Dolphins, manatees, and sea lions are all aquatic mammals but are not closely related taxonomically. All three species are marine mammals, meaning they spend part or all of their lives in the sea and contiguous bodies of water. Dolphins belong to the taxonomic order Cetacea, which includes whales, dolphins, and porpoises. Manatees (sea cows), however, belong to the order Sirenia, which also includes the dugong. Sea lions were once placed in the order Pinnipedia, with seals, but now belong to the order Carnivora with bears, dogs, and raccoons. Even though these species at first glance may seem similar, the way they are classified shows that each has very different characteristics and abilities. The specific characteristics and abilities are outlined in this article.