Late Devonian extinction

The Late Devonian extinction was a series of widespread and complex die-offs of marine life around 375 million years ago. It occurred in multiple phases over several million years, dramatically reducing the diversity of fish, corals, and other marine organisms. Likely causes include drastic changes in ocean chemistry, global cooling, and possibly volcanic activity that led to lower oxygen levels or environmental stress. This event significantly reshaped marine ecosystems, paving the way for new groups of animals to evolve and dominate in the subsequent periods.