Bos primigenius vs aurochs

Bos primigenius

aurochs

noun
  • The European bison (Bison bonasus, or Europæus). 

  • An extinct European mammal, Bos primigenius, the ancestor of domestic cattle. 

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