A mass extinction is when big percentage of all species die off. The best-known mass extinction is probably the one that ...

These first steps toward life on land were cut short by the freezing conditions that gripped the planet toward the end of the Ordovician. This resulted in the second largest mass extinction of all ...

Abrupt climate change at the end of the Ordovician Period (~450-440 million years ago) caused the second largest mass extinction in Earth history, including the demise of the trilobite ...

It caused changes that wiped out about 75% of all living things. But the first major mass extinction was way before that—about 443 million years ago. It’s called the Late Ordovician mass extinction.

Emma Bernard, a curator of fossil fish at the Museum, says, 'Shark-like scales from the Late Ordovician have been found ... The Carboniferous Period (which began 359 million years ago) is known as the ...

But first there was a period of biological regrouping following the disastrous climax to the Ordovician ... drew to a close with a series of extinction events linked to climate change; however ...