Noun: placoderm 'pla-ku,durm or 'pla-kow,durm
- Fish-like vertebrate with bony plates on head and upper body; dominant in seas and rivers during the Devonian; considered the earliest vertebrate with jaws
"Placoderms were the first jawed vertebrates to appear in the fossil record"
Derived forms: placoderms
Type of: aquatic vertebrate
Part of: class Placodermi, Placodermi
Encyclopedia: Placoderm