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
Oh Dear! What Can the Matter Be? Oh Dear! What Can the Matter Be? "What Can the Matter Be?", also known as "Johnny's So Long at the Fair" is a traditional nursery rhyme that can be traced back as far as the 1770s in England. There are several variations on its lyrics. The "Oxford Dictionary of Nursery Rhymes" by Iona and Peter Opie traces this song back to an earlier folk ballad, recorded between 1770 and 1780, whose lyrics are: <poem> O what can the matter be And what can the matter be O what can the matter be Johnny bydes lang at the fair He'll buy