Ernestokokenia

Ernestokokenia is an extinct genus of mammal, belonging to the Didolodontidae. It lived during the Early Eocene and the Middle Eocene, and its fossils were discovered in South America.

Description
This genus is only known from its teeth, and it is then impossible to reconstruct its exact appearance. From comparison with similar and better known animals such as Didolodus, its size is estimated between 60 centimeters and a meter long. Ernestokokenia was characterized by very simple molars and premolars, with a bunodont structure, similar to those of Didolodus. The upper third and fourth molar were differently shaped and lacked a mesostyle. The labial and lingual cingulum were well developed.

Classification
Ernestokokenia was a member of the Didolodontidae, an enigmatic clade of south-american mammals typicals of the early Cenozoic, of uncertain relationships. The first fossils of this animal were found in the Chubut Province in Patagonia (Argentina), in soils dated from the Middle Eocene, and were described by Florentino Ameghino in 1901. The type species is Ernestokokenia nitida. Ameghino described also Notoprotogonia patagonica and Euprotogonia trigonalis, later attributed to the genus by George Gaylord Simpson in 1948. In 1935, Simpson had described two other species, Ernestokokenia chaishoer and E. yurunhor, from the same Chubut Province, and from the Lower Eocene. Other fossils dubiously attributed to the genus have been found in soils of the Upper Paleocene of Argentina and the Eocene of Chile.