Quechumaran languages
Quechumaran is a language-family proposal that unites Quechua and Aymara. Quechuan languages, especially those of the south, share a large amount of vocabulary with Aymara. Terrence Kaufman finds the proposal reasonably convincing, but Willem Adelaar, a Quechua specialist, believes the similarities to be caused by borrowing during long-term contact. Lyle Campbell suspects that the proposal is valid but does not consider it to have been conclusively proved.