Dinosaur (IMAGE) University of Birmingham Caption Ecological changes following intense volcanic activity during the Carnian Pluvial Episode 230 million years ago paved the way for dinosaurs to become the dominant species. Credit Pixabay Usage Restrictions No restrictions. License Public Domain Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.