from The American Heritage® Dictionary of the English Language, 4th Edition

  • 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.

from Wiktionary, Creative Commons Attribution/Share-Alike License

  • 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

from the GNU version of the Collaborative International Dictionary of English

  • 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.

from The Century Dictionary and Cyclopedia

  • 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.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

  • 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


Greek nōton, back + chord2.
(American Heritage® Dictionary of the English Language, Fourth Edition)


  • 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.

    Haeckel had a point - The Panda's Thumb

  • A notochord is a rope of nervous connection which branches into the trunk nerves of the body.

    Neutron Star

  • Thus the notochord is the necessary forerunner of the vertebral column, cartilage the precursor of bone.

    Form and Function A Contribution to the History of Animal Morphology

  • The notochord is a continuous rod of cartilage, or gristle, which in the embryological growth of vertebrate animals supports the spinal nerve cord before the formation of the vertebrae.

    The Elements of Geology

  • The notochord is the supporting axis of the pioneer backboned animals, namely the Lancelets and the Round-mouths (Cyclostomes), such as the

    The Outline of Science, Vol. 1 (of 4) A Plain Story Simply Told

  • Concomitantly with the development of this canal, there is found, immediately beneath it, a little gelatinous rod enclosed in a membraneous envelope, and called the notochord, or chorda dorsalis.

    The Common Frog

  • Amphioxus has only a primitive proto-spinal column called a notochord, but it is a very close relative of vertebrates.

    NPR Topics: News

  • Amphioxus has only a primitive proto-spinal column called a notochord, but it is a very close relative of the vertebrates.

    NPR Topics: News

  • The finding is of particular relevance to the fossils of ancient chordates - animals that develop a characteristic rod-like support structure known as a notochord at some point during their lives.

    Scientific American

  • O. Mangold was able to show that mesodermal organs such as notochord, somites and pronephric ducts could arise from presumptive ectoderm by suitable transplantation at the beginning of gastrulation.

    Hans Spemann - Nobel Lecture


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  • "The notochord consists of a rod of cells situated on the ventral aspect of the neural tube; it constitutes the foundation of the axial skeleton, since around it the segments of the vertebral column are formed."
    - Henry Gray, 'Anatomy of the Human Body', 1918.

    September 20, 2009