The End-Triassic Extinction (ETE) has long remained one of the lesser known among the so-called “Big Five”. There exist several hypotheses regarding the probable cause of this extinction, which can mainly be divided into  events of  a decline in the rate of diversification  in the late Triassic contra a sudden and significant extinction event. Primary amongst the sudden events is the one of outgassing and climate/environmental change induced by Central Atlantic Magmatic Province (CAMP) volcanism. This  study  aims to  describe  the ETE using  fluvial, lacustrine, deltaic  and  marginal-marine  microbial sedimentary  structures (MS), carbonatized microbial mats (CMM) as well as  wrinkle structures, microbially  induced  sedimentary  structures (MISS) from the latest  Triassic-  earliest  Jurassic  (TJB: Triassic-Jurassic boundary interval, Rhaetian to Hettangian) of Skåne, Southern Sweden. The MISS in these sites show a high diversity of structures, indicating microbial communities with high diversity in an environment usually dominated by bioturbating invertebrates. We observed structures that include top-surface (“Elephant skin”) and subsurface (“Kinneyia”) structures, carbon-rich fossilized microbial mats, microbial sideritic concretions, sideritized microbial mats, stromatolite-like layers and oncoids. Scanning Electron Microscopy (SEM) sampling also revealed structures related to the presence of both coccoidal and filamentous cyanobacteria.  Overall,  the diversity in observed structures indicate a thriving microbial community, with diversified and abundant ichnofossils or body fossils of possible bioturbators only observed in the early Rhaetian and younger Mid-Late Hettangian samples of deltaic or marginal-marine affinities. The lack of metazoan communities to such an extent indicates that the local environment could have reversed to a pre-Substrate Revolution state. The occurrence of abundant and  diversified  microbial structures in the studied  TJB  section,  representing  a relatively  short time interval, reflects anachronistic facies and development of abnormal biota. This supports the occurrence of several environmental distresses (abnormal hydrochemical and physical conditions) on the Triassic-Jurassic boundary interval, in turn lending credence to the hypothesis of an abrupt climactic event such as possibly that of CAMP volcanism. / <p>Presentation was carried out online over zoom due to the at the time ongoing COVID-19 pandemic.</p> / Resurrecting a lost world in Skåne: new light on the end-Triassic mass extinction and the origin of the dinosaur dominated ecosystem / Dinosaur grave from Skåne: microbiology, taphonomy and paleomolecules of exceptionally preserved theropod remains

Terrestrial carbon-isotope stratigraphy has proven a promising tool for stratigraphic correlation between the different exchangeable carbon-isotope reservoirs, as well as a powerful approach to reconstructing the evolution of δ13C of atmospheric CO2, which is closely associated with the evolution of palaeoenvironment and palaeoclimate. However, the limited understanding of pitfalls in specific application potentially restricts the method’s utility for stratigraphic correlation and palaeoenvironmental reconstruction. This thesis takes advantage of three case studies at two vital geological intervals which are both characterized by the significant carbon-isotope perturbation in the exchangeable reservoirs, to explore the nature of terrestrial carbon-isotope stratigraphy. Two of the case studies focus on the late Early to Middle Miocene, the period of the so called Monterey Event that is marked by remarkable positive carbon-isotope excursions in benthic and pelagic marine carbonate records. There are few terrestrial carbon-isotope records for the Monterey Event. In the present study, shallow marine sediments were collected from boreholes in the New Jersey margin, USA (IODP, Expedition 313) and North Sea Basin, Denmark. Phytoclasts are concentrated from palynological residues as the basis for a terrestrial carbon-isotope stratigraphy from the two locations. The carbon-isotope curves obtained can be correlated in detail locally, and correlated crudely on a global scale. However, there are no definite positive carbon-isotope excursions observed in the terrestrial isotopic stratigraphic records through the biostratigraphically determined Langhian interval equivalent to the Monterey Event. The reasons for the absence of relatively positive carbon-isotope excursions in terrestrial carbon-isotope stratigraphy might be caused by the reworking deposits of woody phytoclasts from older strata or some other process related to reworking. Another case study centres on the Triassic-Jurassic boundary and Early Jurassic fluvial and lacustrine succession in the Kuqa section, Tarim Basin, NW China. Macrofossil wood samples were collected to generate the terrestrial carbon-isotope stratigraphy. On the basis of the biostratigraphy and potential Stage/Age (sub-) boundaries implied by biological overturns, the terrestrial carbon-isotope stratigraphy in the Kuqa section can be well correlated with both terrestrial and marine carbon-isotope stratigraphic records from UK through the Early Jurassic. For the Triassic-Jurassic boundary, more precise correlation was made globally and an exact the position of Triassic-Jurassic boundary is proposed in the Kuqa section. In light of the biostratigraphy and the carbon-isotope stratigraphy obtained in the present study, an updated age assignment of the lithostratigraphic units is proposed to Age/Stage level in the Early Jurassic across the Northern Tarim Basin. The carbon-isotope stratigraphy thus significantly improves the terrestrial stratigraphic resolution. Terrestrial carbon-isotope stratigraphy is a powerful tool for global stratigraphic correlation and unifies stratigraphic correlation over marine and non-marine strata in cases when potential biasing factors are excluded.

This work is focused on characterising and evaluating the intensity and selectivity of the marine fauna during the Tr/J mass extinction and recovery of the ecosystem in different localities throughout Pangaea. To address this, four localities were studied: St. Audrie’s Bay, Larne and Pinhay Bay in the UK, and Portezuelo Providencia in Chile. From each locality, samples were taken at approximately 1m intervals throughout the Tr/J sections. Species abundance per sample was estimated and each species was classified according to autoecological information derived from the literature. In order to assess changes in the structure and composition of the assemblages, NMDS and beta diversity index were performed, dominance and richness were estimated and the data were tested against five rank abundance (RAD) models. Ecospace modelling was used to estimate the loss in ecological diversity. Measures of the body size of bivalves and ichno-parameters were recorded on each section. Through the UK sections, the richness, dominance and the composition rate shifted abruptly during the extinction event. A geometric model shows the best fit during extinction events and, in contrast, a log-normal model best fits the pre-extinction and recovery event. The body size of the bivalves did not decrease during the Tr/J, while the coverage, richness and body size of ichnofossils increased during the recovery. The Chile Tr/J section records low richness, but the ecological complexity and richness decreases through the interval and composition records high turnover, while the dominance increases. The results indicate that the Tr/J disruption changed species composition in a relatively short time period, which decreased the ecological functionality of the invertebrate marine assemblage. In spatial terms, the UK fauna show a clear response to the extinction effect, but the diversity response of the Chilean assemblage is not clear at all, which may be related to taphonomical bias. Alternatively, this work analysed stage-by-stage occupation of ecospace of 3181 genera recorded from Sepkoski`s compendium for the marine fauna from the Late Permian to Early Jurassic. The ecospace can be represented as a combination of the three axes of tiering, motility and feeding, each divided into six subcategories. From the Cambrian to Recent, ecospace utilisation has tripled, however the trend through the Phanerozoic remains unclear. This result indicates that from the Guadalupian to Sinemurian the number of modes of life did not increase significantly, but the ecospace packing does. There was a significant positive correlation between abundance of predators and both infaunalisation and motility. However, the ecospace utilisation decreased 35% and 16% at the end of Permian and Triassic, respectively. During the extinction events, non-motile animals, organisms with little physiological control of biocalcification and the epifaunal forms, were heavily affected. This indicates that the mass extinction had a particular ecological effect on the biota and is an important episode of ecological changes due to ecological selectivity. Parallel, the appearance of adaptations to new trophic niches during the Triassic, like durophagy, presumably increased predation pressure and drove the increase in benthic infaunalisation. This series of adaptation could be potentially associated with the Marine Mesozoic Revolution.

En tant qu'un des plus grands bassins sédimentaires du bloc de Chine du Sud, le bassin de Nanpanjiang a attiré une grande attention de la communauté géologique depuis de longtemps. Après plusieurs années de recherche, il reste encore de grand débats sur i) la provenance du bassin, ii) l'âge du changement de régime extension à compression, iii) le type de bassin et son contexte géodynamique. Dans cette thèse, nous avons conduit une étude pluri-disciplinaire incluant l'analyse des faciès sédimentaires et leur distribution géographique, paléocourants, spectres des minéraux lourds et leur geochimie, la géochronologie U-Pb sur zircon et baddeléyite, et le magnétisme des roches pour reconstrurier l'evolution de ce bassin. Les résultats indiquent un trois-étapes évolution. i) durant la période du Permien supérieur au début du Trias, la diabase mise en place 269Ma annonce l'ouverture du bassin, l'environnement sédimentaire est devenu plus profond. ii) durant la période du stade tardif du Trias inférieur (~ 245 Ma) au Trias moyen, à cause des influences de l'orogène Xuefengshan et de l'orogène d'Indochine situées à l'est et au sud du bassin, le bassin a évolué en bassin d'avant-pays. La diabase arrête sa mise en place durant cette période. Les analyses de détritus et de paléo-courants indiquent que durant cette période, les provenances de la partie est et de la partie sud du bassin étaient respectivement l'orogène Xuefengshan et l'orogène Indochinois. iii) la fin du Tirassique, la profondeur de l'environnement sédimentaire a fortement diminué, indiquant que le bassin a commencé à se rétrécir sous l'effet de la compression de l'orogène Xuefengshan et de l'orogène d'Indochine. / Ranks as the largest sedimentary basin in the South China during the Triassic, The Nanpanjiang basin attracts a large attention of the geology community for a long time. After many years study, there still exist several debates on i) the provenance of the sedimentary detritus, ii) the time of the change of the tectonic regime from extension to compression, iii) the type of the basin and its geodynamic background. In this thesis, a multidisciplinary study including analysis of sedimentary facies, paleo-current, frame work detritus mode, heavy mineral combinations and their geochemistry feature, rock magnetism and Zircon-baddeleyite isotopic dating on diabase was conducted to rebuild the evolution of the basin.The results show a three-stage evolution, i) during the Late Permian to the Early Triassic, the 269Ma diabase intruding into the basin announces the opening of the basin, the sedimentary environment became deeper. ii) During the late stage of the Early Triassic (~245 Ma) to the Middle Triassic, owing to the influences of the Xuefengshan orogen and the Indochina orogen which are located to the east and south of the basin, the basin evolved into a foreland basin. The diabase ceased emplacement in this period. The detritus and paleo-current analysis indicate that during this stage, the provenances of the East part and the South part of the basin were Xuefengshan Orogen and Indochina Orogen respectively. iii) During the Late Tirassic, the depth of the sedimentary environment decrease drasticly, indicating that the basin began to shrink owing to the compression of the Xuefengshan Orogen and the Indochina Orogen.

A influência da tectônica do supercontinente Gondwana é registrada no Gráben Arroio Moirão (RS), um relicto sedimentar associado ao Triássico da seção contínua da Bacia do Paraná, preservado sobre o Escudo Sul-Riograndense. Entretanto, o gráben dista 150 km da seção contínua e não apresenta nenhuma correlação estratigráfica clara. Baseado em novos dados sedimentológicos, paleontológicos e em abordagem de estratigrafia de sequências nova, se propõe um arcabouço estratigráfico para o Gráben Arroio Moirão e a sua correlação com a seção contínua da Bacia do Paraná. O gráben é composto pelo empilhamento de sequências de alta frequência, com granodecrescência ascendente, definido como flood units em um modelo de leques terminais. O conteúdo fossilífero corresponde à Sequência Candelária de idade Carniana, e estratigraficamente corresponde aos depósitos proximais da bacia triássica relacionados ao Escudo. As unidades do gráben estão em contato direto com o embasamento e está superfície representa um pulso de soerguimento, que erodiu as sequências anteriores, seguido por um rebaixamento que registrou a Sequência Candelária. A reativação das estruturas herdadas do embasamento é relacionada à orogenia triássica na margem sudoeste do Gondwana e responsável pelo controle deposicional dentro do Gráben Arroio Moirão. / The influence of Gondwana tectonics in the Triassic is registered in the Arroio Moirão Graben, a relict sedimentary unit associated with the Triassic section of Paraná Basin, preserved over the Sul-Riograndense Shield. However, this graben is 150 km far from the Paraná Basin and has no clear stratigraphic correlation with the main Triassic outcropping area. Based on new sedimentological, paleontological and sequence stratigraphy analysis, we propose a sequence stratigraphy framework for the graben units and correlation with the Triassic section of Paraná Basin. The graben has a stacking of high-frequency sequences with fining upward trend, defined as flood units in a Terminal Splay model. The fossil content corresponds to the Hyperodapedon assemblage zone with Carnian age. These sequences are correlated with Candelária Sequence from Paraná Basin and represent a more proximal facies-association related with a source-area from the shield. The graben units are directly overlying the basement units and this surface registers an uplift that eroded the previous sedimentary record of Paraná basin followed by a Middle Triassic basin wide subsidence. The reactivation of inherited structures from the basement was related to the southern Gondwana orogeny in Middle to Late Triassic that controlled the deposition in the Arroio Moirão Graben.

No presente trabalho é realizada urna revisão bibliograca dos estudos acerca dos rincossauros, com o objetivo de construir um histórico dos 164 anos de pesquisas sobre o gnipo. A classificação tradicional aceita para os rÍncossauros, divididos em duas famílias: Rhynchosauridae e Hyperodapedontidae, quando analisada aogeneticamente demonstra que Hyperodapedont idae se constitui em um clado rnonofiEtico, entretanto, Rhyncliosauridae apresenta-se como sendo um grupo pwafilktico . Discutimos os problemas taxonômicos relacionados a dois táxons coletados no Rio Grande do Sul, sendo eles: "Scaphonyx" sulcognathus , qual deverá ser designado um novo nome genérico e o "Rincossauro de Marimte" que será descrito formalmente no artigo em anexo como um novo gênero, passando a ser denominado Megaliorhynchusg ouldi.Para o Triássico do fio Grande do Sul os rincossauros estão presentes na Cenozona de Thempsida, que contém as Faunas Locais de Pinheiros e Chiniquá, com 0,7% de ocorrência, e Çenozona de Rhynchosada, que inclui a Fauna Local de Alemoa e parte da Fauna Local de Botucarai, com 92% de ocorrência. Em relação estado atual do conhecimento taxonômico acerca dos rincossauros, cosideramos como existentes atualmente 20 tkxom incluídos em Rhynchesauria, tendo sido estes reportados a partes Inferior, média e superior do Triássico. / A bibhographical revision of the studies about rhynchosaurs is made iri this assignment, with the purpose to build an hstorical of 164 years of researches about the group, specidy regarding to the taxonomical aspects. In relation to the current state of taxonomical knowledge about rhynchosam, we comider that 20 taxa are inclirde in Fthynchosauria, comuig fiom early, middle and late Triaçsic. Lhe tradicional classification accepted for the rhynchosaurs, divide them in two families: Rhynchosauridae and Hyperodapedontidae. Ho wever when it is fdogenetically analyzed, show us that Hyperodapedontidae is constitute in a monophyletic clade, but Rhynchosauridae is showed as a pmphyletic group. For the Triassic of Rio Grande do Sul, rhynchosaurs occur in Therapsida Cenozone, that contain the Local Faun of Pinheiros and Chiniq* with 0,7% of fiequency, and in the Rhynchosauria Cenozone, that include the Aiemoa Local-Fauna and pmt of the Botucarai Local-Fauna, with 92% o f frequency.Regarding to the rhynchosaurs from Rio Grande do Sul State, some taxonomical problems, related to two taxa, were discussed: "Scaphoqa 'ht~lcognathus, an hyperodapedontide of the Rhynchosauria Cenozorie, to whom a new generic name must be designated and the "Rincossauro de Mariante", a shynchosadde of the Therapsida Cenozone whose formal description constitute the subject of the attached artick. For this last it's proposed the creation of a new taxon nominated Megu~o~hyytehguos uldi.

No description available.

No presente trabalho é realizada urna revisão bibliograca dos estudos acerca dos rincossauros, com o objetivo de construir um histórico dos 164 anos de pesquisas sobre o gnipo. A classificação tradicional aceita para os rÍncossauros, divididos em duas famílias: Rhynchosauridae e Hyperodapedontidae, quando analisada aogeneticamente demonstra que Hyperodapedont idae se constitui em um clado rnonofiEtico, entretanto, Rhyncliosauridae apresenta-se como sendo um grupo pwafilktico . Discutimos os problemas taxonômicos relacionados a dois táxons coletados no Rio Grande do Sul, sendo eles: "Scaphonyx" sulcognathus , qual deverá ser designado um novo nome genérico e o "Rincossauro de Marimte" que será descrito formalmente no artigo em anexo como um novo gênero, passando a ser denominado Megaliorhynchusg ouldi.Para o Triássico do fio Grande do Sul os rincossauros estão presentes na Cenozona de Thempsida, que contém as Faunas Locais de Pinheiros e Chiniquá, com 0,7% de ocorrência, e Çenozona de Rhynchosada, que inclui a Fauna Local de Alemoa e parte da Fauna Local de Botucarai, com 92% de ocorrência. Em relação estado atual do conhecimento taxonômico acerca dos rincossauros, cosideramos como existentes atualmente 20 tkxom incluídos em Rhynchesauria, tendo sido estes reportados a partes Inferior, média e superior do Triássico. / A bibhographical revision of the studies about rhynchosaurs is made iri this assignment, with the purpose to build an hstorical of 164 years of researches about the group, specidy regarding to the taxonomical aspects. In relation to the current state of taxonomical knowledge about rhynchosam, we comider that 20 taxa are inclirde in Fthynchosauria, comuig fiom early, middle and late Triaçsic. Lhe tradicional classification accepted for the rhynchosaurs, divide them in two families: Rhynchosauridae and Hyperodapedontidae. Ho wever when it is fdogenetically analyzed, show us that Hyperodapedontidae is constitute in a monophyletic clade, but Rhynchosauridae is showed as a pmphyletic group. For the Triassic of Rio Grande do Sul, rhynchosaurs occur in Therapsida Cenozone, that contain the Local Faun of Pinheiros and Chiniq* with 0,7% of fiequency, and in the Rhynchosauria Cenozone, that include the Aiemoa Local-Fauna and pmt of the Botucarai Local-Fauna, with 92% o f frequency.Regarding to the rhynchosaurs from Rio Grande do Sul State, some taxonomical problems, related to two taxa, were discussed: "Scaphoqa 'ht~lcognathus, an hyperodapedontide of the Rhynchosauria Cenozorie, to whom a new generic name must be designated and the "Rincossauro de Mariante", a shynchosadde of the Therapsida Cenozone whose formal description constitute the subject of the attached artick. For this last it's proposed the creation of a new taxon nominated Megu~o~hyytehguos uldi.

The Late Rhaetian (Late Triassic) extinction event is characterised by shelled species showing a reduction in size, and thickness, which together with changed mineralogy is thought to be as a result of increased atmospheric pCO2 levels. Similar morphological changes have been demonstrated for extant species exposed experimentally to high CO2 leading to the hypothesis that Late Triassic extinctions were linked with global ocean acidification and increased oceanic palaeotemperatures. Consequently, the aim of this present work was to test this ocean acidification hypothesis by investigating morphological changes in selected shelled fossil species across this extinction event, and attempt to correlate them with changes in environmental temperature and pCO2. The abundance, size, shell thickness and mineralogy was determined for three common species, the bivalves Liostrea hisingeri and Plagiostoma gigantea and the ostracod Ogmoconchella aspinata collected from Triassic and Jurassic rocks from two locations in southwest England. Palaeotemperature was reconstructed from examination of these fossils and from the literature and atmospheric pCO2 estimated from published accounts. The shell size of bivalves increased during periods of high pCO2 and high palaeotemperature at both locations. Ostracod carapace sizes increased at St Audrie’s Bay but decreased at Lyme Regis during periods of high pCO2, while ostracod carapace size decreased during periods of high palaeotemperature at St Audrie’s Bay. However, ostracod shell thickness increased and decreased as pCO2 increased but shows no relationship with palaeotemperature at either location. Laboratory experiments on the effect of elevated pCO2 and elevated temperature on three modern species of ostracod was carried out. Modern species Leptocythere sp. and L. castanea subjected to either elevated pCO2 or elevated temperature showed increased dissolution, however size and thickness did not significantly change. In the same experimental conditions L. lacertosa showed increased dissolution however size continued to increase, while thickness was maintained. Comparison of fossil bivalve and ostracod data to modern high pCO2 and high temperature experiments illustrates some correlations to the modern experiments results indicating high pCO2 and high palaeotemperature conditions could have been occurring during the Triassic-Jurassic boundary interval. From the evidence presented, combined with an appropriate trigger (CAMP volcanism), it can be concluded that both ocean acidification and palaeotemperature were contributing to the species adaptations identified across the Triassic-Jurassic boundary interval.

A influência da tectônica do supercontinente Gondwana é registrada no Gráben Arroio Moirão (RS), um relicto sedimentar associado ao Triássico da seção contínua da Bacia do Paraná, preservado sobre o Escudo Sul-Riograndense. Entretanto, o gráben dista 150 km da seção contínua e não apresenta nenhuma correlação estratigráfica clara. Baseado em novos dados sedimentológicos, paleontológicos e em abordagem de estratigrafia de sequências nova, se propõe um arcabouço estratigráfico para o Gráben Arroio Moirão e a sua correlação com a seção contínua da Bacia do Paraná. O gráben é composto pelo empilhamento de sequências de alta frequência, com granodecrescência ascendente, definido como flood units em um modelo de leques terminais. O conteúdo fossilífero corresponde à Sequência Candelária de idade Carniana, e estratigraficamente corresponde aos depósitos proximais da bacia triássica relacionados ao Escudo. As unidades do gráben estão em contato direto com o embasamento e está superfície representa um pulso de soerguimento, que erodiu as sequências anteriores, seguido por um rebaixamento que registrou a Sequência Candelária. A reativação das estruturas herdadas do embasamento é relacionada à orogenia triássica na margem sudoeste do Gondwana e responsável pelo controle deposicional dentro do Gráben Arroio Moirão. / The influence of Gondwana tectonics in the Triassic is registered in the Arroio Moirão Graben, a relict sedimentary unit associated with the Triassic section of Paraná Basin, preserved over the Sul-Riograndense Shield. However, this graben is 150 km far from the Paraná Basin and has no clear stratigraphic correlation with the main Triassic outcropping area. Based on new sedimentological, paleontological and sequence stratigraphy analysis, we propose a sequence stratigraphy framework for the graben units and correlation with the Triassic section of Paraná Basin. The graben has a stacking of high-frequency sequences with fining upward trend, defined as flood units in a Terminal Splay model. The fossil content corresponds to the Hyperodapedon assemblage zone with Carnian age. These sequences are correlated with Candelária Sequence from Paraná Basin and represent a more proximal facies-association related with a source-area from the shield. The graben units are directly overlying the basement units and this surface registers an uplift that eroded the previous sedimentary record of Paraná basin followed by a Middle Triassic basin wide subsidence. The reactivation of inherited structures from the basement was related to the southern Gondwana orogeny in Middle to Late Triassic that controlled the deposition in the Arroio Moirão Graben.