Abstract The Random House Dictionary defines the word “neck” as “the part of the body of an animal or man that connects the head and the trunk.” Therefore, in classical terms, the neck would only be expected to happen in animals that have heads different from their trunks. Heads are expected to serve the organism in roles such as ingestion, mating, sensation, and defense. Trunks are expected to have roles in visceral function such as reproduction, digestion, circulation, and respiration. Other significant roles of trunks are transport, maintenance of posture, as well as attachment.