pinniped vs pinniped mammal

pinniped

adj
  • Pertaining to or similar to such a mammal. 

noun
  • Any of various large marine mammals belonging to the superfamily (formerly considered a suborder) Pinnipedia comprising walruses, eared seals and earless seals. 

pinniped mammal

How often have the words pinniped and pinniped mammal occurred in a corpus of books? (source: Google Ngram Viewer )