ostracoderm (redirected from Ostracoderms)

os·tra·co·derm  (str-k-dûrm)

n.

Any of several groups of extinct primitive jawless fishes of the Ordovician through the Devonian periods in North America and Europe, having bodies that were encased in an armor of bony plates.

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[Greek ostrakon, shell; see ost- in Indo-European roots + -derm.]

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ostracoderm  (str-k-dûrm)

Any of three orders of small, extinct primitive jawless fishes of the Ordovician through the Devonian Period. Most ostracoderms had their heads or entire bodies encased in fused bony plates. Some or all ostracoderms are sometimes classified together with the modern cyclostomes (lampreys and hagfish).

Thesaurus

Noun

1.

ostracoderm - extinct fish-like jawless vertebrate having a heavily armored body; of the Paleozoic 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