Image 1 (IMAGE) University of Bristol Caption The first lizards and snakes evolved slowly, but eventually became much more diverse than their close relatives, the rhynchocephalians, which initially showed fast evolution. Today there are 10,000 species of squamates, but only 1 of rhynchocephalians. Credit Dr Tom Stubbs Usage Restrictions once with release License Licensed 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.