Chaco linguistic area

The Chaco linguistic area is a linguistic area that includes various South American language families and isolates of the Chaco region of South America, in southern Brazil, southeastern Bolivia, Paraguay, Uruguay, and Argentina.
Common Chaco areal features include SVO word order and active-stative verb alignment.

Languages

Campbell and Grondona list the following languages as part of the Chaco linguistic area.

Charruan is sometimes also included. Jorge Suárez includes Charruan with Guaicuruan in a hypothetical Waikuru-Charrúa stock. Morris Swadesh includes Charruan along with Guaicuruan, Matacoan, and Mascoyan within his Macro-Mapuche stock. Both proposals appear to be obsolete.
Jolkesky suggests that Trumai has lexical similarities with the Macro-Mataguayo-Guaykuru and Tupian language families. These apparent similarities with the Macro-Mataguayo-Guaykuru languages and Tupi-Guarani languages suggest that Trumai had originated in the Paraguay River basin. The Trumai had only arrived in the Upper Xingu basin via the Culuene River during the 19th century.
The following language families of the Argentinian Pampas are also included in some classifications.

Linguistic features that are characteristic of the Chaco linguistic area include:

gender that not overtly marked on nouns, but is present in demonstratives, depending on the gender of the nouns modified
genitive classifiers for possessed domestic animals
SVO word order
active-stative verb alignment
large set of directional verbal affixes
demonstrative system with rich contrasts including visible vs. not visible
some adjectives as polar negatives
resistance to borrowing foreign words

Nikulin suggests a Macro-Chaco hypothesis linking Jê-Tupí-Cariban with Mataco-Guaicuruan :