End-Botomian mass extinction

Estimates for the decline in global diversity over these events range from 50% of marine genera[1] up to 80%.

[2] Among the organisms affected by this event were the small shelly fossils, archaeocyathids (an extinct group of sponges), trilobites, brachiopods, hyoliths, and mollusks.

[1][10] Evidence also exists for the development of anoxia (a loss of oxygen) in some environments in the oceans.

[1][11][12] One hypothesis that unifies this evidence links these environmental changes to widespread volcanic eruptions caused by the emplacement of the Kalkarindji Large Igneous Province or LIP.

[13][14][15] These widespread eruptions would have injected large amounts of greenhouse gases into the atmosphere causing warming of the climate and subsequent acidification and loss of oxygen in the oceans.