caudal vs coccygeal vertebra

caudal

noun
  • A caudal vertebra. 

adj
  • Toward the tail end (hind end) of the body; in bipeds such as humans, this direction corresponds to inferior. 

  • Pertaining to the tail or posterior or hind part of a body. 

coccygeal vertebra

noun
  • Any of the four vertebrae that are found in the human coccyx. 

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