Chordate of the three subdivisions of chordates, all have distinct skulls. They include the hagfish, which have no vertebrae. Michael J. Benton commented that "craniates are characterized by their heads, just as chordates, or possibly all deuterostomes, are by their tails". Most craniates are vertebrates, in which the notochord is replaced by the vertebral column. These consist of a series of bony or cartilaginous cylindrical vertebrae, generally with neural arches that protect the spinal cord, and with projections that link the vertebrae. However hagfish have incomplete braincases and no vertebrae, and are therefore not regarded as vertebrates, but as members of
Confronted animals are often treated in the same way, often mixed in with animals in decorative schemes - archers were especially popular in the Romanesque period. The early Anglo-Saxon ship burial found in contemporary Great Britain at Sutton Hoo, from the seventh century AD, contains famous examples of Migration Period art. The Sutton Hoo purse-lid has three stylized confronted-animal pairs; the two side pairs, left and right, are identical, and have the animals in the person's clutched grasp. The central confronted animals are even more complex in theme. Opposed animals are used in Insular art, the style of which is derived from