Elephant Shark (image) Max-Planck-Gesellschaft Caption The immune system of the elephant shark is simpler than many other vertebrates studied so far. The present studies also explain, why cartilaginous fishes do not generate human-like bones. Credit Fir0002/Flagstaffotos Usage Restrictions None 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.