Mammalia - Rodentia - Allomyidae

Synonyms: Allomys sharpi Macdonald 1970, Downsimus sharpi Macdonald 1970

Full reference: J. R. Macdonald. 1970. Review of the Miocene Wounded Knee faunas of southwestern South Dakota. Bulletin of the Los Angeles County Museum of Natural History, Science 8:165-82

Belongs to Downsimus according to J. R. Macdonald 1970

Sister taxa: none

Type specimens:

• Downsimus chadwicki: Its type locality is Sharps (SDSM V-544), which is in a Geringian terrestrial horizon in the Sharps Formation of South Dakota
• Allomys sharpi: Its type locality is Sharps (SDSM V-5361), which is in a Geringian terrestrial horizon in the Sharps Formation of South Dakota.

Ecology: ground dwelling herbivore

Average measurements (in mm): M1 1.82 x 2.63, M2 1.82 x 2.63, M3 1.38 x 1.68, m1 1.83 x 1.56, m2 1.90 x 1.57, m3 2.62 x 1.97