Zygodiscus amphipons Bramlette and Martini, 1964
Bramlette, M. N. & Martini, E. (1964). The great change in calcareous nannoplankton fossils between the Maastrichtian and Danian. Micropaleontology. 10(2): 291-322.
Gartner, S., (1968): Coccoliths and related calcareous nannofossils from Upper Cretaceous deposits of Texas and Arkansas. - University of Kansas Paleontological Contributions, Articles. 48 (Protista 1): 1-56.