vertebrates

ver*te*brate

noun

{bc}any of a subphylum (Vertebrata) of chordates that comprises animals (such as mammals, birds, reptiles, amphibians, and fishes) typically having a bony or cartilaginous spinal column which replaces the {d_link|notochord|notochord}, a distinct head containing a brain which arises as an enlarged part of the {d_link|nerve cord|nerve cord}, and an internal usually bony skeleton and that includes some primitive forms (such as {d_link|lampreys|lamprey}) in which the spinal column is absent and the notochord persists throughout life