formation | Pekin | Command (military formation) | Elliot Formation | Lance Formation | Crato Formation | Chinle Formation | Two Medicine Formation | Tamayama Formation | Missing Man Formation (band) | Missing Man Formation | Marcellus Formation | Kirkwood Formation | Gettysburg Formation | Clarens Formation | Whitby Mudstone Formation | Tunbridge Wells Sand Formation | Santana Formation | Phalanx formation | phalanx formation | Pekin, Illinois | Mahantango Formation | Leduc Formation | Identity formation | Hanson Formation | Formation (stratigraphy) | formation (stratigraphy) | Formation | Centre International de Formation Européenne | Bakken formation |
The type series of R. olseni was thought to originate from the Pekin Formation of Montgomery County.