roughtail vs shieldtail

roughtail

noun

  • A small snake of the family Uropeltidae. 

  • The roughtail stingray 

adj

  • Having a rough tail. 

shieldtail

noun

  • Any species of small burrowing snakes of the family Uropeltidae, native to Sri Lanka and Southern Asia. 

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