Mammalia - Rodentia - Cricetidae

Alternative combinations: Cotimus blacki, Eumys blacki

Full reference: J. R. Macdonald. 1963. The Miocene faunas from the Wounded Knee area of western South Dakota. Bulletin of the American Museum of Natural History 125(3):139-238

Belongs to Leidymys according to L. D. Martin 1980

Sister taxa: Leidymys alicae, Leidymys azybaevi, Leidymys cerasus, Leidymys korthi, Leidymys lockingtonianus, Leidymys nematodon, Leidymys parvus

Type specimen: Its type locality is Sharps (SDSM V-5362), which is in a Geringian terrestrial horizon in the Sharps Formation of South Dakota

Ecology: ground dwelling herbivore

Average measurements (in mm): m1 2.06 x 1.48

Estimated body mass: 45.0 g based on m1 length