Rossmann 1999. "Crotaphytus" oligocenicus (Holman, 1972), (Squamata: Iguanoides) from the Oligocene of Saskatchewan, reinterpretation and some paleobiogeographical implications. Neues Jahrbuch fuer Geologie und Palaeontologie Monatshefte, 3, Marz 1999: 186-192