The Dolphin is one of the most intelligent creatures alive in the entire world. Surprisingly there are over 40 extant species of dolphins alive today with a population of around 600,000! The reason for there being so many species of dolphins is because the general term Dolphin refers to the species in the Delphinidae, Platanistidae, Iniidae, Pontoporiidae, and the extinct Lipotidae families. Dolphins are characterized by their smooth skin that is colored in black, grey, or white pigments. They have a blowhole on the top of their head that they use for breathing and have a flipper that moves up in down like a whale.
You may think that the Dolphin is closely related to many fish in the ocean but, they are more closely related to humans than fish. The Dolphin is a mammal which means that it evolved from something that lived on land. It is thought that the Dolphin evolved from the Pakicetus, a four legged mammal that dates back to 50 million years ago.