Toothed whale porpoise as a fish. Toothed whales, as well as baleen whales, are descendants of land-dwelling mammals of the artiodactyl order (even-toed ungulates). They are closely related to the hippopotamus, sharing a common ancestor that lived around 54 million years ago (mya). The primitive cetaceans, or archaeocetes, first took to the sea approximately 49 mya and became fully aquatic by 5–10 million years later. The adaptation of echolocation and enhanced fat synthesis in blubber occurred when toothed whales split apart from baleen whales, and distinguishes modern toothed whales from fully aquatic archaeocetes. This happened around 34 mya. Unlike toothed whales, baleen
Children of the Whales Children of the Whales The story focuses on a boy called Chakuro, who lives on a giant vessel called a Mud Whale that drifts over the sea of sand. In the Mud Whale, society is divided into two kinds of people: the Marked, who can move objects with their minds using a strange power called "thymia", at the expense of shortened lifespans, and the Unmarked, people who lack thymia but enjoy longer lifespans. Chakuro and his friends have never seen anyone from the outside world, and they spend their days yearning to explore and learn about it. In year 93