This skeleton is part of the Mississippi State University College of Veterinary Medicine's Anatomy Collection:

Bottlenose dolphins are the official state water mammal of Mississippi and common residents off the Gulf Coast of Mississippi.  The dolphin’s streamlined shape and complex body musculature move the horizontally-oriented caudal (tail) fin, or fluke, in an up and down motion typical of marine mammals.  Fish, in comparison, have a vertically-oriented tail that is moved in a side to side motion.  Dolphins are superior swimmers capable of speeds up to 21 knots (approximately 24 mph).