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 in the seas survived. On land ...

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 ...

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 ...

The Permian period’s mass extinction had wiped out ... At first, these creatures were much smaller, but they eventually outgrew other animals such as the Lystrosaurus, a dog-sized animal that ...