Claim: Tapayuna language is a Northern Je language spoken in Mato Grosso, Brazil by the Tapayuna people who historically have lived on the Arinos River.
Evidence: Tapayúna (Kajkwakhrattxi or Kajkwakhratxi, also spelt Tapajúna, Tapayúna: Kajkwakhrattxi kawẽrẽ [kajkʰwakʰʀ̥atˈtʃi kaˈw̃ẽɾẽ]) is a Northern Jê language (Jê, Macro-Jê) spoken in Mato Grosso, Brazil by the Tapayúna (Kajkwakhrattxi) people. The Tapayuna historically lived on the Arinos River, in the Tapajós basin, between Juruena and Aripuanã.