THE END-TRIASSIC MASS EXTINCTION RANKS AS ONE OF THE FIVE BIGGEST MASS EXTINCTION EVENTS IN EARTH’S HISTORY

The end-Triassic mass extinction ranks as one of the five biggest mass extinction events in Earth’s history. The extinction had a devastating effect on marine life, especially corals, which had an extinction rate of at least 96% or more. Reefs collapsed and coral taxa suffered major losses. Here we explore the selectivity of extinction and recovery among scleractinian corals and hypothesize that more specialized corals preferentially were selected for extinction. Corals with higher integration states today are generally more specialized to their environments, therefore coral integration among fossils was an excellent way to test our hypothesis. We assigned numbers to different coral integrations from 1 to 10 (least integrated to most integrated) to compare the frequency of coral integration before and after the mass extinction. Using this method, we conducted an analysis of the Paleobiology database as well as of physical specimens from the University of Montana Paleontology Center. Our study confirms our hypothesis and shows a great loss in highly integrated corals after the end-Triassic mass extinction which likely also correlates with photosymbiosis and reef building. By understanding how corals reacted to their environments in the past, the more we may understand the modern coral crisis and ways to prevent it.