jawless vertebrate

Thesaurus

Noun

1.

jawless vertebrate - eel-shaped vertebrate without jaws or paired appendages including the cyclostomes and some extinct formsagnathan, jawless fishaquatic vertebrate - animal living wholly or chiefly in or on waterAgnatha, superclass Agnatha - superclass of eel-shaped chordates lacking jaws and pelvic fins: lampreys; hagfishes; some extinct formsostracoderm - extinct fish-like jawless vertebrate having a heavily armored body; of the Paleozoicheterostracan - extinct jawless fish with the anterior part of the body covered with bony plates; of the Silurian and Devoniancephalaspid, osteostracan - extinct jawless fish of the Devonian with armored headanaspid - extinct small freshwater jawless fish usually having a heterocercal tail and an armored head; of the Silurian and Devonianconodont - small (2 inches long) extinct eellike fish with a finned tail and a notochord and having cone-shaped teeth containing cellular bone; late Cambrian to late Triassic; possible predecessor of the cyclostomescyclostome - primitive aquatic vertebratelamper eel, lamprey, lamprey eel - primitive eellike freshwater or anadromous cyclostome having round sucking mouth with a rasping tonguehagfish, slime eels, hag - eellike cyclostome having a tongue with horny teeth in a round mouth surrounded by eight tentacles; feeds on dead or trapped fishes by boring into their bodies