The Arikapú and Djeoromitxí languages form a small linguistic family in southern Rondônia, known as Jabutí. The languages are highly endangered and high quality data have become available only recently. This article is intended to create a basis of evidence for Curt Nimuendajú's hypothesis that the Jabutí language family belongs to the Macro-Jê linguistic stock. After short descriptive sketches of both Jabutí languages and the historical and sociocultural background, the article focusses on the reconstruction of the ancestral language, Proto-Jabutí, following the principles of the historical-comparative method
Indigenous languages; Jabutí family; Historical reconstruction; Phonology; Morphosyntax; Macro-Jê stock
