PaleoDB taxon number: 203000
Full reference: O. P. Hay. 1904. On some fossil turtles belonging to the Marsh Collection in Yale University Museum. American Journal of Science, Fourth Series 18(106):261-276
Type specimen: YPM 299, a partial shell (Hay mentioned but did not figure carapace elements, but the type currently consists only of the plastron). Its type locality is south side of Lightning Creek, which is in a Maastrichtian terrestrial horizon in the Lance Formation of Wyoming.