Cuitlatec (alternatively Cuitlateco, Cuitlateca) was an indigenous ethnic group of Mexico's Pacific coast region, in the Río Balsas region of Guerrero state. As a linguistic group and ethnic identity Cuitlatec is considered extinct.
Their native language, also called Cuitlatec, is generally considered to be a language isolate.
References
Cuitlatec people Wikipedia(Text) CC BY-SA