C. vellerosus is generally known from the Chaco region of Bolivia (CuÃ©llar and Noss 2003, Noss et al. 2008), Paraguay and Argentina (Gardner 2005). A disjunct population occurs in eastern Buenos Aires Province, Argentina (Crespo 1974, Carlini and VizcaÃno 1987, Abba et al. 2007, Abba 2008, Abba and Cassini 2008). Records from Chile are probably Chaetophractus nationi.