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
Transportation of animals Transportation of animals The transportation of animals is the intentional movement of animals by transport. Common categories of animals which are transported include livestock destined for sale or slaughter; zoological specimens; laboratory animals; race horses; pets; and wild animals being rescued or relocated. Methods of transporting animals vary greatly from species to species. Humans have been transporting animals for a variety of purposes for thousands of years, with numerous accounts of animal transportation from the ancient world. Animals were transported for Roman circuses and for use as military animals. Two well-known historical examples of animals transported to foreign countries are