placoderm

As nouns the difference between placoderm and ptyctodontid

is that placoderm is a member of an extinct group of fish with armored heads; the group lived during the silurian and devonian periods while ptyctodontid is any placoderm of the order ptyctodontida .

As nouns the difference between placoderm and ptyctodont

is that placoderm is a member of an extinct group of fish with armored heads; the group lived during the silurian and devonian periods while ptyctodont is any placoderm of the order (taxlink) .

As nouns the difference between placoderm and phyllolepid

is that placoderm is a member of an extinct group of fish with armored heads; the group lived during the silurian and devonian periods while phyllolepid is (zoology) any extinct placoderm of the order .

As nouns the difference between placoderm and antiarch

is that placoderm is a member of an extinct group of fish with armored heads; the group lived during the silurian and devonian periods while antiarch is (zoology) any of a group of extinct placoderms of the order antiarchi .

Placoderm is a hypernym of arthrodire.

As nouns the difference between placoderm and arthrodire

is that placoderm is a member of an extinct group of fish with armored heads; the group lived during the silurian and devonian periods while arthrodire is (zoology) any member of the extinct order , armored jawed fishes that flourished in the devonian period.