Definition of ostracoderm in English:


Line breaks: os¦traco|derm
Pronunciation: /ɒˈstrakədəːm


  • An early jawless fossil fish of the Cambrian to Devonian periods, having a heavily armoured body.
    • Class Agnatha: several orders
    More example sentences
    • By the Middle Devonian the armoured jawless ostracoderms were in decline, and instead the jawed fish were undergoing a great evolutionary radiation in both the sea and in freshwater.
    • With their armored head shield and trunk shield composed of overlapping bony plates, the placoderms appear at first glance extremely similar to the ostracoderms (armoured jawless fish).
    • These were jawless, armored fish informally called ostracoderms, but more correctly placed in the taxon Pteraspidomorphi.


late 19th century: from modern Latin Ostracodermi (former taxonomic name), from Greek ostrakon 'shell' + derma 'skin'.

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grotesque quality or grotesque things collectively