Hadrosaurid Tooth Microstructure (image) American Museum of Natural History Caption This cross-section of a duck-billed dinosaur tooth (Edmontosaurus) shows the remarkably complex architecture. Six main tissues compose the tooth, where most reptiles only have two (enamel and orthodentine). Like horse, bison, and elephant teeth, the myriad of tissues--each with their own unique wear attributes--allowed the teeth to self-wear with use to form complex grinding surfaces. These dinosaurs possessed among the most sophisticated teeth known. Credit G. M. Erickson/Florida State University Usage Restrictions Can be used with appropriate credit 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.