About 250 million years ago, at the end of the Permian period, something killed some 90 percent of the planet's species. Less than 5 percent of the animal ... laid down during the extinction.

However, even the trilobites' evolution could not help the trilobites escape the Permian Period, where there was a mass extinction of animals on Earth. During the Permian Period, there was massive ...

Learn more about a time period marked ... of all prehistoric animals. More than 17,000 species are known to have survived until the mega-extinction that ended the Permian period 251 million ...

The period of time before the Triassic was called the Permian. This was a time when a wide variety of animals lived ... About 200 million years ago, during a period known as the Triassic-Jurassic ...

Life in the Triassic period had a rough start. In the Permian ... a dog-sized animal that looked like a cross between a pig and a lizard. These evolved land reptiles thrived during the periods ...