Permian

The Permian period was a time of significant evolutionary advances, particularly for reptiles. The Synapsids, a group of reptiles that includes the ancestors of mammals, diversified during this time. One of the most notable synapsids was Dimetrodon, a predatory reptile with a large sail-like structure on its back. Reptiles became the dominant terrestrial vertebrates during the Permian, largely due to their ability to thrive in the increasingly arid conditions as the climate of Pangaea became drier.

The formation of Pangaea during the Permian dramatically altered the planet’s climate and ecosystems. The interior of the supercontinent experienced extreme temperature variations, with hot, dry deserts forming in many areas, while coastal regions remained more temperate. This aridification led to the decline of the lush swamp forests that had dominated the Carboniferous, and many plant species adapted to drier climates.

Toward the end of the Permian, Earth experienced its most severe mass extinction event, the Permian-Triassic extinction, also known as the “Great Dying.” This event, which occurred around 252 million years ago, was likely caused by a combination of factors, including massive volcanic eruptions in the Siberian Traps, climate change, ocean acidification, and anoxia (lack of oxygen in the oceans). The extinction decimated marine life, including the complete collapse of coral reef ecosystems, and had profound effects on terrestrial life, wiping out many amphibians, reptiles, and plant species.