Did dolphins' ancestors belong to the same group as rhinoceroses, horses, giraffes?
Dolphins are a big family of animals that have many shapes and sizes. No matter where they are from or what form they take, dolphins have a knack for making sea life funny.
Millions of years ago, dolphins' ancestors had legs and walked on land! All cetaceans - the group includes dolphins and porpoises - are likely descended from a group of meat-eating, hoofed mammals. These ancestors began moving into the sea around 50 million years ago because it contained food.
Over the years, the cetacean family tree branched out from those early ancestors into the main three groups that we see today - dolphins, whales, and porpoises. You can find evidence of modern cetaceans' land-loving origins. Their skeletons contain small, rod-shaped bones near their pelvis. These bones are the remains of hind legs - evolutionary leftovers after millions of years of turning into full-time swimmers.
Dolphins live in every ocean in the world and even in some rivers. Most dolphins live in the warm waters around the Equator.
Dolphins sleep for about eight hours a day, although they never sleep deep. They sleep with only half their brain at a time. The other half stays active can surface to breathe. Their smooth, hairless bodies glide through the water with ease. Dolphins stay warm in cold water with the help of layers of fat under their skin called blubber. A blowhole at the top of their head allows for easy breathing at the water's surface.
Dusky dolphin lives near southern Australia and New Zealand. Every morning they move to deeper waters in search of food.
Dusky Dolphin is one of the most intelligent animal species in the world. It communicates with other individuals using its language with whistles, clicks, and squeaks.

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