List of aquatic mammals group

Proboscidea
Proboscidea are a taxonomic order of afrotherian mammals containing one living family (Elephantidae) and several extinct families. This order, first described by J. Illiger in 1811, encompasses the trunked mammals. In addition to their enormous size, later proboscideans are distinguished by tusks and long, muscular trunks; these features were less developed or absent in the smaller early proboscideans.

Cetacea
Cetaceans are aquatic mammals constituting the infraorder Cetacea. There are around 89 living species, which are divided into two parvorders. The first is the Odontoceti, the toothed whales, which consist of around 70 species, including the dolphin, porpoise, beluga whale, narwhal, sperm whale, and beaked whale. The second is the Mysticeti, the baleen whales, which have a filter-feeder system, and consist of fifteen species divided into three families, and include the blue whale, right whale, bowhead whale, rorqual, and gray whale.