Lower jaw bone of manatee (IMAGE) University of Texas at Austin Caption A manatee lower jaw fossil. Its S-shaped curve is a distinctive manatee trait. Scale bar is 2 centimeters. Credit Bell et al. Usage Restrictions Credit 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.