A relatively recently-discovered extinction caused by declining oxygen levels that saw the extinction of 99.5% of all microbial life. It may have paved the way for extreme anoxic conditions for the next billion years.
# Metadata
Title: Anoxic Catastrophe Movietime: 5:38 Geographical Time: 2050 Ma
After the initial rise in atmospheric oxygen, a major drop followed — possibly triggered by shifts in microbial ecosystems or changes in Earth's geochemistry. This decline led to a global crisis for early life forms adapted to oxygen-rich environments.
The resulting extinction event is believed to have wiped out nearly all microbial life, marking a dramatic reversal in Earth's biospheric development and ushering in a billion years of oxygen-deprived, sulfidic oceans known as the Canfield Ocean period.