It’s the end of the world as they knew it
The Permian period began with lush forests. new bugs arrived to feed on the succulent plants, strange sharks still swam the seas, and the first large plant eaters and their predators walked the increasingly dry earth. At the end of the period was the most devastating mass extinction in our planets history.
Here are a couple of videos about the Permian period and the dimetrodon.
Here are a couple of articles about the Permian period, and the mass extinction event that ended it.