Pages • 2
The Triassic-Jurassic Essay Preview: The Triassic-Jurassic Report this essay The Triassic-Jurassic Boundary Extinction There have been five major extinction events in geologic history. The largest of which was the Permian-Triassic extinction that occurred approximately 251 million years ago. During this extinction, 96% of marine species and 70% of terrestrial vertebrate species went extinct. Other extinction.