The extinction caused changes in marine organisms and brought about new, mobile marine organisms. "The changes occurred during an interval of severe climatic, tectonic, and geophysical changes and marked geochemical shifts" (Erwin, 69). In Richard Kerr's article, The Great Extinction Gets Greater, there is a quote from Erwin, "the organisms you see in a tide pool today are a consequence of" the Permo-Triassic extinction (Kerr, 1370). Therefore, if the extinction had not have taken place, there would be a whole different set of organisms that we would see around today.
According to Steven Stanley, the author of Earth System History, there were two extinctions. The First Extinction and the Terminal Extinction. He wrote that the First .
Extinction was probably caused by a glacial event that led to changes within the climate. The second, Terminal Extinction has several possibilities for causes. They include atmospheric carbon, flood basalts near Sibera, decline in sea level, and a sudden extinction, one that happened in less than one million years. "There was no single cause of this extinction; rather, a series of physical events culminated in a progressive biotic collapse (Erwin, 87).
Stanley wrote that it is possible that the extinction happened within one million .
years which disagrees with Erwin's argument that the extinction lasted five to eight million years. Georgina Hickey with co-author of Mother of Mass Extinctions, Abbie Thomas also stated in their article that in took less than one million years for the .
extinction to take place. Therefore the amount of time the extinction took is in disagreement among authors with theories as to the cause of the End-Permian mass extinction.
Authors Paul Wignall and Richard Twitchett, believe that the extinction was caused by oceanic anoxia. They suggest that while the theory of eruption suddenly of basalts in Siberia may have also caused the extinction, they have done research that suggests that oceanic anoxia is the cause.
