Synonyms: Cyclopidius brevifacies Cope 1877, Hadroleptauchenia primitiva Schultz and Falkenbach 1968, Leptauchenia brevifacies Cope 1877, Leptauchenia harveyi Schultz and Falkenbach 1968, Pithecistes breviceps Loomis 1925, Pithecistes brevifacies Cope 1877, Pithecistes facies Cope 1888, Pithecistes tanneri Schultz and Falkenbach 1968, Pseudocyclopidius frankforteri Schultz and Falkenbach 1968
Full reference: J. Leidy. 1856. Notice of remains of extinct Mammalia, discovered by Dr. F. V. Hayden in Nebraska Territory. Proceedings of the Academy of Natural Sciences of Philadelphia 8:88-90
- Leptauchenia decora: Its type locality is Eagle Nest Butte (Brule), which is in an Arikareean terrestrial horizon in the Brule Formation of South Dakota
- Hadroleptauchenia primitiva: Its type locality is Hay Creek, which is in a Whitneyan terrestrial horizon in the Brule Formation of South Dakota.
- Leptauchenia harveyi: Its type locality is UNSM Sx-15 (Whitney A), which is in a Whitneyan terrestrial horizon in the Brule Formation of Nebraska.
- Pithecistes breviceps:
- Pithecistes brevifacies:
- Pithecistes facies:
- Pithecistes tanneri:
- Pseudocyclopidius frankforteri:
Ecology: ground dwelling herbivore
Average measurements (in mm): m1 8.90 x 6.50, m2 10.0 x 7.0, m3 18.0 x 7.0