The whales (Cetacea) are a group of mammals who have returned back to the water. Impossible Pictures productions have demonstrated their evolution in a highly detailed way, due to plenty of fossils of the extinct whale species uncovered in the last two centuries or so.
The order Cetacea (/sɨˈteɪʃ(i)ə/) includes the marine mammals commonly known as whales, dolphins, and porpoises. Cetus is Latin and is used in biological names to mean whale. Its original meaning, large sea animal, was more general. It comes from Ancient Greek κῆτος (kētos), meaning whale or "any huge fish or sea monster." In Greek mythology, the monster Perseus defeated was called Ceto, which is depicted by the constellation of Cetus. Cetology is the branch of marine science associated with the study of cetaceans.Fossil evidence suggests that cetaceans share a common ancestor with land-dwelling mammals that began living in marine environments around 50 MYA. Today, they are the mammals best adapted to aquatic life. The body of a cetacean is fusiform (spindle-shaped). The forelimbs are modified into flippers. The tiny hindlimbs are vestigial; they do not attach to the backbone and are hidden within the body. The tail has horizontal flukes. Cetaceans are nearly hairless, and are insulated from the cooler water they inhabit by a thick layer of blubber.
Some species are noted for their high intelligence. At the 2012 meeting in Vancouver, Canada, the American Association for the Advancement of Science (the world's largest science conference), support was reiterated for a cetacean bill of rights, listing cetaceans as non-human persons.
Appearance in the programmesEdit
Ambulocetus, featured in the first episode of Walking with Beasts, was a transitional species. It was built like an otter with a crocodile-like head, and it hunted other animals along the river banks and underwater. In the episode, the ambulocetus met its doom during an underwater gas eruption, which killed both it and other animals by suffocation. The episode ends with a hook to the next episode, however, which is centered around another prehistoric whale - Basilosaurus.Unlike Ambulocetus featured in the previous episode, Basilosaurus and its contemporary, Dorudon, were fully aquatic animals, though they still retained their hind flukes (modern whales got rid of them altogether). The "star" of the second episode of Walking with Beasts, the female Basilosaurus was shown as the apex predator of the ocean, hunting sharks, Dorudon young and even the aquatic Moeritherium (with a varied degree of success). By the end of the episode, it had succeeded in giving birth to its single young, but the episode ends on a more pessimistic note: it talks about the minor extinction event during the Oligocene, that the whales as a group will pull through, but the Archaeoceti (the ancient whales such as Basilosaurus and Dorudon) as a group will not.
After the second episode, Walking with Beasts did not feature any more extinct whales, but both Basilosaurus and Dorudon returned in the second episode of Sea Monsters. Neither whale was featured in such a detail as it had been in Walking with Beasts, though. Dorudon just had a cameo (to compare them with Basilosaurus) and Basilosaurus itself, while shown as perhaps the fourth most deadliest sea monster of all times, was shown to just attack a speaker that Nigel Marvin's crew had put underwater to lure it.
The second half of that episode had the final prehistoric whale that Impossible Pictures have shown up to date - the Odobenocetops. It was much smaller than the earlier Basilosaurus, and was built more like a manatee or a walrus than a regular dolphin. It had a pair of mismatched tusks that were used either in fights for females or to dig up clams and other shellfish, and was prey of a much larger prehistoric shark - Megalodon, or rather the shark's juveniles. Odobenocetops flourished during the first half of the Pliocene time period but died out without leaving any descendants in the present.