WILLIAMSON, T.E. & KIRKLAND, J.I. & LUCAS, S.G. (1993)
Selachians from the Greenhorn cyclothem («Middle» Cretaceous: Cenomanian-Turonian), Black Mesa, Arizona, and the paleogeographic distribution of late Cretaceous selachians. Journal of Paleontology, 67 (3): 447–474, 15 fig.