This mentioned taxonomy is an attempt to make an conclusive assignment from the different classifications of various scientists. Because the taxonomy may change due to the latest investigative methods and other findings, our map is a guide only.
Corresponding author (Name, Year)
Ref.: E. D. Cope. 1875. Check-list of North American Batrachia and Reptilia; with a systematic list of the higher groups, and an essay on geographical distribution. Based on the specimens contained in the U. S. National Museum. Bulletin of the United States Nat
D. Parmley, 2010 - Fossil snakes of the Clarendonian (late Miocene) Pratt Slide local fauna of Nebraska, with the description of a new natricine colubrid - Journal of Herpetology (44), 526-543 (journal article, English)
D. Parmley, 1995 - Hemphillian (late Miocene) snakes from Nebraska, with comments on Arikareean through Blancan snakes of midcontinental North America - Journal of Vertebrate Paleontology (15), 79-95 (journal article, English)
J. L. Behler, 1979 - - National Audubon Society Field Guide to Reptiles and Amphibians: North America (), 1-743 (book/book chapter, English)