Triassic

The Triassic Period, spanning from 252 to 201 million years ago, marked the opening chapter of the Mesozoic Era. It began in the bleak aftermath of the Permian mass extinction, which had wiped out most life on Earth. The planet's landmasses were clustered into a single, vast supercontinent called Pangea, surrounded by an immense ocean named Panthalassa. The interior of Pangea was largely an arid, scorching desert. Life slowly recovered from the extinction crisis, giving rise to the very first true dinosaurs, flying pterosaurs, and early, tiny mammals. In the warming oceans, the first specialized marine reptiles, such as ichthyosaurs, began to evolve. The Triassic Period ended with another major mass extinction event, likely triggered by massive volcanic eruptions as Pangea started to fracture. This die-off cleared away competing reptile groups, allowing dinosaurs to dominate the subsequent Jurassic Period.