Hangenberg event

Hangenberg events
Stratigraphy of the Hangenberg Event in the Rhenish Massif, Germany
DateApproximately 358.9 million years ago
LocationGlobal, with notable deposits in Rhenish Massif, Poland, Morocco, and Ohio, United States
TypeMass extinction
CauseLikely anoxia, possible glaciation, euxinia, global cooling, and volcanism; supernova or asteroid impact are other hypotheses
OutcomeSevere decline in marine and terrestrial biodiversity; significant extinction of ammonoids, brachiopods, stromatoporoids, and several fish groups; near-total loss of reef ecosystems

The Hangenberg event, also known as the Hangenberg crisis or end-Devonian extinction, is a mass extinction that occurred at the end of the Famennian stage, the last stage in the Devonian Period (roughly 358.9 ± 0.4 million years ago). It is usually considered the second-largest extinction in the Devonian Period, having occurred approximately 13 million years after the Late Devonian mass extinction (Kellwasser event) at the Frasnian-Famennian boundary. The event is named after the Hangenberg Shale, which is part of a sequence that straddles the Devonian-Carboniferous boundary in the Rhenish Massif of Germany.