triassic

Dinosaurs did not exist in a single monolithic era. They ruled Earth across three distinct geological periods spanning 165 million years — longer than the time separating us from the last non-avian dinosaur. Each period had its own continents, climates, ecosystems, and dominant species. Understanding what changed across the Triassic, Jurassic, and Cretaceous is the key to understanding why dinosaurs became what they became.

Dinosaurs did not begin as rulers. They spent the first 30 million years of their existence as minor players in ecosystems dominated by other animals, squeezed into a world recovering from the most catastrophic extinction in Earth's history. Understanding where dinosaurs came from requires understanding the strange, forgotten world they were born into.