Permian-Triassic Extinction “The Mother of all Extinctions”

1. Permian-Triassic Extinction“The Mother of all Extinctions” Anne Kleinhenz

2. Permian-Triassic Extinction • What was it? • The mass extinction at the end of the Permian that wiped out almost all life • Took place about 250mya • Paleozoic and Mesozoic Eras • Took place over a span of 5-10 million years

3. When? • 5-10 million years is an abnormally long time • Many taxa slowly died out in the beginning • Towards the end, extinctions were more rapid

4. When? • Boundary sections in South China show that 280 out of 329 marine invertebrate genera disappear within the final 2 conodont zones of the Permian • In boundary sections preserving a record of the P-Tr transition, large numbers of species disappear over few meters of sediment or less.

5. How Big? • Systematic collections show that ~50% of families, and perhaps as much as 90% of all species known from the late Permian disappear from the fossil record during the latest Permian • Killed about 95% species in oceans • Marine invertebrates were hit the worst by extinction

6. What Died? • All trilobites • 94% Graptolites • All Blastoids, Acanthodians, Rugose and Tabulate Corals, Pelycosaurs • 98% Crinozoans • 96% Anthozoans • 96% Brachiopod genera

7. What Else Died? • 85% Gastropods • 59% Bivalves • 79% Bryozoans • 90% Gastropod genera and • 3 of 16 Gastropod families • 97% Ammonoids

8. Vertebrates That Died • Extinction for the vertebrates was far less severe than for the invertebrates • This has led to less research and literature on these organisms being published • Tetrapods, amphibians, reptiles were all very prominent during this age

9. Vertebrates That Died and Lived • Amphibians died out as the pools of water in which they lived in dried up • Amniota then became dominant • By Mid-Permian the Therapsids became dominant • Archosauriformes were also evolving at the time, and were one of the few vertebrates to make it through the extinction and diversify

10. Vascular plants • Vascular plants showed no major drop or change in numbers • The fossil record shows a gradual transition from Paleozoic to Mesozoic floras • Took place over a period of about 25 million years

11. Why? • There are many theories of what caused one of the larges extinctions in history: • Volcanism • Impact • Climate Change • Formation of Pangaea • Glaciation • Others

12. Impact • There is some evidence supporting this theory • Nickel-rich Layers • From impact or heavy-metal rich mantle-derived lavas • Shocked quarts • Bedout Crater in Australia

13. Pangaea • Formed during the Late Permian • Tectonic movement of the plates had many side effects • Most was inland, so weather was hot and dry in low lying areas, and unseasonable weather patterns in higher altitudes • Movement of species and more competition • Extreme flooding due to glacial melting and caused reduced land area

14. Volcanism • The Siberian Traps • Volcanoes cover approximately 2,000,000 km2 in Siberia (greater area than Europe) • Eruptions lasted at full intensity for about a million years

15. Volcanism • The Siberian Traps has climate altering potential by the emission of ash and gases. • Initially sulfur aerosols and volcanic ash block out sunlight, causing rapid cooling. • Ash and sulfur aerosols can remain in the upper atmosphere for 100's to 1000's of years which would be enough to cause a significant glaciation. • At the end of the Permian period the biggest ever drop in sea level in history occurred, indicating large scale glaciation.

16. Volcanism • Greenhouse gases warm the climate by allowing sunlight to pass through • Heat reflected by the Earth itself cannot penetrate the atmosphere so is retained. • Greenhouse gases stay in the atmosphere much longer so their climate changing effects can last for millions of years.

17. Another Volcanic Theory • PBS Nova Special

18. Linked Theories • “The Pangean super continent led to many changes in the shape of the land, glaciation patterns and climate, which in turn altered sea level and salinity of the oceans. These affects are often interlinked. The presence of Pangaea helped to initiate extreme environments, and along with other evidence, such as volcanism and impact, led to the biggest extinction seen in the history of Earth.” (http://palaeo.gly.bris.ac.uk/Palaeofiles/Permian/pangea.html)

19. http://palaeo.gly.bris.ac.uk/Palaeofiles/Permian/pangea.html http://www.geocities.com/earthhistory/permo.htm http://www.earth.rochester.edu/ees207/Mass_Ext/higgins_mass4.html http://www.pbs.org/wgbh/nova/sciencenow/3318/01.html Benton. "How to kill(almost) all life: the end-Permian extinction event." Trends in Ecology 18.7 (2003): 358. Berner. "Examination of hypotheses for the Permo-Triassic boundary extinction by carbon cycle modeling." Proceedings of the National Academy of Sciences 99.7 (2002): 4172. Kidder, David L. and Thomas R. Worsley. "Causes and consequences of extreme Permo-Triassic warming to globally equable climate and relation to the Permo-Triassic extinction and recovery." Palaeogeography, Palaeoclimatology, Palaeoecology 203.3-4 (2004), 207-237. Bibliography