Proto-Eskimo–Aleut was the common ancestor of the Eskimo languages and Aleut. Its existence is known through similarities in Eskimo and Aleut. The existence of Proto-Eskimo–Aleut is generally accepted among linguists. It was for a long time true that no linguistic reconstruction of Proto-Eskimo–Aleut had yet been produced, as stated by Bomhard (2008:209). Such a reconstruction was offered by Knut Bergsland in 1986. Michael Fortescue (1998:124-125) has offered another version of this system, largely based on the reconstruction of Proto-Eskimo in the Comparative Eskimo Dictionary he co-authored with Steven Jacobson and Lawrence Kaplan (1994:xi).