Cope, K., Utgaard, J., Masters, J., & Feldmann, R. (2005). The Fauna of the Clayton Formation (Paleocene, Danian) of Southern Illinois: A Case of K/P Survivorship and Danian Recovery. Bulletin of the Mizunami Fossil Museum. https://oaks.kent.edu/node/1958
Cope, Kerri, John Utgaard, John Masters, and Rodney Feldmann. 2005. “The Fauna of the Clayton Formation (Paleocene, Danian) of Southern Illinois: A Case of K/P Survivorship and Danian Recovery”. Bulletin of the Mizunami Fossil Museum. https://oaks.kent.edu/node/1958.
Cope, K., J. Utgaard, J. Masters, and R. Feldmann. The Fauna of the Clayton Formation (Paleocene, Danian) of Southern Illinois: A Case of K/P Survivorship and Danian Recovery. Bulletin of the Mizunami Fossil Museum, 1 Jan. 2005, https://oaks.kent.edu/node/1958.