A new study challenges the long-standing belief that the Late Ordovician mass extinction event (LOME), which occurred 443 million years ago and wiped out approximately 85% of species, was primarily due to a short ice age. Researchers from the universities of Copenhagen, Ghent, and California-Berkeley suggest that global warming played a significant role, with mass extinctions occurring over several million years during a warming phase before the known glacial extinction pulses. The study indicates that the biodiversity loss was more complex, occurring in at least three pulses over up to nine million years, reshaping our understanding of the event’s drivers.
Disagreements within the scientific community regarding the mechanisms of LOME persist, but a revised hypothesis links the extinction event to large volcanic eruptions that contributed to greenhouse gas emissions and ocean deoxygenation. The study’s findings draw parallels to today’s biodiversity crisis driven by anthropogenic activities, suggesting that the current extinction rates, while not yet at the historical mass extinction scale, are alarming. Improved fossil data reveals that sudden extinction pulses punctuate prolonged biodiversity declines, raising concerns about potential irreversible ecosystem disruptions similar to past events in Earth’s history.
