My favorite mammal is a dolphin! There are so many kinds of dolphins that are widely distributed around the world!
Fun! I once seen a pack of porpoises while boating. I think they're in the same family as dolphins?  
Yes they are! There are actually 40 species of dolphins to be exact!
Wow, have you seen many different kinds?
Dolphin
Dolphin is a common name of aquatic mammals within the infraorder Cetacea. The term dolphin usually refers to the extant families Delphinidae (the oceanic dolphins), Platanistidae (the Indian river dolphins), Iniidae (the New World river dolphins), and Pontoporiidae (the brackish dolphins), and the extinct Lipotidae (baiji or Chinese river dolphin). There are 40 extant species named as dolphins.
Dolphins range in size from the long and Maui's dolphin to the and killer whale. Several species exhibit sexual dimorphism
Oceanic dolphin
Oceanic dolphins or Delphinidae are a widely distributed family of dolphins that live in the sea. Thirty extant species are described. They include several big species whose common names contain "whale" rather than "dolphin", such as the killer whale and the pilot whales. Delphinidae is a family within the superfamily Delphinoidea, which also includes the porpoises (Phocoenidae) and the Monodontidae (beluga whale and narwhal). River dolphins are relatives of the Delphinoidea.
Oceanic dolphins range in size from the -long and Maui