Bird brain comparison graphic (IMAGE) University of Texas at Austin Caption The ancestors of living birds had a brain shape much different from other dinosaurs (including other early birds). This suggests that brain differences may have affected survival during the mass extinction that wiped out all nonavian dinosaurs. Credit Christopher Torres / The University of Texas at Austin Usage Restrictions Include photo credit License Original content 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.