Superfamily Delphinoidea
The Dolphin is the largest and most diverse family of cetaceans. It contains 26 recognised species and 6 toothed whales. Most forms of this family have functional teeth in both jaws, a melon with a distinct beak, smooth sloping foreheads, a single notch in the middle of their flukes and a dorsal fin.
The Monodontidae Family
This is a small family consisting of 2 medium-sized gregarious whales the Narwhal and the Beluga. They are locally common and sometimes travel or feed together. Many taxonomists include the Irrawaddy Dolphin in this family and in some ways it is the tropical equal to the Beluga.