The title is click-baity (e.g. what's an "ancient language"?), but the content is still interesting regardless.

A few highlights:

Acc. to the author Great Andamanese ("GA") speakers have been culturally isolated from speakers of other languages for millenniums. It has been described as a dialect continuum, but it's being replaced by Hindi and showing clear signs of language death.

What's unusual about its usage of body parts in the grammar is not the usage itself, but its frequency and how it does it. Excerpts from the article:

If the blood emerged from the feet or legs, it was otei; internal bleeding was etei; and a clot on the skin was ertei. Something as basic as a noun changed form depending on location.

My breakthrough was to realize that the prefix e-, which originally derived from an unknown word for an internal body part, had over eons morphed into a grammatical marker signifying any internal attribute, process or activity. So the act of seeing, ole, being an internal activity, had to be eole. The same prefix could be attached to -bungoi, or “beautiful,” to form ebungoi, meaning internally beautiful or kind; to sare, for “sea,” to form esare, or “salty,” an inherent quality; and to the root word -biinye, “thinking,” to yield ebiinye, “to think.”