Bottlenose Dolphin Skull (IMAGE) Smithsonian Caption The skull of a bottlenose dolphin rests atop shell accumulations on an island of the Colorado River delta, Baja California, Mexico. Credit Nicholas Pyenson, Smithsonian Institution Usage Restrictions Please include photo credit information when using this image. 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.