Major coral extinctions during the early Toarcian global warming event

Abstract The current loss of taxa from our planet is considered by many scientists to be the sixth mass extinction; in particular, coral reefs are experiencing significant damage. Scleractinian coral reefs constitute the framework of some of the most diverse ecosystems on Earth today as well as throughout the last 250 million years. The Pliensbachian-Toarcian (Pl-To) transition in the Early Jurassic is an important geologic analogue for present-day global disruptions as it provides insights about the ability of corals to survive significant changes in climatic and oceanic conditions. Based on a revised and greatly expanded taxonomy of Tethyan coral faunas for both stages, we reveal a catastrophic extinction (49% at genus and 90.9% at species level) and subsequent radiation for the group during the early Toarcian. The devastation during the late Pliensbachian and early Toarcian biotic crisis suggests that this interval is potentially the most important extinction event for scleractinian corals and fundamentally shaped the future of diversity and morphological disparity within the coral clades that flourished during the Jurassic and Cretaceous. Consequently, this interval should be considered a key period in the evolutionary dynamics of the group and reef ecosystems more broadly. These data on coral survival and recovery during the Early Jurassic event are particularly pertinent for questions about present day ecosystem collapse and conservation of coral habitats.