Literature
- Gaffney, E. S. 1975a. Phylogeny of the chleydrid turtles: a study of shared derived characters in the skull. Fieldiana: Geol. 33: 157-178.
- Gray, J. E. 1869a. Notes on the families and genera of tortoises (Testudinata), and on the characters afforded by the study of their skulls. Proc. Zool. Soc. London 1869: 165-225.
- Haiduk, M. W., and J. W. Bickham. 1982. Chromosomal homologies and evolution of testudinoid turtles with emphasis on the systematic placement of Platysternon. Copeia.
- Romer, A. S. 1956. Osteology of the reptiles. Univ. Chicago Press, Chicago, Illinois. 772 pp.
- Shaffer, H. B., P. Meylan, and M. L. McKnight. 1997. Tests of turtle phylogeny: molecular, morphological and paleontological approaches. Syst. Biol. 46: 235-268.
- Whetstone, K. N. 1978. Additional record of the fossil snapping turtle Macroclemys schmidti from the Marshland Formation (Miocene) of Nebraska with notes on interspecific skull variation within the genus Macroclemys. Copeia.