Tracing Millions of Years of Megatooth Shark Evolution (image) Florida Museum of Natural History Share Print E-Mail Caption These three teeth depict more than 50 million years of megatooth shark evolution. Megalodon's earliest ancestor, Otodus obliquus, from left, had smooth-edged teeth with a thick root and lateral cusplets, two "mini-teeth" flanking the main tooth. Another ancestor, Carcharocles auriculatus, had serrated teeth with lateral cusplets. Carcharocles megalodon had flattened bladelike teeth with uniform serrations and no cusplets. Credit Florida Museum photo by Kristen Grace Usage Restrictions Please credit Kristen Grace/Florida Museum Share Print E-Mail 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.