fur seal vs otariid

fur seal

noun
  • A marine mammal of either of the genera Arctocephalus or Callorhinus of the eared seal family Otariidae, differing from the sea lions in having dense underfur. 

otariid

noun
  • Any member of the Otariidae, the eared seals 

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