Cetacea is an infraorder that comprises the 94 species of whales, dolphins, and porpoises. It is divided into toothed whales (Odontoceti) and baleen whales (Mysticeti), which diverged from each other in the Eocene some 50 million years ago (mya).

Cetaceans are fully aquatic mammals belonging to the order Artiodactyla and branched off from other artiodactyls around 50 mya. Cetaceans are thought to have evolved during the Eocene (56-34 mya), the second epoch of the present-extending Cenozoic Era.

Cetaceans (order Cetacea) are an entirely aquatic order of mammals comprising the whales, the dolphins, and the porpoises. The ancient Greeks recognized that cetaceans breathe air, give birth to live young, produce milk, and have hair—all features of mammals.

2024年12月21日 · cetacean, (order Cetacea), any member of an entirely aquatic group of mammals commonly known as whales, dolphins, and porpoises. The ancient Greeks recognized that cetaceans breathe air, give birth to live young, produce milk, and have hair—all features of …

Cetacea (/ s ɪ ˈ t eɪ ʃ ə /; from Latin cetus 'whale', from Ancient Greek κῆτος () 'huge fish, sea monster') [3] is an infraorder of aquatic mammals belonging to the order Artiodactyla that includes whales, dolphins and porpoises.Key characteristics are their fully aquatic lifestyle, streamlined body shape, often large size and exclusively carnivorous diet.

2023年8月2日 · Cetaceans are a group (Cetacea) of marine mammals comprising all whales, dolphins and porpoises. On this page you’ll find out what cetaceans are, cetacean characteristics, the different types of cetaceans, and examples of cetaceans...

2024年7月30日 · Cetacean animals are lung mammals that inhabit our seas and oceans, although there are also some species live in rivers. For more, we suggest taking a look at our aquatic mammals list.

2024年12月26日 · The Society for Marine Mammalogy’s (SMM) Committee on Taxonomy, chaired by Ana Costa (who took over from Patty Rosel in 2024), produces the official list of marine mammal species and subspecies. The IUCN Cetacean Specialist Group follows the SMM list including when identifying taxonomic units to be assessed for the Red List.

There are five cetacean species and 19 subspecies or subpopulations of cetacean that are currently classified as Critically Endangered on the IUCN Red List. The Yangtze River dolphin (Lipotes vexillifer) is classified as critically endangered and may already be functionally extinct.

There are at least 83 living species of cetaceans, with 46 genera in 14 families. Of the two extant suborders, Odontoceti is larger and more diverse, with at least 70 species, 40 genera, and 10 families.