Matter borrowing, pattern borrowing and typological rarities in the Gran Chaco of South America

The present paper explores the intersection between typological rarities, matter borrowing and pattern borrowing in the Gran Chaco of South America. In this region the only two living Zamucoan languages are spoken: Ayoreo and Chamacoco. Zamucoan has been for a long time in contact with the other languages of the area, in particular with the Guaycuruan and Mataguayan families. I analyze some rare features of Zamucoan, which developed through language contact or spread to neighboring languages. The reconstruction of Proto-Zamucoan permits us to understand better what has happened in terms of contact, or to figure out the development of rare characteristics involved in language contact: an example is Chamacoco clusivity, introduced via pattern borrowing. The formation of the Chamacoco first person plural exclusive is unusual; in addition, the pronominal system has acquired a split between a plural and a 'greater plural', a pattern borrowing from Niva& x109;le (Mataguayan). Some features spread from Chamacoco to Kadiweu (Guaycuruan), two languages with a well-documented story of contact. These are: (i) The affix order in the third person plural of Chamacoco verbs, where number prefix precedes person prefix; (ii) The marking of gender and number of possessive classifiers, found in the Kadiweu classifier for domestic animals. Other unusual features discussed here are voiceless nasals, para-hypotaxis and traces of egophoricity.