4/13/2023 0 Comments Ran world gsThe fossil record confirms that species far from the equator suffered most during the event. The fossil record shows where species were before the extinction, and which were wiped out completely or restricted to a fraction of their former habitat. To test this prediction, Payne and co-author Erik Sperling, an assistant professor of geological sciences at Stanford Earth, analyzed late-Permian fossil distributions from the Paleobiology Database, a virtual archive of published fossil collections. That earlier study shows how warmer oceans push animals away from the tropics. The study builds on previous work led by Deutsch showing that as oceans warm, marine animals' metabolism speeds up, meaning they require more oxygen, while warmer water holds less. (Image credit: Justin Penn and Curtis Deutsch, University of Washington) The images below the line represent some of the 96 percent of marine species that died during the event. At the top is the supercontinent Pangaea, with massive volcanic eruptions emitting carbon dioxide. The color of the water shows the temperature change, with red being most severe warming and yellow less warming. A greater percentage of marine animals survived in the tropics than at the poles. ![]() This illustration shows the percentage of marine animals that went extinct at the end of the Permian era by latitude, from the model (black line) and from the fossil record (blue dots). Many species that lived in the tropics also went extinct in the model, but it predicts that high-latitude species, especially those with high oxygen demands, were nearly completely wiped out. "Very few marine organisms stayed in the same habitats they were living in – it was either flee or perish," said second author Curtis Deutsch, a UW associate professor of oceanography.Īccording to study co-author Jonathan Payne, a professor of geological sciences at Stanford’s School of Earth, Energy & Environmental Sciences (Stanford Earth), “The conventional wisdom in the paleontological community has been that the Permian extinction was especially severe in tropical waters.” Yet the model shows the hardest hit were organisms most sensitive to oxygen found far from the tropics. The researchers then combined the species' traits with the paleoclimate simulations to predict the geography of the extinction. The tolerance of modern animals to high temperature and low oxygen is expected to be similar to Permian animals because they had evolved under similar environmental conditions. To analyze the effects on marine species, the researchers considered the varying oxygen and temperature sensitivities of 61 modern marine species – including crustaceans, fish, shellfish, corals and sharks – using published lab measurements. About half the oceans' seafloor, mostly at deeper depths, became completely oxygen-free. Oceans lost about 80 percent of their oxygen. The model reproduces the resulting dramatic changes in the oceans. The researchers then raised greenhouse gases in the model to the level required to make tropical ocean temperatures at the surface some 10 degrees Celsius (20 degrees Fahrenheit) higher, matching conditions at that time. Before ongoing volcanic eruptions in Siberia created a greenhouse-gas planet, oceans had temperatures and oxygen levels similar to today's. ![]() Researchers ran a climate model with Earth's configuration during the Permian, when the land masses were combined in the supercontinent of Pangaea. "This is the first time that we have made a mechanistic prediction about what caused the extinction that can be directly tested with the fossil record, which then allows us to make predictions about the causes of extinction in the future," said first author Justin Penn, a UW doctoral student in oceanography. As temperatures rose and the metabolism of marine animals sped up, the warmer waters could not hold enough oxygen for them to survive. New research from the University of Washington and Stanford University combines models of ocean conditions and animal metabolism with published lab data and paleoceanographic records to show that the Permian mass extinction in the oceans was caused by global warming that left animals unable to breathe. ![]() What has been debated until now is exactly what made the oceans inhospitable to life – the high acidity of the water, metal and sulfide poisoning, a complete lack of oxygen, or simply higher temperatures. Some 96 percent of marine species were wiped out during the "Great Dying," followed by millions of years when life had to multiply and diversify once more. Long before dinosaurs, our planet was populated with plants and animals that were mostly obliterated after a series of massive volcanic eruptions in Siberia.įossils in ancient seafloor rocks display a thriving and diverse marine ecosystem, then a swath of corpses. The largest extinction in Earth's history marked the end of the Permian period, some 252 million years ago.
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