progenitor vs taxon

progenitor

noun
  • An ancestral form of a species. 

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

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

  • A founder. 

  • Someone who originates something. 

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

taxon

noun
  • A group of one or more populations of an organism or organisms seen by taxonomists to form a unit. 

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