predecessor vs progenitor

predecessor

noun
  • A model or type of machinery or device which precedes the current (or later) one. Usually used to describe an earlier, outdated model. 

  • One who precedes; one who has preceded another in any state, position, office, etc.; one whom another follows or comes after, in any office or position. 

  • A vertex having a directed path to another vertex 

progenitor

noun
  • A predecessor of something, especially if also a precursor or model. 

  • A forefather, any of a person's direct ancestors. 

  • A founder. 

  • An ancestral form of a species. 

  • Someone who originates something. 

  • An individual from whom one or more people (dynasty, tribe, nation...) are descended. 

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