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See also: agnatha


Agnatha, such as this lamprey, are distinguished by the lack of a jaw.


From Ancient Greek ἀ- (a-, without) + γνάθος (gnáthos, jaw).

Proper noun[edit]


  1. The jawless fishes, or agnathans
    1. A taxonomic superclass within the subphylum Vertebrata.
      • 1889, Edward Drinker Cope, "Synopsis of the Families of Vertebrata", The American Naturalist, volume 23, page 852:
        The known members of the class Agnatha are a very small representation of those that once existed; and they present a great variety of character, having little affinity with each other.
      • 2007, Chad Thomas et al., Freshwater Fishes of Texas, Texas A&M University Press, page 6:
        Current classification schemes have living fishes assigned to two superclasses (Agnatha, or jawless chordates, and Gnathostomata, or jawed chordates)[…].
    2. A taxonomic infraphylum within the subphylum Vertebrata.[1]




See also[edit]

Coordinate terms[edit]


Further reading[edit]


  1. ^ Ruggiero MA, Gordon DP, Orrell TM, Bailly N, Bourgoin T, Brusca RC, et al. (2015) A Higher Level Classification of All Living Organisms. PLoS ONE 10(4): e0119248. doi: 10.1371/journal.pone.0119248. pmid:25923521