1. Mauldin R. A. 1985. Foraminiferal biostratigraphy, paleoecology, and correlation of the Del Rio Clay (Cenomanian) from Big Bend National Park, Brewster County, Texas, to Cerro de Muleros area, Dona Ana County, New Mexico. Unpubl. M.S. thesis, University of Texas at El Paso, 89 p.
2. Clark W. B. 1892. Mesozoic Echinodermata of the United States. U.S. Geological Survey Bulletin 97, 30 p.
3. A Lower Cretaceous brittle-star from the northern Yukon Territory, Canada;Corgan;Journal of Paleontology,1962