How are cetaceans considered mammals

Cetaceans are mammals that have adapted to aquatic life and live exclusively in the water. The term Cetacea in biological terms means whale or (originally) large sea animal. There are three types of marine mammals that compose the cetacean species which include whales, dolphins and porpoises.

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Explanation: Whales are mammals because they give birth to live young, they have fur (although it is very sparse on their body), they have lungs and breath air and they provide milk for their young. Answer 3: ... Dolphins and other whales are all mammals called cetaceans.