Early Triassic - Smithian-Spathian Extinction

Smithian-Spathian Extinction

Until recently the existence of an extinction event about 3 million years following the end-Permian extinctions was not recognised, possibly because there were few species left to go extinct. However, studies on conodonts have revealed that temperatures rose in the first 3 million years of the Triassic, ultimately reaching sea surface temperatures of 40°C in the tropics around 249 million years ago. Large and mobile species disappeared from the tropics, and amongst the immobile species such as molluscs only the ones that could cope with the heat survived, whilst on land the tropics were practically devoid of life.

Big, active animals only returned to the tropics, and plants recolonised on land when temperatures returned back to normal around 247 million years ago.