Triassic Period
252-201 million years ago
The Triassic Period is when dinosaurs first appeared on Earth. After the biggest mass extinction in history wiped out nearly 96% of all species, life slowly rebuilt itself â and dinosaurs emerged as one of the survivors. Early Triassic dinosaurs were small compared to what came later, but they were the ancestors of everything that followed.
Fun Facts
- âThe Triassic Period started right after the Permian-Triassic extinction, the worst mass extinction in Earth's history.
- âEarth had one giant supercontinent during the Triassic called Pangaea. There were no separate continents yet.
- âThe earliest known dinosaurs appeared about 230-240 million years ago during the Late Triassic.
- âTriassic dinosaurs were much smaller than later giants. Many were no bigger than a modern turkey.
- âThe first mammals also appeared during the Triassic Period, though they were tiny and looked like shrews.