pinniped mammal vs pinniped

pinniped mammal and pinniped both are nouns.

Word	Noun	Adjective	Verb	Adverb
pinniped mammal	Yes	No	No	No
pinniped	Yes	No	No	No

As nouns, pinniped mammal and pinniped are synonyms defined as:

pinniped mammal and pinniped: aquatic carnivorous mammal having a streamlined body specialized for swimming with limbs modified as flippers

Other synonyms of pinniped mammal include pinnatiped.

pinniped mammal (noun)	pinniped (noun)
aquatic carnivorous mammal having a streamlined body specialized for swimming with limbs modified as flippers	aquatic carnivorous mammal having a streamlined body specialized for swimming with limbs modified as flippers