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 species ... But most life is concentrated ...

Hundreds of millions of years ago as life on Earth was beginning ... where there was a mass extinction of animals on Earth. During the Permian Period, there was massive global warming.

The period of time before the Triassic was called the Permian. This was a time when a wide variety of animals lived, including a group of animals called the synapsids, which would later evolve ...

Learn more about a time period marked by an intense burst ... The Cambrian Explosion saw an incredible diversity of life emerge, including many major animal groups alive today.

Life in the Triassic period had a rough start. In the Permian period before ... but they eventually outgrew other animals such as the Lystrosaurus, a dog-sized animal that looked like a cross ...