Like the better-known end-Permian extinction, the end-Triassic event may have been a result of global climate change. 
When did it happen?
The extinction occurred near the end of the Triassic Period, about 201 million years ago.
Who became extinct?
All major groups of marine invertebrates survived the extinction, although most suffered losses. Brachiopods, shelled cephalopods, sponges and corals were particularly hard hit. On land, casualties included the phytosaurs, a group of crocodile-like animals.
What caused the extinction?
At the end of the Triassic, the supercontinent of Pangea, which combined all of the modern continents into a single landmass, began to break (rift) apart. As North America separated from Africa and the Atlantic Ocean began to form, volcanic activity on a massive scale introduced carbon dioxide into the atmosphere. This led to global warming and changes to the oceans that were similar to (although not as large) those that occurred at the end-Permian extinction.
All of today’s continents were combined into the supercontinent of Pangea. Pangea was beginning to break apart. As North America and Africa began to separate there was a vast outpouring of lava. The area of volcanic rocks that formed at this time is shown in yellow. Gases, including carbon dioxide, produced during the eruptions led to global climate change.
