The Macdonald Primate

Type material from Macdonald 1963

This week is rapidly turning into a week dedicated to not only the Sioux language and its influence on paleontology, but also J. R. Macdonald. We have done weeks like that in the past, but it is not necessarily what we are doing this week; it just happens that the animals we are describing this week were named by Macdonald. Today we are discussing one of the only fossil primates known from North America; this excludes primates of Central America. Ekgmowechashala, meaning "Little cat man" in Sioux, is a genus of 5 lb lemur-like primates standing approximatel one foot tall. Macdonald's etymology guide in the description shows that the pronounciationis  Igg-uh-moo Wee-chah-shah-lah. Living during the Late Oligocene and Early Miocene, Ekgmowechashala consisted of two species, E. philotau Macdonald, 1963 and E. zancanellai Samuels, et al. 2015. The genus has been contentious since the type species was described by Macdonald in 1963, but a recent phylogenetic study by Ni, et al. (2016) solidified the phlyogenetic position of Ekgmowechashala as a member of the group Adapiformes, the extinct relatives of lemurs and other basal primates. Adapiformes are some of the most basal members of the primate family tree. The teeth of Ekgmowechashala represent the majority of the originally known material and allowed for inferences of diet. The diet of Ekgmowechashala is thought to have consisted of soft fruits from the warm forests of the Oligocene-Miocene.

Warm forests are not the typical scene for the Rocky Mountains, but during the time of Ekgmowechashala the mountains of western North America were warmer than they are now. The teeth leading to this inference make up a large majority of the fossil material that has been recovered. Teeth have been recovered from the 1960's to the present day from Shannon Count, South Dakota (type material), Pine Ridge and Oglala Sioux reservations in South Dakota, Oregon, Nebraska, and Texas. Ekgmowechashala zancanellai material comes from Oregon exclusively at the moment whereas the type species consists of material from the remaining localities.