Rodent Molars (IMAGE) Cell Press Caption This is the skull of a Laotian rock rat. Over evolutionary time, rodent molars have become taller. Credit Vagan Tapaltsyan and Ophir Klein Usage Restrictions Credit Required. 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.