Protoprioniodus is an extinct genus of conodonts.
The Whiterock Stage refers mainly to the early Middle Ordovician in North America.
It is often used in the older literature in a global sense.
The Whiterock Stage is given a range from 471.8 (ca.
Officially its start is defined by the potentially lowest occurrence of the conodonts Protoprioniodus aranda or Baltoniodus triangularis.