The end of the Triassic period, 201 million years ago, is considered one of the greatest mass extinction events in the history of the Earth. The main cause of this catastrophe for life and evolution is thought to have been intense volcanism in Siberia. This led to worldwide climatic turbulence and acidification of the sea water.
Click here for original story, More nautilids may have survived the mass extinction at the end of the Triassic period than previously thought
Source: Phys.org