Ganoidei

Definitions

  • WordNet 3.6
    • n Ganoidei a group of mostly extinct primitive bony fishes characterized by armor-like bony scales
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Webster's Revised Unabridged Dictionary
    • n. pl Ganoidei (Zoöl) One of the subclasses of fishes. They have an arterial cone and bulb, spiral intestinal valve, and the optic nerves united by a chiasma. Many of the species are covered with bony plates, or with ganoid scales; others have cycloid scales.☞ They were numerous, and some of them of large size, in early geological periods; but they are represented by comparatively few living species, most of which inhabit fresh waters, as the bowfin, gar pike, bichir, Ceratodus, paddle fish, and sturgeon.
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Century Dictionary and Cyclopedia
    • ganoidei In Agassiz's system of classification, one of four orders into which the class of fishes was divided. It contained those which have ganoid scales or plates of an angular, rhomboidal, polygonal, or subcircular form, as distinguished from those with placoid, cycloid, or ctenoid scales. As thus framed by Agassiz, the ganoids were an artificial group, including siluroids, plectognaths, lophobranchs, and other teleost fishes. By Owen the Ganoidei were divided into two suborders, Lepidoganoidei and Placoganoidei. By later authors the group has been restricted and raised to the rank of a subclass.
    • ganoidei Hence In Müller's system, a subclass of fishes with muscular or multivalvular aortic bulb, free branchiæ, covered gill-cavity, and no optic chiasm, a spiral intestinal valve (sometimes rudimentary), and usually fulcra on one or more fins. It was divided by Müller into two orders: Chondrostei, with a cartilaginous skeleton, as the sturgeons and paddle-fishes, and Holostei, with bony skeleton, as the Polypteridæ, Lepidosteidæ, Amiidæ, and many extinct forms. Each one of the existing families of ganoids has been made the type of an order by late writers. Thus, the sturgeons (Acipenseridæ) typify the order Chondrostei in a restricted sense, or Glaniostomi; the paddle-fishes (Polyodontidæ or Spatulariidæ), the order Selachostomi; the bichirs (Polypteridæ), the order Crossopterygia or Actinistia; the bony pikes or gars (Lepidosteidæ), the order Rhomboganoidei or Ginglymodi; and the bowfins (Amiidæ), the order Cycloganoidei or Halecomorphi. Besides these there are three extinct orders, Aeanthodini, Placodermi, and Pycnodontini. The ganoids abounded in former geologic periods, as far back as the Silurian; but the few above named are the only extant types. See ganoid, n. Also Ganoidea.
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Etymology

Webster's Revised Unabridged Dictionary
NL. See Ganoid

Usage

In literature:

Other orders are the Elasmobranchii or fishes without a bony skeleton, Ganoidei, and a small order called the Holocephali.
"Fast Nine" by Alan Douglas
The Teleostei must, moreover, have sprung from Ganoidei in which the vasa efferentia had become aborted.
"The Works of Francis Maitland Balfour, Volume 1" by Francis Maitland Balfour
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