The Hippopotamases, Whales, Dolphins & Porpoises (Cetartiodactyla)
(Whippomorpha) - suborder
The Hippopotamuses
(Hippopotamidae)
- family
The (Archaeoceti) - suborder -extinct-

(Pakicetidae)
- family

(Ambulocetidae)
- family

(Remingtonocetidae)
- family

(Protocetidae)
- family

(Basilosauridae)
- family

(Kekenodontidae)
- family
The Whales, Dolphins & Porposes (Cetacea) - infrarder
The Baleen Whales (Mysticeti) - parvorder
The Right Whales
(Balaenidae)
- family
The Rorquals
(Balaenopteridae)
- family
The Pygmy Right Whale
(Cetotheriidae)
- family

(Eschrichtiidae)
- family
The Toothed Whales (Odontoceti) - parvorder
The (Delphinoidea) - superfamily
The Oceanic Dolphins
(Delphinidae)
- family

(Monodontidae)
- family
The Porpoises
(Phocoenidae)
- family
The (Inioidea) - superfamily

(Iniidae)
- family

(Pontoporiidae)
- family
The (Platanistoidea) - superfamily

(Platanistidae)
- family

(Squalodontidae)
- family
The (Lipotoidea) - superfamily

(Lipotidae)
- family
The (Physeteroidea) - superfamily

(Kogiidae)
- family

(Physeteridae)
- family
The (Ziphioidea) - superfamily

(Ziphidae)
- family