An international team of scientists have discovered traces of a new, previously unknown mass extinction, called the Carnian Pluvial Episode, which occurred 233 million years ago. It happened at the beginning of the Mesozoic era and contributed to the future prosperity of the dinosaurs. This is reported in an article published in the journal Science Advances.
Researchers analyzed the fossil data and found that the cause of the extinction was most likely the massive volcanic eruptions in western Canada, where huge volumes of volcanic basalt erupted. As a result of geological activity, a large amount of carbon dioxide was released into the atmosphere, causing global warming. Climate change has been accompanied by a period of high humidity lasting about one million years and a severe decline in ocean and land biodiversity.
The first dinosaurs appeared 20 million years before the Carnian perennial episode, but remained a rare group of reptiles. After a period of humidity, arid conditions set in, which gave rise to the flourishing of large lizards. At that time, not only dinosaurs appeared, but also many modern groups of plants and animals, including turtles, crocodiles, lizards and the first mammals. In the oceans, the carbon cycle has changed, allowing modern coral reefs and different types of plankton to exist.
Until now, scientists have known about five mass extinctions in the last 540 million years. The last mass extinction occurred about 65 million years ago and affected the dinosaurs.