Lewis, S. 1987. Fossil ants (Hymenoptera: Formicidae) from the Ruby River Basin (Oligocene) of southwestern Montana. Occasional Papers in Paleobiology. St. Cloud State University 1(3):1-10.

Notes: Tentative generic identifications: Camponotus, Elaeomyrmex, Lasius, Liometopum, and Protazteca.