Permo-Triassic mass extinction
- Created by: Brad_ers_B
- Created on: 19-04-15 15:46
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- Permo-Triassic mass extinction
- What we know
- Around 251 million years ago
- Marks the end of the Palaeozoic Era
- Around 95% of all marine invertebrates extinct
- Extinct - Trilobites, tabulate corals, rugos corals and many brachiopods
- Depleted - Foraminifera and cephaalopods
- 77% of tetrapods, large amphibians and insects extinct on land
- Super-continent formation
- End of Permian = Pangaea formed
- Fewer continental shelves
- Lack of shallow marine habitat
- Evidence in decline of shallow marine species
- Presence of single continent caused rapid climate fluctuations
- Unstable weather
- Single continent= reduced input into oceans from rivers / estuaries
- Less amount of nutrients available for shallow marine life
- Possibly altered salinity of oceans
- Widespread glaciation in southern hemisphere (Australia, South Africa, South America, Antarctica)
- Sea level fall (regression)
- Reduced shallow shelf environments
- Major volcanic activity (Siberian Traps)
- Believed to be the largest volcanic eruption in Earth History
- Emission of poisonous gasses
- Kill any plants or animals close by
- Gas+Ash emitted during eruption
- Could've initially lowered global temps by blocking heat from the sun
- As it was global it could have caused global glaciation and sea level falls
- May have lasted from hundreds to thousands of years
- Emission of Greenhouse Gasses like CO2 and SO2
- Increase in Global temperatures after cooling period
- Could have lasted for thousands to millions of years
- Methane hydrates (methane ice)
- Solid form of methane believed to have formed within sediments
- Solid and stable up to around 18°C
- The global temperature increase could have triggered the release of these hydrates
- Mobile and gaseous on the seabed
- Could have disrupted life in the seas + increased greenhouse gasses
- Solid form of methane believed to have formed within sediments
- What we know
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