Speculated Causes of the Devonian Extinction
Evidence supporting the Devonian mass extinction suggests that warm water marine species were the most severely affected in this extinction event. This evidence has lead many paleontologists to attribute the Devonian extinction to an episode of global cooling, similar to the event which is thought to have cause the late Ordovician mass extinction. According to this theory,the extinction of the Devonian was triggered by another glaciation event on Gondwana, as evidenced by glacial deposits of this age in northern Brazil. Similarly to the late Ordovician crisis, agents such as global cooling and widespread lowering of sea-level may have triggered the late Devonian crisis.
Meteorite impacts at the Frasnian-Famennian boundary have also been suggested as possible agents for the Devonian mass extinction. Currently, the data surrounding a possible extra-terrestrial impact remains inconclusive, and the mechanisms which produced the Devonian
mass extinction are still under debate.
Permian Mass Extinction
Mass Extinctions of the Phanerozoic Menu