Delphinus
At first it was thought that there was only one species of the Delphinus genus, the Short-beaked Common Dolphin (Delphinus Delphis). But later, studies showed that there was another species, the Long-beaked Common Dolphin (Delphinus Capensis). The difference between the Short-beaked Common Dolphin and the Long-beaked Common Dolphin, is that the Short-beaked Common Dolphin is smaller in size and has a smaller beak than the Long-beaked Common Dolphin. Now scientist say there is a third species, the Arabian Common Dolphin (Delphinus Tropicalis) which has a long, thin beak and lives in the Red Sea and the Indian Ocean, but it is not confirmed.