This biozone is characterized by the presence of Pristerognathus polyodon and its other subspecies Pristerognathus baini and Pristerognathus vanderbyli. Pristerognathus fossils are usually found associated with those of Diictodon.
The biozone is identified by the presence of Pristerognathus polyodon and its related species, Pristerognathus baini and Pristerognathus vanderbyli. These fossils are commonly discovered in association with Diictodon remains.