*The Cervical, Clavicular and Cranial Thoracic air sacs form one functional group - '''Cranial''', with the Caudal Thoracic and Abdominal Air sacs forming another, '''Caudal''' functional group. | *The Cervical, Clavicular and Cranial Thoracic air sacs form one functional group - '''Cranial''', with the Caudal Thoracic and Abdominal Air sacs forming another, '''Caudal''' functional group. |