Yinwum

Yinwum is an extinct Paman language formerly spoken on the Cape York Peninsula of Queensland, Australia, by the Yinwum people. It is unknown when it became extinct, but it was no longer spoken by the 1960s. Historically, it underwent some unusual phonological changes that are difficult to classify and understand in phonetic terms.

From Wikipedia · Yinwum dialect · CC BY-SA 4.0