Hamm, S.A. (2008)
Systematic, stratigraphic, geographic, and paleoecological distribution of the Late Cretaceous shark genus Ptychodus within the Western Interior Seaway. Unpublished MS thesis, University of Texas, Dallas, 434 pp
Hamm, S.A. (2015)
Paraptychodus washitaensis n. gen. et n. sp., of Ptychodontid shark from the Albian of Texas, USA. Cretaceous Research, 54, 60–67
DOI: 10.1016/j.cretres.2014.10.015
Hamm, S.A. (2020)
Stratigraphic, Geographic, and Paleoecological Distribution of the Late Cretaceous Shark Genus Ptychodus within the Western Interior Seaway, North America. New Mexico Museum of Natural History and Science, Bulletin, 81, 1–94