An order of marine mammals that comprises the whales, dolphins, and porpoises. These have a streamlined hairless body, no hindlimbs, a horizontal tail fin, and a blowhole on top of the head for breathing.
- ‘The order Sirenia is composed of manatees and dugongs, and the order Cetacea includes whales, dolphins, and porpoises.’
- ‘However, in a phylogenetic analysis of the complete mitochondrial genome of the Jamaican fruit bat it appeared more closely related to cetferungulates, a clade including Cetacea, Artiodactyla, Perissodactyla, and Carnivora.’
- ‘The order Cetacea comprises two extant sub-orders and one extinct sub-order.’
- ‘They found that the hypothesis that a monophyletic Mesonychia is the sister taxon of Cetacea, and a monophyletic Artiodactyla is the extant sister taxon of Cetacea was significantly congruent with the stratigraphic record.’
- ‘The Cetacea are one of the most distinctive and highly specialized orders of mammals.’
Modern Latin (plural), from Latin cetus, from Greek kētos ‘whale’.