An indigenous language from South America’s extreme south has all but vanished after the death of its last living speaker and guardian of its ancestral culture.

Cristina Calderon died on Wednesday aged 93. She had mastered the Yamana language of the Yagan community and, after the death of her sister in 2003, was the last person in the world who could speak it. She worked to save her knowledge by creating a dictionary of the language with translations to Spanish.

“With her an important part of the cultural memory of our people is gone,” said Lidia Gonzalez, Calderon’s daughter, on Twitter. Gonzalez is one of the representatives at present drafting a new constitution in Chile...