Definition of Agnatha in English:


plural noun


    Compare with cyclostome
    • ‘By the mid 1970s, insulin had been isolated and sequenced from all classes of vertebrates, including Agnatha.’
    • ‘The earliest fossil vertebrates belong to a group called the Agnatha or jawless vertebrates.’
    • ‘All of these jawless fish are traditionally placed in the order Agnatha, but as you can see, this group is paraphyletic, including some but not all descendants of the common ancestor.’


From modern Latin Agnatha, from a- ‘without’ + Greek gnathos jaw.