Proto-language
Much work has been done on the reconstruction of Proto-Mon–Khmer in Harry L. Shorto's Mon–Khmer Comparative Dictionary. Little work has been done on the Munda languages, which are not well documented; with their demotion from a primary branch, Proto-Mon–Khmer becomes synonymous with Proto-Austro-Asiatic.
Sidwell (2005) reconstructs the consonant inventory of Proto-Mon–Khmer as follows:
| *p | *t | *c | *k | *ʔ |
| *b | *d | *ɟ | *ɡ | |
| *ɓ | *ɗ | *ʄ | ||
| *m | *n | *ɲ | *ŋ | |
| *w | *l, *r | *j | ||
| *s | *h |
This is identical to earlier reconstructions except for *ʄ. *ʄ is better preserved in the Katuic languages, which Sidwell has specialized in. Sidwell (2011) suggests that the likely homeland of Austro-Asiatic is the middle Mekong, in the area of the Bahnaric and Katuic languages (approximately where modern Laos, Thailand, and Cambodia come together), and that the family is not as old as frequently assumed, dating to perhaps 4000 BCE.
Read more about this topic: Austro-Asiatic Languages