Kumo Xi
Mongolian and other scholars have suggested that the Xiongnu spoke a language related to the Mongolic languages. Mongolian archaeologists proposed that the Slab Grave Culture people were the ancestors of the Xiongnu, and some scholars have suggested that the Xiongnu may have been the ancestors of the Mongols. According to the "Book of Song", the Rourans, whom Book of Wei identified as offspring of Proto-Mongolic Donghu people, possessed the alternative name(s) 大檀 "Dàtán" "Tatar" and/or 檀檀 "Tántán" "Tartar" and according to Book of Liang, "they also constituted a separate branch of the Xiongnu"; Nikita Bichurin considered Xiongnu and Xianbei to be two subgroups (or dynasties) of but one same ethnicity. However, Chinese chroniclers routinely ascribed Xiongnu origins to various nomadic groups: for examples, Xiongnu ancestry was ascribed to Turkic-speaking Göktürks and Tiele as well as Para-Mongolic-speaking Kumo Xi and Khitans.