Craniata, subphylum Craniata, subphylum Vertebrata, Vertebrata - fishes; amphibians; reptiles; birds; mammals

agnathan, jawless fish, jawless vertebrate - eel-shaped vertebrate without jaws or paired appendages including the cyclostomes and some extinct forms

order Ostracodermi, Ostracodermi - extinct group of armored jawless vertebrates; taxonomy is not clear

Anaspida, order Anaspida - extinct order of jawless vertebrates

Conodonta, Conodontophorida, order Conodonta, order Conodontophorida - extinct order of primitive vertebrates; the precise taxonomy is not clear; in some classifications considered a separate phylum

Cyclostomata, order Cyclostomata - primitive jawless aquatic vertebrate: lampreys; hagfishes

class - (biology) a taxonomic group containing one or more orders