The Rise and Fall of the Dinosaurs: A New History of a Lost World: The Definitive Dinosaur Encyclopedia with Stunning Illustrations, Embark on a Prehistoric Quest!

by Steve Brusatte

The fall of these herbivores gave the plant-eating primitive sauropod cousins like Panphagia and Saturnalia an opportunity to seize a new niche in some ecosystems.

Failure of incumbents opened up an opportunity