what distinguishes the super classes agnatha and gnathostomata
Agnatha Agnatha (Greek,[3] "no jaws") is a superclass of jawless fish in the phylum Chordata, subphylum Vertebrata, consisting of both present (cyclostomes) and extinct (conodonts and ostracoderms) species. The group is sister to all vertebrates with jaws, known as gnathostomes.[4]