English Dictionary

placoderm

noun

(paleontology) A member of an extinct class (Placodermi) of jawed fish with armored heads and thoraces; the group lived during the Silurian and Devonian periods.

The placoderm was an ancient fish that lived during the Devonian period.

意味（1）

(paleontology) A member of an extinct class (Placodermi) of jawed fish with armored heads and thoraces; the group lived during the Silurian and Devonian periods.

Out to sea are placoderms – heavily armoured fish, some of them more than six metres (twenty feet) long and equipped with massive, powerful jaws.