Evolution of cetaceans "Caperea marginata") all have derived characteristics presently unknown in any cetothere and vice versa (such as a sagittal crest). The adaptation of echolocation occurred when toothed whales (Odontoceti) split apart from baleen whales, and distinguishes modern toothed whales from fully aquatic archaeocetes. This happened around 34 million years ago in a second cetacean radiation. Modern toothed whales do not rely on their sense of sight, but rather on their sonar to hunt prey. Echolocation also allowed toothed whales to dive deeper in search of food, with light no longer necessary for navigation, which opened up new food sources. Toothed whales
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