Australia: The Land Where Time Began

A biography of the Australian continent 

The Vertebrate Head

The vertebrates have also been known as craniates, as all vertebrates have a head with specialised features - the cranium, the skull. There are a range of features that comprise the head of a vertebrate, such as the notochord, dorsal nerve cord, pharyngeal 'gill' slits, postanal tail and myomeres, etc. There are a number of characteristics of the vertebrate head that define a true head - the nose, eyes and ears, well defined sensory organs, all of which have all the necessary nerve connections, as well as the cranial nerves, included among the special features of vertebrates, the olfactory, optic and auditory (otic) regions that make up a true brain.

The brain is in the form of an expansion of the nerve cord at the leading end of the body in organisms such as amphioxus and sea squirts, and all the cell and sensory organ systems, though not all vertebrates have all of these developed to the same level.

Sources & Further reading

1. Benton, Michael J., 2005, Vertebrate Palaeontology, 3 rd ed., Blackwell Publishing.