Sioux language
The earlier linguistic three-way division of the Sioux language identified "Lakota", "Dakota", and "Nakota" as varieties of a single language, where Lakota = Teton, Dakota = Santee-Sisseton and Nakota = Yankton-Yanktonai. However, the latest studies show that Yankton-Yanktonai never used the autonym "Nakhóta", but pronounced their name roughly the same as the Santee (i.e. "Dakȟóta").