Great Dying

Great Dying
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Name	Great Dying
Period	Permian–Triassic boundary
Caption	Extinction event at the Permian–Triassic boundary
Location	Siberia, Tethys Ocean, Pangea
Date	~252 million years ago
Casualties	estimated >90% marine species, ~70% terrestrial vertebrate species

Great Dying The Great Dying was the most severe mass extinction in Earth's history, occurring at the Permian–Triassic boundary and profoundly affecting life on land and in the oceans. It coincided with dramatic tectonic, volcanic, climatic, and geochemical upheavals involving regions such as Siberia, ocean basins like the Tethys Ocean, and supercontinents including Pangea, and has been studied by researchers affiliated with institutions such as the Smithsonian Institution, University of Cambridge, and California Institute of Technology.

Overview

The extinction event at the Permian–Triassic boundary led to catastrophic losses among faunas recorded in fossil assemblages from sites like the Karoo Basin, Meishan, and Guadalupian formations, and reshaped subsequent evolutionary radiations involving groups represented in collections at the Natural History Museum, London, American Museum of Natural History, and Field Museum of Natural History. Paleontologists such as Charles Doolittle Walcott, Alfred Wegener-era geologists, and modern researchers at universities including Harvard University, Yale University, and University of Tokyo have debated timing and mechanisms using biostratigraphy, geochronology, and comparative anatomy preserved in repositories like the Royal Society archives and publications in journals like Nature and Science.

Causes

Hypotheses for proximate and ultimate drivers include massive volcanism from the Siberian Traps flood basalts, large-scale methane release from clathrate reservoirs linked to warming episodes similar to those studied by teams at Woods Hole Oceanographic Institution and Lamont–Doherty Earth Observatory, and perturbations to ocean chemistry such as euxinia recorded in studies by researchers at the Geological Society of America and American Geophysical Union. Additional proposed contributors include bolide impacts akin to the Chicxulub crater scenario examined by scientists at the University of Arizona, runaway greenhouse feedbacks discussed by modelers at NASA Goddard Institute for Space Studies and acidic weathering interpreted by geochemists at the Max Planck Institute for Chemistry. Interactions among volcanism, ocean anoxia, greenhouse warming, and carbon cycle disruption have been explored in collaborative projects involving MIT, Stanford University, and ETH Zurich.

Extent and Environmental Impact

Biodiversity collapse affected marine invertebrates visible in fossil collections at the Smithsonian Institution and terrestrial vertebrates represented in the Royal Ontario Museum; reef ecosystems including those studied in Zechstein deposits, pelagic communities documented from the Panthalassa realm, and terrestrial floras across Laurasia and Gondwana experienced profound turnover. Geochemical proxies such as carbon isotopes analyzed at Columbia University, sulfur isotopes measured at University of California, Santa Cruz, and mercury anomalies studied by teams at the University of Bristol indicate global carbon cycle upheaval, ocean redox shifts, and atmospheric perturbations that led to habitat loss, acidification, and hypoxia affecting stratified basins like the Permian Basin and shallow shelves such as those preserved in Zechstein Sea deposits.

Biological Recovery and Aftermath

Post-extinction recovery involved delayed and stepwise radiations of groups including archosauriforms whose early representatives are curated at Smithsonian Institution National Museum of Natural History, synapsids catalogued in Field Museum of Natural History collections, and marine clades such as ammonoids and bivalves documented in the Natural History Museum, London. The restructuring of ecosystems opened ecological space exploited by later radiations leading to Mesozoic dominance by taxa studied by paleobiologists at University of California, Berkeley, University of Chicago, and University of California, Los Angeles, with recovery intervals constrained through geochronology conducted at Oak Ridge National Laboratory and isotopic work at Argonne National Laboratory.

Evidence and Research Methods

Evidence for timing and mechanisms derives from radiometric dating techniques such as U-Pb zircon geochronology performed at European Centre for Geodynamics and Seismology and magnetostratigraphy applied by teams at University of Oxford, coupled with biostratigraphic correlations using index fossils archived at institutions like the Paleobiology Database. Geochemical analyses including carbon and oxygen isotope work at Scripps Institution of Oceanography, trace metal concentrations measured at ETH Zurich, and sedimentological studies from research groups at University of Leeds and University of Melbourne provide multiproxy reconstructions. Experimental and modeling approaches from centers such as Princeton University, Imperial College London, and Carnegie Institution for Science integrate climate models, ecosystem simulations, and laboratory experiments on acidification and anoxia.

Historical and Cultural Interpretation

Interpretation of the event has involved historical figures and institutions like Georges Cuvier-influenced comparative anatomists and modern synthesis proponents publishing in venues such as Proceedings of the Royal Society and Philosophical Transactions of the Royal Society. Public and cultural engagement through museum exhibitions at the Natural History Museum, London, documentaries produced by broadcasters such as the BBC and National Geographic, and outreach by universities including Oxford University and University of Cambridge have shaped understanding of Earth's deep-time crises and influenced contemporary discussions on anthropogenic change addressed in policy forums like the Intergovernmental Panel on Climate Change.

Category:Mass extinctions