The 5 Mass Extinctions That Have Swept Our Planet

The End-Permian mass extinction wiped out Synapsids like this one from South Africa. Jonathan Blair works for National Geographic.

You're part of the 1%. Almost all of the 4 billion species that have ever existed are no longer around.

During a mass extinction, many evolutionary family trees were given the ax. The geological blink of an eye can range from thousands to millions of years. Many scientists believe we are in the middle of a sixth mass extinction event because of the data from the fossil record.

The cause of great die-offs is a perfect storm consisting of ocean acidification and land temperatures spiking. Large-scale volcanic activity, spread across an entire region, is usually the cause of these events. Only one space rock has been linked to a mass extinction.

Researchers call mass extinctions End-Cretaceous because they end a geologic period. Mass extinctions can be bad news, but they can also be good news, as surviving species can explode in diversity and territory.

1. End-Ordovician: The 1-2 Punch