Pterosaur evolutionary tree (IMAGE) University of Leicester Caption This evolutionary tree illustrates the remarkable transformation of pterosaur hands as they adapted from a climbing lifestyle to one suited for terrestrial movement. Early, long-tailed pterosaurs, which relied on climbing, were limited to smaller body sizes. In contrast, later, short-tailed species that adapted to walking on land were free to grow larger, enabling some to reach giant sizes. Credit Artist credit: Rudolf Hima Usage Restrictions Use only with 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.