class Placodermi vs class

class Placodermi and class both are nouns.

Word	Noun	Adjective	Verb	Adverb
class Placodermi	Yes	No	No	No
class	Yes	No	Yes	No

As nouns, class is a hypernym of class Placodermi; that is, class is a word with a broader meaning than class Placodermi:

class Placodermi (noun)	class (noun)
extinct group of bony-plated fishes with primitive jaws	education imparted in a series of lessons or meetings
	elegance in dress or behavior
	a collection of things sharing a common attribute
	people having the same social, economic, or educational status
	(biology) a taxonomic group containing one or more orders
	a body of students who are taught together
	a body of students who graduate together
	a league ranked by quality

class Placodermi (verb)	class (verb)
	arrange or order by classes or categories