Dolphins: A language
Dolphins produce a great variety of other noises quite apart from ultra sounds and there has been considerable speculation as to whether these sounds constitute a language. So far, we have identified some twenty different sounds that dolphins make. Some seem to serve to keep a school together when they are travelling at speed, other appears to be warning cries. But no one yet has demonstrated that dolphins ever put these sounds together to form the equivalent of the two word sentence that can justifiably be regarded as the beginning of true language, a phenomenon already demonstrated for Chimpanzees (Pan troglodytes).