que os primeiros dinossauros, incluindo os sauropodomorfos, eram adaptados a faunivoria. LPRP/USP 0651 é o holótipo de uma nova espécie de dinossauro, Nhandumirim waldsangae, da Formação Santa Maria. Apesar de incompleto, as partes preservadas mostram que este se tratava de um indivíduo juvenil, mas que difere em vários aspectos dos demais dinossauros do Carniano, em especial daqueles provenientes dos mesmos níveis estratigráficos. As relações filogenéticas de N. waldsangae indicam que o novo táxon se trata de um dinossauro saurísquio não-sauropodomorfo, possivelmente afim aos terópodos. MCN PV 10007-8, 10026, 10027 e 10049 se tratam de materiais de dinossauros provenientes da localidade tipo de Sacisaurus agudoensis. Estes representam um sauropodomorfo morfologicamente mais semelhante a membros mais recentes do grupo do que aqueles do Carniano. Assim, correlações bioestratigráficas sugeridas pela presença destes sauropodomorfos indicam uma idade mais nova para a localidade tipo de S. agudoensis do que a das biozonas carnianas. As análises biogeográficas consistentemente otimizaram a porção sul do Gondwana como a área ancestral de Dinosauria, o mesmo se dando para clados mais inclusivos. Estes resultados mostram que a hipótese em questão é robusta mesmo com maior amostragem taxonômica e geográfica, e independentemente das hipóteses filogenéticas. Desta forma, é demonstrado que não há suporte para a hipótese da Laurásia representar a área ancestral dos dinossauros. / The Triassic deposits of southern Brazil harbor a great diversity of terrestrial tetrapods, including therapsids, rhynchocephalians, rhynchosaurs, and archosaurs like pseudosuchians and dinosauromorphs. In this context, the Carnian Santa Maria Formation is important for the understanding of the origins and early diversifications of Dinosauromorpha, as it bears one of the oldest records for the group worldwide, including some of the oldest dinosaurs. Its dinosauromorph fauna is currently represented by Ixalerpeton polesinensis, Staurikosaurus pricei, Saturnalia tupiniquim, Pampadromaeus barberenai, Buriolestes schultzi, Bagualosaurus agudoensis, and Teyuwasu barberenai. In comparison, the Norian Caturrita Formation have yielded Guaibasaurus candelariensis, Unaysaurus tolentinoi, and Sacisaurus agudoensis. In order to better understand the dinosauromorph diversity from these deposits, several new fossil remains were described as parts of this thesis: ULBRA-PVT 059, 280, LPRP/USP 0651, MCN PV 10007-8, 10026, 10027, and 10049. In addition, the last 20 years of research efforts on the origins of dinosaurs were compiled to investigate the impact of new discoveries and conflicting phylogenetic hypotheses on the biogeographic history of early dinosauromorphs. ULBRA-PVT 059 and 280 represent the holotypes of a lagerpetid dinosauromorph, Ixalerpeton polesinensis, and a sauropodomorph dinosaur, Buriolestes schultzi. I. polesinensis is the first lagerpetid described from Brazil and only worldwide that preserves skull and scapular limb remains, showing that some previously inferred dinosaur synapomorphies were already present in other early diverging dinosauromorphs. B. schultzi is found as the sister-group to all other sauropodomorphs. In addition, its tooth anatomy and phylogenetic position suggest that early dinosaurs, including sauropodomorphs, were adapted to faunivory. LPRP/USP 0651 is the holotype of a new dinosaur, Nhandumirim waldsangae, from the Santa Maria Formation. Although incomplete, the preserved parts show that it was a juvenile individual, but differing in several respects from other Carnian dinosaurs, especially those from the same stratigraphic levels. The phylogenetic relations of N. waldsangae suggest that the new taxon is a nonsauropodomorph saurischian dinosaur, possibly related to theropods. Dinosaur materials from the type-locality of Sacisaurus agudoensis (MCN PV 10007-8, 10026, 10027, and 10049) represent a sauropodomorph, more similar morphologically to later members of the group than to those of Carnian age. Hence, biostratigraphic correlations suggested by these sauropodomorphs indicate an age for the type-site of S. agudoensis younger than that of the Carnian biozones. Biogeographic analyzes consistently optimize southern Gondwana as the ancestral area for Dinosauria, and this is also the case for more inclusive clades. The results show that the South Gondwanan hypothesis for the origin of dinosaurs is robust even with increased taxonomic and geographic sampling, and independent of phylogenetic uncertainties. It is, therefore, demonstrated that there is no support for Laurassia as the ancestral area of dinosaurs.

Localidades contendo tetrápodes fósseis do Permiano são conhecidas para a Formação Rio do Rasto (FRR) no sul do Brasil desde a década de 1970. Posteriormente, elas foram agrupadas em três “faunas locais”, correlacionáveis com as ocorrências de tetrápodes do Guadalupiano e do Lopingiano da África do Sul e da Rússia. Contudo, os fósseis de tetrápodes no Brasil ocorrem em afloramentos dispersos, isolados e discontínuos, de maneira que a maioria deles não possui dados precisos referentes ao seu posicionamento estratigráfico no sítio de coleta. Sugere-se que seja suspenso o uso do termo “fauna local” para as localidades contendo tetrápodes da FRR, pois elas provavelmente agrupam táxons que não são contemporâneos. A presente tese reconheceu dez localidades contendo tetrápodes nesta formação, mas apenas em quatro delas há o registro de terápsidos (Serra do Cadeado-EFCP, Fazenda Fagundes, Fazenda Boqueirão e Tiarajú-Barro Alto). Até o momento, terápsidos permianos são reportados na América do Sul apenas na FRR e compreendem anomodontes e dinocefálios. Aqui são relatadas duas novas ocorrências de terápsidos para esta unidade. O espécime UFRGS-PV-0487P foi identificado como um Tapinocephalidade indeterminado (Dinocephalia) e provém da localidade Serra do Cadeado-EFCP. Comparação com outros Tapinocephalidae indicam que UFRGS-PV-0487P é um espécime juvenil ou sub-adulto, semelhante a Moschops e Moschognathus da Zona de Assembleia (ZA) de Tapinocephalus da África do Sul. A segunda ocorrência de terápsido reportada aqui é baseada no espécime UNIPAMPA-PV-317P, reconhecido como um novo gênero e espécie de anomodonte (especificamente um dicinodonte). Características diagnósticas do novo táxon incluem cristas bem desenvolvidas (em norma ventral) a partir da placa mediana do pterigoide e ao longo dos ramos anteriores do pterigoide, ângulo marcado da porção posterior dos ramos do pterigoide, presença de pequenas presas caniniformes a partir de uma pequena incisura levemente posterior a cada processo caniniforme e presença de um processo retro-articular bem desenvolvido e em forma de bulbo na mandíbula. Não está claro ainda se o tamanho reduzido das presas caniniformes é devido à ontogenia, patologia ou a dimorfismo sexual. A análise filogenética indicou que UNIPAMPA-PV-317P é o membro mais basal de Bidentalia, um clado cosmopolita que inclui a maioria dos dicinodontes permianos e triássicos. Em relação às correlações bioestratigráficas possíveis para as localidades contendo tetrápodes na FRR, não é possível correlacionar estas localidades com apenas uma das ZAs da África do Sul ou mesmo da Plataforma Russa no momento, por que a FRR parece abrigar múltiplas assembleias de tetrápodes, das quais um retrato muito tendenciado é conhecido. Apenas a localidade de Aceguá Sítio 1 indica um pequeno refinamento, visto que os níveis abaixo da ocorrência de Provelosaurus americanus (um pareiassaurídeo) foram datados com métodos radiométricos e indicaram ser mais recentes do que 265 Ma, demonstrando que este sítio é correlacionável a partir da ZA de Tapinocephalus. / Permian tetrapod-bearing localities have been recovered from the Rio do Rasto Formation (RRF) in southern Brazil since the 1970s. Posteriorly, they have been grouped into three ‘local faunas’, correlated with the Guadalupian and Lopingian tetrapods of South Africa and Russia. However, tetrapod findings in the Brazilian deposit occur in disperse, isolated and discontinuous outcrops and most specimens lack precise data regarding their stratigraphic provenance. We suggest that the term ‘local fauna’ be discontinued for the tetrapod-bearing localities of the RRF, since they may be grouping non-contemporaneous taxa. The present study recognized ten tetrapod-bearing localities in this formation, but only four of them bear therapsid remains (Serra do Cadeado-EFCP, Fagundes Farm, Boqueirão Farm and Tiarajú-Barro Alto). Until date, Permian therapsids in South America are only known from the RRF and comprise anomodonts and dinocephalians. Here we report two new therapsid occurrences for this unit. The specimen UFRGS-PV-0487P was identified as a Tapinocephalidae indet. (Dinocephalia), from the Serra do Cadeado-EFCP locality. Comparison with other tapinocephalids indicates that UFRGS-PV-0487P is a juvenile or sub-adult specimen, which most closely resembles the ‘moschopines’ Moschops and Moschognathus from the Tapinocephalus Assemblage Zone (AZ) of South Africa. The second occurrence is based on the specimen UNIPAMPA-PV-317P, recognized as a new genus and species of anomodont (namely a dicynodont). Diagnostic features of the new taxon include well-developed ridges extending from the crista oesophagea anteriorly along the pterygoid rami, strong posterior angulation of the posterior pterygoid rami, small tusks erupting from a short incisure slightly posterior to each caniniform process and well-developed bulbous retroarticular process of the articular. It is not clear whether the reduced size of the tusks represents pathology, an ontogenetic feature or sexual dimorphism. Phylogenetic analysis indicates that UNIPAMPA-PV-317P is the most basal member of Bidentalia, a cosmopolitan clade that includes most of the Permian and Triassic dicynodonts. It is not possible at the moment to constrain the time interval of the tetrapod-bearing localities of the RRF to only one biozone of South Africa or Russia because the RRF seems to bear incomplete but multiple faunal assemblages. Aceguá Site 1 age is better constrained due to radiometric dating, but it only indicates that the levels bearing the pareiasaurid Provelosaurus americanus are younger than 265 My and can be correlated with the Tapinocephalus AZ.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / O presente estudo baseou-se na análise das variações verticais do conteúdo orgânico de 50 amostras derivadas do furo de sondagem 9-FBA-61-BA, que permitiu conhecer melhor os representantes palinofaciológicos e palinológicos do Cretáceo Inferior da Bacia do Recôncavo, na área estudada. Através da observação a luz da microscopia óptica em luz branca transmitida e luz ultravioleta, foi possível posicionar temporalmente a seção, e individualizar quatro tipos de palinofácies distintas, levando-se em conta os tipos e o grau de preservação da matéria orgânica. As análises quantitativas do conteúdo orgânico mostram um predomínio de material orgânico de origem alóctone, representado por grãos de pólen, esporos e fitoclastos na base e no topo da seção, sendo sua porção média dominada por material orgânico amorfo autóctone. As mais altas fluorescências são observadas nas porções média e basal da seção indicando um ambiente mais redutor à época de sedimentação, destes estratos. Os dados de ICE apresentam valores de maturação entre 4,5 e 5,0 caracterizando um material orgânico maturo para geração de hidrocarbonetos. A associação palinoflorística identificada, bem como os dados litológicos obtidos, indicam um paleoambiente exclusivamente continental, composto por um sistema fluvial e deltaico-lacustre, sob um clima quente árido para a época deposicional. Tal associação enquadra-se àquelas observadas nas bacias do nordeste brasileiro e insere-se nas características das associações pertencentes à Província Microflorística Dicheiropollis (ex-WASA). Foram identificadas 57 espécies de palinomorfos, incluindo grãos de pólen, esporos, algas e fungos. A detecção das espécies, Dicheiropollis etruscus e Aequitriradites spinulosus, nos permitiu posicionar o intervalo nas biozonas Vitreisporites pallidus e Dicheiropollis etruscus, consideradas como de idades Hauteriviano Barremiano. / The present study was based on vertical variations analysis of the organic matter from 50 core samples collected from the well 9-FBA-61-BA, allowing better understanding of the Early Cretaceous of Reconcavo Basin palynological and palynofacies characteristics. Observations throughout combined light and blue light/UV fluorescence techniques, permitted to defined the section depositional time, and to distinguish four individual types of palynofacies, taking into account the variety and degree of preservation of organic matter.. Quantitative analysis of the organic content shows a predominance of allochthonous organic matter, represented by pollen, spores and phytoclasts on the base and top of the section; however the middle part is dominated by amorphous organic matter. On the other hand, the highest fluorescence was observed at the base and middle portion of the section suggesting a low oxidizing level at this sedimentation time. ICE data presents mature values ranging between 4.5 to 5.0 indicating that the deposits are in the oil generation window. The identified palynoflora and obtained lithological data suggests an exclusively continental paleoenvironment, composed by fluvial and deltaic - lake systems, in a warm and arid climate at the deposition time. Were identified 57 species of palynomorphs, including pollen, spores, algae and fungi. The detection of the Dicheiropollis etruscus and Aequitriradites spinulosus index species indicates these deposits belong to the Hauterivian - Barremian Vitreisporites pallidus and Dicheiropollis etruscus palynozones, respectively. This assemblage fits into those observed in the Brazilian northeastern basins and have the microfloristic assemblage characteristics that fit in to the Dicheiropollis Province (= WASA Province).

O presente estudo integra informações bioestratigráficas e paleoecológicas obtidas através da análise de foraminíferos planctônicos e bentônicos recuperados dos sedimentos provenientes de cinco poços (1-MAS-1, 1-MAS-3A, 1-MAS-4A, 1-MAS-14 e 1-MAS-15) da Bacia de Barreirinhas, perfazendo um total de 127 amostras de calha preparadas e analisadas. Os sedimentos aqui analisados abrangem os andares Albiano superior ao Campaniano superior com registro geológico inserido nos grupos Caju (Albiano - Cenomaniano) e Humberto de Campos (Turoniano - Maastrichtiano). Através dos dados bioestratigráficos obtidos foi possível estabelecer sete biozonas de foraminíferos, de caráter local, com base na última ocorrência do táxon guia (LAD - Last Appereance Datum). O Albiano superior foi definido com base nas biozonas do foraminífero planctônico Ticinella primula Lauterbacher (1963) e foraminíferos bentônicos Lingulogavelinella albiensis Malapris (1965)-Gyroidina bandyi Trujillo (1960); o Cenomaniano inferior foi determinado através das biozonas do foraminífero planctônico Globigerinelloides bentonensis Morrow (1934) e foraminífero bentônico Coronorotalites aptiensis Bettenstaedt (1952); o Cenomaniano superior foi reconhecido através das biozonas do foraminífero planctônico Rotalipora appeninica Renz (1936) e foraminífero bentônico Gavelinella intermedia Berthelin (1880); o Campaniano superior foi determinado com base na biozona do foraminífero planctônico Heterohelix pulchra Brotzen (1936). Após a identificação da microfauna, foi possível reconhecer 108 espécies de foraminíferos pertencentes a cinco subordens: a Subordem Globigerinina, de foraminíferos planctônicos, é representada por 40 espécies e 15 gêneros; os foraminíferos bentônicos são compostos por 68 espécies e 48 gêneros, pertencentes as Subordens Rotaliina, Textulariina, Lagenina e Miliolina. Através da análise da assembléia de foraminíferos, foi possível traçar a CCD (Carbonate Compensation Depth - Profundidade de Compensação do Carbonato) nos poços e separá-los com base na profundidade em: distais (1-MAS-1 e 1-MAS-14) e proximais (1-MAS-3A, 1-MAS-4A e 1-MAS-15). Observou-se que a Bacia de Barreirinhas possui uma tendência geral transgressiva ao longo do Período Cretáceo, caracterizada por meio do influxo sedimentar através de variações climáticas, como o aquecimento global ocorrido neste período. Esta teoria é reforçada pela completa ausência de tecas calcárias, tanto de foraminíferos bentônicos, quanto planctônicos, associada à ocorrência exclusiva de bentônicos aglutinantes e silicosos (Reophax globosus) nos poços distais ao final do Período Cretáceo. Nos poços 1-MAS-3A, 1-MAS-4A e 1-MAS-15, a fauna de foraminíferos identificada apresenta adaptações morfológicas a condições de baixa oxigenação na coluna d'água, características normalmente observadas durante os Eventos Oceânicos Anóxicos (Oceanic Anoxic Event - OEA). Como exemplo destas adaptações morfológicas, foram identificadas três espécies pertencentes ao gênero Schakoina, que possui câmaras alongadas e a espécie Biticinella breggiensis, que possui câmaras bilobadas, sugerindo um aumento na produtividade primária, disponibilidade de nutrientes e paleoambientes depletados em oxigênio. Com base nestas informações foi possível identificar que um Evento Anóxico de caráter local tenha ocorrido durante o Albiano superior, registrado somente nos poços 1-MAS-3A e 1-MAS-4A, enquanto que o Evento Anóxico Global 2 foi registrado no poço 1-MAS-15. / This study integrates biostratigraphic and paleoecological information obtained through of planktonic and benthic foraminifera analysis from sediment recovered from five wells (1-MAS-1, 1-MAS-3A, 1-MAS-4A, 1-MAS-14 and 1-MAS-15) of Barreirinhas Basin, making a total of 127 samples prepared and analyzed. The sediments analyzed here cover the upper Albian to upper Campanian stages with geological record inserted in the Caju (Albian - Cenomanian) and Humberto de Campos (Turonian - Maastrichtian) groups. Through the biostratigraphic data obtained it was possible to establish seven foraminiferal biozones, of local character, based on the last occurrence of taxon guide (LAD - Last Appereance Datum). The upper Albian was defined based on planktonic foraminifera biozones of Ticinella primula Lauterbacher (1963) and benthic foraminifera Lingulogavelinella albiensis Malapris (1965)-Gyroidina Bandy Trujillo (1960); the lower Cenomanian was determined through the planktonic foraminifera biozones of Globigerinelloides bentonensis Morrow (1934) and benthic foraminifera Coronorotalites aptiensis Bettenstaedt (1952); the upper Cenomanian was recognized through the planktonic foraminifera biozones of Rotalipora appeninica Renz (1936) and benthic foraminifera Gavelinella intermedia Berthelin (1880); the upper Campanian was determined based on the planktonic foraminifera biozone Heterohelix pulchra Brotzen (1936). After the identification of microfauna, was possible to recognize 108 species of foraminifera belonging to five suborders: the Suborder Globigerinina, of planktonic foraminifera, is represented by 40 species and 15 genera; the benthic foraminifera are composed of 68 species and 48 genera, belonging to the suborders Rotaliina, Textulariina, Lagenina and Miliolina. Through analysis of foraminifera assemblage it was possible to trace the CCD (Carbonate Compensation Depth) in the wells and separate them based on depth in: distal (1-MAS-1 and 1-MAS-14) and proximal (1-MAS-3A, 1-MAS-4A and 1-MAS-15). It was noted that the Barreirinhas Basin has an overall transgression during the Cretaceous Period, characterized by sedimentary influx through weather changes, like global warming that occurred during this period. This theory is enhanced by the complete absence of calcareous tests, both of benthic as planktonic foraminifera associated with the exclusive occurrence of agglutinating and arenaceous benthic (Reophax globosus) in the distal wells of the end of Cretaceous Period. In the wells 1-MAS-3A, 1-MAS-4A and 1-MAS-15, the foraminifera fauna identified presents morphological adaptations to conditions of low oxygen in the water column, features typically seen during the Oceanic Anoxic Event (OEA's). As examples of these morphological adaptations, was identified three species of the Schakoina genera, which has elongated chambers and Biticinella breggiensis species, which has bilobeted chambers, suggesting an increase in the primary productivity, nutrient availability and paleoenvironments depleted in oxygen. Based on this information it was possible to identify a local character anoxic events occurred during the upper Albian, recorded only in a well 1-MAS-3A and 1-MAS-4A, while the global anoxic event 2 was recorded in a well 1-MAS-15.

The Lower to Middle Ordovician Garden City Formation and Pogonip Group are coeval successions of mixed carbonate and siliciclastic rocks deposited under normal marine conditions on a shallow carbonate ramp on the western margin of Laurentia. The Garden City Formation was deposited in the Northern Utah Basin and the Pogonip Group was deposited in the Ibex Basin. These two basins experienced different rates of thermal subsidence following Neoproterozoic rifting along the western margin of Laurentia resulting in significant thickness differences between rock units and varying lithologic expressions of eustatic change. This study provides a unique opportunity to examine the lithologic, geochemical, and paleontological responses to eustatic oscillations of two coeval sedimentary basins in Utah that formed under different tectonic settings and subsidence rates. The Garden City Formation is composed of fourteen lithotypes and the Pogonip Group is composed of eleven lithotypes. These lithotypes mainly represent depositional environments ranging from inner ramp and middle ramp with minor outer ramp deposits. Many lithologies appear to be storm influenced due to the presence of abundant rip-up clasts (intraclasts), fragmented bioclasts, and occasional mega-ripples. Other lithologies have been extensively bioturbated and burrowed. Nine stratigraphic sequences have previously been identified within the Pogonip Group. Eight equivalent, albeit compressed, sequences within the Garden City Formation were located using biostratigraphic and chemostratigraphic correlations, and increases in insoluble residues often found at the bases of sequence boundaries. Sequences are expressed as deepening-upward packages containing silty/sandy lowstand deposits that transition into wackestones and lime mudstone-rich highstand deposits. Several sequence boundaries appear to coincide with conodont and/or trilobite extinction events. Important sequence boundaries mark the Sauk III-m and Sauk IV-m transition and the Ibexian- Whiterockian Series boundary. Meter-scale cycles are common and likely related to Milankovitch cyclicity. Insoluble residue increases upsection at each location which may indicate a gradual overall drop in sea level due to the onset of the regressive upper portion of the Sauk III supersequence. Insoluble residue from the Pogonip Group ranges from 1.2 to 84.7 wt. % with an average of 16.0 wt. % ± 0.7 wt. %. Insoluble residue from the Garden City Formation ranges from 1.5 to 63.8 wt. % with an average of 13.4 wt. % ± 1.0 wt. %. New stable carbon isotope data (δ13C) from the Garden City Formation and the Pogonip Group range from -2.92 to 1.23 ‰ V-PDB and -2.19 to 0.56 ‰ V-PDB, respectively. Four distinct δ13C trends are recognized in both sections: 1) a drop in δ13C from positive values between 0.2-1.0 ‰ to negative values approaching -1.0 ‰ near the base of the Ordovician, 2) a 0.5 to 1.0 ‰ positive δ13C excursion near the top of the Rossodus manitouensis Zone, 3) a drop in δ13C values to near -2.0 ‰ through most of the Acodus deltatus –Oneotodus costatus Zone, and 4) a gradual increase in δ13C from - 2.0 ‰ to -1.0 ‰ throughout the remainder of the sections. δ13C of the Garden City Formation and the Pogonip Group appear to be correlative based on these distinct trends. This correlative relationship was verified by the lowest occurrence of conodont species Scolopodus filosus and Scalpellodus n. sp. A of the Low Diversity Interval which coincides with the positive δ13C excursion in both the Garden City Formation and the Pogonip Group. New δ13C data likely represent global primary seawater chemistry based on the correlation of similar δ13C trends from the Argentine Precordillera and western Newfoundland.

Devonian miospore assemblages from 16 sections in Saudi Arabia and North Africa are studied in order to characterize the palynostratigraphy of the northern margin of western Gondwana which remains poorly known in Saudi Arabia. The preliminary taxonomic work identifies more than 200 miospore species, including a lot of new species endemic to western Gondwana. Numerous species have still to be more precisely circumscribed because of their large morphological variability. Others show continuous intergrading morphological variation. The morphological variability of each taxon is one of the main problems in any palynological study. It is due to phylogenetic evolution, ontogeny (maturation of sporangia) and taphonomic factors. Although the standard Devonian miospore zonations established in Euramerica (Richardson & McGregor, 1986; Streel et al., 1987) are commonly used in most of the palynological studies, they are not always easily recognizable in western Gondwanan localities because of the endemic nature of the assemblages. Therefore, a new local/regional biozonation based on the characteristics of the miospore assemblages described here was needed for a more accurate correlation. The new established biozonation consists of 9 assemblage zones, 8 interval zones and 2 acme zones, extending from the late Pragian to the late Givetian and possibly the early Frasnian. The new defined biozones are compared to other coeval biozones defined in the literature. Thanks to this new local/regional biozonation, reliable correlations are established between sections. Numerous oilfields occur in the Devonian from western Gondwana. A biozonation based on the first down-hole occurrence of species is developed for oil exploration. Thanks to this type of biozonation, only the top of a biozone has to be reached in order to be identified. The use of this biozonation is facilitated by the choice of easily recognizable and common index species. This provisional downward biozonation consists of 8 interval zones. Although it seems relatively reliable by comparison with the previously defined upward biozonation, it needs to be further tested on other drilled sections. The review of the Emsian-Givetian miospore assemblages from the literature allows to evaluate the provincialism of assemblages on a worldwide scale during this interval. Coefficient of similarity is calculated between palynofloras from northern Euramerica, southern Euramerica, eastern Gondwana, southwestern Gondwana and northwestern Gondwana. The resulting low values correspond to low to moderate similarity of miospore assemblages between the considered regions in the Emsian-Givetian interval. The provincialism may be explained by a latitudinal climatic gradient as no palaeogeographic barrier is known during this time interval. Indeed, both Euramerican and Gondwanan land masses were very close as soon as the earliest Devonian. Despite a certain degree of provincialism, floristic interchanges existed. Northwestern Gondwana constituted an intermediate warm temperate region with shared taxa mainly from more arid Euramerican localities in the North, and cooler southwestern Gondwanan localities in higher latitudes. However, it seems that a progressive homogenization of the vegetation took place in Middle Devonian as the standard Euramerican biozones are more easily recognized in Givetian than in Eifelian and Emsian. This transition from provincialism to cosmopolitanism during the Devonian is not only shown by palynofloras but also by the palaeogeographic distribution of many other fossil groups. It is likely due to a decrease of the latitudinal climatic gradient in Middle Devonian.