Oops, it's raining again

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Astronomical age constraints and extinction mechanisms of the Late Triassic Carnian crisis

2017

 

Miller, C.S., Petersen, F., Da Silva, A.C., Baranyi, V., Reichart, G.J, Kürschner, W.M.

Scientific Reports. 7, paper 2557

 

The dinosaurs disappeared at the end of the Cretaceous, 65 million years ago, probably after a collision between the earth and an asteroid. Their origin and climax is more mysterious and it could be linked to a period of climatic upheaval called "Carnian rain event" (or Carnian pluvial episode). The first dinosaurs appeared at the beginning of the Triassic, 245 million years ago, with arid climatic conditions and with a stable climate. They remained relatively insignificant for about 13 million years, until this Carnien event that allowed their expansion. At this time very humid conditions developped (humid tropical climate), interrupted by brief dry climatic phases. This allowed new plant species to develop, which would have allowed large herbivores to grow massively.

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These rainy events are associated with massive changes in the carbon cycle and Lottie Miller (University of Bremen) has shown that they are also associated with massive volcanic eruptions and methane, which could have strongly influenced the climate. We have worked to identify climatic cycles (see Milankovitch's cycles) and their precise duration are used as chronometers. This allows us for the first time to provide a very precise time scale for this succession of climatic events.

 

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