Dolphins (Sotalia) (Delphinus) (Tursiops) and whales {Cetacea} live in ocean and have blubber.
limbs
Forelimbs are fin-like. They have no hind limbs.
respiration
Cetaceans have one or two blowholes on head top.
teeth or baleen
Some Cetacea (Odontocetes) have teeth: sperm, pilot, and beluga whales, and dolphins and porpoises. Some Cetacea (Mysticetes) have baleen: blue and fin whales. Extinct ancestors belong to Archaeocetes.
whales
Sulfur-bottom whale is 150 tons and 35 meters long. Narwhal has long horn. Humpback whale, finback whale, gray whale, and blue whale are other whales.
dolphins
Dolphin has directional sonar, useful up to mile. Porpoise is like dolphin. Orca or killer whale is large dolphin. Dolphins shed soft flaky skin every two hours.
evolution
Cetacea evolved from artiodactyls.
smooth skin, pointed snout, tail flips up and down, makes sounds {dolphin} (Tursiops) (Delphinidae).
rounded forehead, beak, north Atlantic and Mediterranean {bottle-nosed dolphin} (Tursiops).
black and white, largest dolphin {orca} {killer whale}.
smaller than dolphin, blunt snout {porpoise} (Phocaena) (Lagenorhynchus).
Whales {whale, mammal} are baleen or toothed whales.
whale {leviathan}.
small, Arctic whale, male {narwhal} (Monodon monoceros). Male has large long twisted elongated tooth.
largest toothed whale {sperm whale}. Head cavity contains spermaceti and oil.
marine, large, two blowholes, filter feeder {baleen whale} (Mysticeti). Rorqual whales are finback whale, blue whale, and humpback whale. Other whales are gray whale, right whale, and Sei whale. Elastic, horny material makes fringed plates {baleen} {whalebone} down from upper jaws.
baleen whale, arctic {right whale}.
Large marine filter-feeder baleen whales {rorqual whale} include finback whale, blue whale, and humpback whale.
large, baleen whale, rorqual whale {blue whale}.
baleen whale, large, flat head, throat furrows, rorqual whale {finback whale}.
baleen whale, rorqual whale {humpback whale}.
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Date Modified: 2022.0225