Chono is a poorly attested extinct language of confusing classification that may or may not be related to Kawesqar

Kawésqar language

Kawésqar is an Alacalufan language spoken in southern Chile by the Kawésqar people. Originally there were several distinct dialects...

. It is attested primarily from an 18th-century catechism, which is not translated into Spanish. Viegas Barros, who postulates a relationship between Kawesqar and Yaghan

Yaghan language

Yagán , also known as Yámana and Háusi Kúta, is one of the indigenous languages of Tierra del Fuego, spoken by the Yagán people...

, believes that 45% of the Chono vocabulary and grammatical forms correspond to one of those languages, though it is not close to either.