| 释义 | agnathan
 ag·na·thanA0144300 (ăg′nə-thən)n. Any of various fishes lacking jaws, including the hagfishes and the lampreys and many extinct groups, such as the ostracoderms.[a- + Greek gnathos, jaw; see genu- in Indo-European roots + -an.]
 ag′na·than adj.
 agnathan(æɡˈneɪθən) n (Animals) any jawless eel-like aquatic vertebrate of the superclass Agnatha, which includes the lampreys and hagfishesadj (Zoology) of, relating to, or belonging to the superclass Agnatha. See also cyclostome[C19: from New Latin agnatha, from a-1 + Greek gnathos jaw]ThesaurusEncyclopediaSeeAgnatha| Noun | 1. |  agnathan - eel-shaped vertebrate without jaws or paired appendages including the cyclostomes and some extinct formsjawless fish, jawless vertebrateaquatic 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 | 
 agnathan
 agnathan(ăg′nə-thən)n. Any of various fishes lacking jaws, including the hagfishes and the lampreys and many extinct groups, such as the ostracoderms.ag′na·than adj.
 agnathanRelated to agnathan: Osteichthyes
 Synonyms for agnathannoun eel-shaped vertebrate without jaws or paired appendages including the cyclostomes and some extinct formsSynonymsjawless fishjawless vertebrate
 Related Wordsaquatic vertebrateAgnathasuperclass Agnathaostracodermheterostracancephalaspidosteostracananaspidconodontcyclostomelamper eellampreylamprey eelhagfishslime eelshag
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