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The Carnian Pluvial Episode (Late Triassic) was a time of global environmental changes and possibly substantial coeval volcanism. The extent of the biological turnover in marine and terrestrial ecosystems is not well understood. Here, we present a meta-analysis of fossil data that suggests a substantial reduction in generic and species richness and the disappearance of 33% of marine genera. This crisis triggered major radiations. In the sea, the rise of the first scleractinian reefs and rock-forming calcareous nannofossils points to substantial changes in ocean chemistry. On land, there were major diversifications and originations of conifers, insects, dinosaurs, crocodiles, lizards, turtles, and mammals. Although there is uncertainty on the precise age of some of the recorded biological changes, these observations indicate that the Carnian Pluvial Episode was linked to a major extinction event and might have been the trigger of the spectacular radiation of many key groups that dominate modern ecosystems.

In the early Late Triassic a period of increased rainfall, named the Carnian Pluvial Event (CPE), is evidenced by major lithological changes in continental and marine successions worldwide. The environmental change seems to be closely associated with a negative carbon isotope excursion that was identified in a stratigraphic succession of the Dolomites (Italy) but the temporal relationship between these phenomena is still not well defined. Here we present organic-carbon isotope data from Carnian deep-water stratigraphic sections in Austria and Hungary, and carbonate petrography of samples from a marginal marine section in Italy. A negative 2-4‰ δ13C shift is recorded by bulk organic matter in the studied sections and is coincident with a similar feature highlighted in higher plant and marine algal biomarker carbon-isotope records from the Dolomites (Italy), thus testifying to a global change in the isotopic composition of the reservoirs of the exchangeable carbon. Our new observations verify that sedimentological changes related to the CPE coincide with the carbon cycle perturbation and therefore occurred synchronously within the western Tethys. Consistent with modern observations, our results show that the injection of 13C-depleted CO2 into the Carnian atmosphere-ocean system may have been directly responsible for the increase in rainfall by intensifying the Pangaean mega-monsoon activity. The consequent increased continental weathering and erosion led to the transfer of large amounts of siliciclastics into the basins that were rapidly filled up, while the increased nutrient flux triggered the local development of anoxia. The new carbonate petrography data show that these changes also coincided with the demise of platform microbial carbonate factories and their replacement with metazoan driven carbonate deposition. This had the effect of considerably decreasing carbonate deposition in shallow water environments. © 2014 Elsevier B.V

Amber is fossilised plant resin. It can be used to provide insights into the terrestrial conditions at the time the original resin was exuded. Amber research thus can inform many aspects of palaeontology, from the recovery and description of enclosed fossil organisms (biological inclusions) to attempts at reconstruction of past climates and environments. Here we focus on the resin itself, the conditions under which it may have been exuded, and its potential path to fossilisation, rather than on enclosed fossils. It is noteworthy that not all plants produce resin, and that not all resins can (nor do) become amber. Given the recent upsurge in the number of amber deposits described, it is time to re-examine ambers from a botanical perspective. Here we summarise the state of knowledge about resin production in modern ecosystems, and review the biological and ecological aspects of resin production in plants. We also present new observations on conifer-derived resin exudation, with a particular focus on araucarian conifer trees. We suggest that besides disease, insect attacks and traumatic wounding from fires and storms, other factors such as tree architecture and local soil conditions are significant in creating and preserving resin outpourings. We also examine the transformation of resin into amber (maturation), focusing on geological aspects of amber deposit formation and preservation. We present new evidence that expands previous understanding of amber deposit formation. Specific geological conditions such as anoxic burial are essential in the creation of amber from resin deposits. We show that in the past, the production of large amounts of resin could have been linked to global climate changes and environmental disruption. We then highlight where the gaps in our knowledge still remain and potential future research directions.

This is a repository copy of Multiple negative carbon-isotope excursions during the Carnian Pluvial Episode (Late Triassic).

The Permian-Triassic mass extinction is widely attributed to the global environmental changes caused by the eruption of the Siberian Traps. However, the precise temporal link between marine and terrestrial crises and volcanism is unclear. Here, we report anomalously high mercury (Hg) concentrations in terrestrial strata from southwestern China, synchronous with Hg anomalies in the marine Permian-Triassic type section. The terrestrial sediments also record increased abundance of fossil charcoal coincident with the onset of a negative carbon isotope excursion and the loss of tropical rainforest vegetation, both of which occurred immediately before the peak of Hg concentrations. The organic carbon isotope data show an ∼5‰–6‰ negative excursion in terrestrial organic matter (bulk organic, cuticles, and charcoal), reflecting change in atmospheric CO2 carbon-isotope composition coincident with enhanced wildfire indicated by increased charcoal. Hg spikes provide a correlative tool between terrestrial and marine records along with carbon isotope trends. These data demonstrate that ecological deterioration occurred in tropical peatlands prior to the main marine mass extinction.

The cause-and-effect relationship between the ca. 201 Ma eruption of the Central Atlantic magmatic province (CAMP) and the end-Triassic abrupt climate change and mass extinction is at present based on controversial temporal correlations. Upper Triassic sedimentary strata underlying CAMP basalts in Morocco illustrate a clear mineralogical and geochemical fingerprint of early CAMP basaltic eruptions, namely unusually high contents of MgO (10–32wt%) and of mafic clay minerals (11–84%). In the same rocks a coincident negative carbon-isotope excursion (CIE) is present, equivalent to the so-called ‘initial negative CIE’ recorded worldwide shortly before the Triassic–Jurassic boundary. The new data show that the onset of CAMP activity preceded the end-Triassic carbon cycle disruption and that the initial negative CIE is unequivocally synchronous with CAMP volcanism. The results of this study strongly support the hypothesis that the culmination of pollution of atmosphere and seawater by CAMP-derived volcanic gases was the proximate cause of the end-Triassic mass extinction