[3] They differ from the former with a less curved root and finer serrations and from the latter with more prominent and recurved cusps.

Due to the subtle differences, it is sometimes lumped into O. auriculatus.

Due to its similarities with other chronospecies, it is difficult to tell exactly when it arose and went extinct.

Generally, it is said to span from the late Eocene to early Oligocene.

They are best known from the late Eocene localities around Dakhla, Morocco and Fayum, Egypt but are represented in many deposits of contemporary age.