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

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

  • Permian-Triassic ExtinctionThe Mother of all ExtinctionsAnne Kleinhenz

  • Permian-Triassic ExtinctionWhat was it?The mass extinction at the end of the Permian that wiped out almost all lifeTook place about 250myaPaleozoic and Mesozoic ErasTook place over a span of 5-10 million years

  • When?5-10 million years is an abnormally long timeMany taxa slowly died out in the beginningTowards the end, extinctions were more rapid

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

  • 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 PermianKilled about 95% species in oceansMarine invertebrates were hit the worst by extinction

  • What Died?All trilobites94% GraptolitesAll Blastoids, Acanthodians, Rugose and Tabulate Corals, Pelycosaurs98% Crinozoans96% Anthozoans96% Brachiopod genera

  • What Else Died?85% Gastropods59% Bivalves 79% Bryozoans90% Gastropod genera and 3 of 16 Gastropod families 97% Ammonoids

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

  • Vertebrates That Died and LivedAmphibians died out as the pools of water in which they lived in dried upAmniota then became dominantBy Mid-Permian the Therapsids became dominantArchosauriformes were also evolving at the time, and were one of the few vertebrates to make it through the extinction and diversify

  • Vascular plantsVascular plants showed no major drop or change in numbersThe fossil record shows a gradual transition from Paleozoic to Mesozoic florasTook place over a period of about 25 million years

  • Why?There are many theories of what caused one of the larges extinctions in history:VolcanismImpactClimate ChangeFormation of PangaeaGlaciationOthers

  • ImpactThere is some evidence supporting this theoryNickel-rich LayersFrom impact or heavy-metal rich mantle-derived lavasShocked quartsBedout Crater in Australia

  • PangaeaFormed during the Late PermianTectonic movement of the plates had many side effectsMost was inland, so weather was hot and dry in low lying areas, and unseasonable weather patterns in higher altitudesMovement of species and more competitionExtreme flooding due to glacial melting and caused reduced land area

  • VolcanismThe Siberian TrapsVolcanoes cover approximately 2,000,000 km2 in Siberia (greater area than Europe)Eruptions lasted at full intensity for about a million years

  • VolcanismThe 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.

  • VolcanismGreenhouse gases warm the climate by allowing sunlight to pass throughHeat 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.

  • Another Volcanic TheoryPBS Nova Special

  • Linked TheoriesThe 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. (

  • Bibliography "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.