During the Permian, the continents were all assembled into a single mass, Pangea, and the planet experienced a strong variation in very contrasting climates with a sometimes tropical and humid environment, especially near the equator, but generally warmer and drier with many deserts.
These variations have favored the development of mammalian amphibians and reptiles.
One of the best known species is Eryops, a robust and exceptional amphibian due to its entirely bony skeleton, which has favored its conservation.
It was a formidable predator, the alligator of ancient times.
But there was an even more formidable predator, Dimetrodon, who reigned supreme over his lands. A meat-eating predator with a huge sail on its back. Scientists believe the huge sail may have been used to help Dimetrodon warm up faster in the morning. This allowed it to feed on other rainforest animals before they got up and got going.
These species, also called therapsids, gave birth to mammals, which are in a way our ancestors.