Hangenberg event
| Stratigraphy of the Hangenberg Event in the Rhenish Massif, Germany | |
| Date | Approximately 358.9 million years ago | 
|---|---|
| Location | Global, with notable deposits in Rhenish Massif, Poland, Morocco, and Ohio, United States | 
| Type | Mass extinction | 
| Cause | Likely anoxia, possible glaciation, euxinia, global cooling, and volcanism; supernova or asteroid impact are other hypotheses | 
| Outcome | Severe 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.