ostracoderms From WikiWord, the free dictionary English Contents DefinitionsRelated wordsReferences DefinitionsnounAny of the armored jawless fishes of the Paleozoic. Related wordsSynonymsjawlessostracodostracodaopisthobranchsechinodermsostraconostracaosteichthyesopisthobranchiaprotostomeostrichanostracaorthoceraschilopodaechinoidoestridae References Wiktionary — ostracoderms Wikipedia — ostracoderms