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
Spade-toothed whale small fish. The young probably become independent of their mothers at about one year of age, as is the case in most whales. The population status of the spade-toothed whale is entirely unknown, but it is unlikely to be abundant. The spade-toothed whale is covered by the Memorandum of Understanding for the Conservation of Cetaceans and Their Habitats in the Pacific Islands Region (Pacific Cetaceans MOU). The sex of the 20th-century specimens is not known. By recovering or failing to recover DNA sequences of the Y chromosome, it could, in theory, be resolved. Little material is shared between the Pitt