Dinosaurs Evolved Rapidly After First Relatives Appeared

The first dinosaur relatives may have emerged up to 10 million years later than thought, then evolved rapidly to rule the world.

December 8, 2015
8:50 AM EST
Shown is an artist's impression of animals that lived 235 million years ago in northwestern Argentina. Fossils found in this region include ancient mammal relatives Dinodontosaurus (left background) and early dinosaur relatives Lewisuchus (right background) and Lagerpeton (right foreground). | Victor Leshyk