The Carnian Pluvial Episode, a major climate change event that occurred around 234 to 232 million years ago (Late Triassic epoch), was a time of global environmental changes and possibly substantial volcanism.

A new analysis of paleontological data suggests that this event was a major — but previously neglected — time of extinction and may be linked to the disappearance of up to 33% of all marine genera (invertebrates, vertebrates, and protists) as well as many tetrapod clades and to the explosive diversification of many key modern groups of plants and animals (conifers, insects, dinosaurs, crocodiles, lizards, turtles, and mammals).

Summary of major extinction events through time, highlighting the Carnian Pluvial Episode at 233 million years ago.

The warming was associated with increased rainfall, and this had been detected back in the 1980s by geologists Mike Simms and Alastair Ruffell as a humid episode lasting about one million years in all.

The climate change caused major biodiversity loss in the ocean and on land, but just after the extinction event new groups took over, forming more modern-like ecosystems.

“We now know that dinosaurs originated some 20 million years before this event, but they remained quite rare and unimportant until the Carnian Pluvial Episode hit.”.