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n. A flexible rodlike structure that forms the main support of the body in the lowest chordates, such as the lancelet; a primitive backbone.

n. A similar structure in embryos of higher vertebrates, from which the spinal column develops.

n. A flexible rodlike structure that forms the main support of the body in the lowest chordates; a primitive spine

n. A similar structure found in the embryos of vertebrates from which the spine develops

n. An elastic cartilagelike rod which is developed beneath the medullary groove in the vertebrate embryo, and constitutes the primitive axial skeleton around which the centra of the vertebræ and the posterior part of the base of the skull are developed; the chorda dorsalis. See Illust. of ectoderm.

n. The chorda dorsalis or primitive backbone: a fibrocellular or cartilaginous rod-like structure which is developed in vertebrates as the basis of the future spinal column, and about which the bodies of the future vertebræ are formed.

n. A vestigial structure, representing a very ancient form of alimentary canal not in itself a part of the skeleton.

n. a flexible rodlike structure that forms the supporting axis of the body in the lowest chordates and lowest vertebrates and in embryos of higher vertebrates

"For example, the notochord is a character that provides internal structural support and unites all members of the phylum Chordata or chordates, animals with notochords and pharyngeal arches, among other characteristics."

vertebral column    spine    spinal column    rachis    back   

chorda dorsalis    ectoderm   

urochord   

backstrap    tegmental    hook-like    striatal    green-gray