This is not the first time a hidden language, different from its neighbors, has come to light in a remote area.
But this one shows a unique situation. Two languages, spoken by distinct subgroups...yet both groups claim to be of the same ethnicity. The only known parallel would be speakers of ASL...a language forced on deaf people by circumstances.
In almost all cases, language becomes identity (In fact, some deaf parents refuse to allow their children to be fitted with cochlear implants because deafness, having its own language, has become an identity). Yet these people insist there is no difference between them.
There's an alien feel to this. I may have to do something with it.