Evolution Permian-Triassic Extinction

One of the most dramatic and mysterious events in the history of life, the so-called "Great Dying" of animals and plants some 250 million years ago, continues to fascinate and baffle scientists. Of the five or so mass extinctions recorded in Earth's fossils, this one at the end of the Permian period and the start of the Triassic was the most catastrophic.

More than half of the families of living things died out, and as many as 90 to 96 percent of the planet's marine species were lost. At the same time, perhaps 70 percent of the land's reptile, amphibian, insect, and plants species went extinct.