Sidwell (2009–2015) thumb|right|upright=1.81|Paul Sidwell and Roger Blench propose that the Austroasiatic phylum dispersed via the Mekong River drainage basin. Paul Sidwell (2009), in a lexicostatistical comparison of 36 languages which are well known enough to exclude loanwords, finds little evidence for internal branching, though he did find an area of increased contact between the Bahnaric and Katuic languages, such that languages of all branches apart from the geographically distant Munda and Nicobarese show greater similarity to Bahnaric and Katuic the closer they are to those branches, without any noticeable innovations common to Bahnaric and Katuic.
Sidwell (2009–2015) thumb|right|upright=1.81|Paul Sidwell and Roger Blench propose that the Austroasiatic phylum dispersed via the Mekong River drainage basin. Paul Sidwell (2009), in a lexicostatistical comparison of 36 languages which are well known enough to exclude loanwords, finds little evidence for internal branching, though he did find an area of increased contact between the Bahnaric and Katuic languages, such that languages of all branches apart from the geographically distant Munda and Nicobarese show greater similarity to Bahnaric and Katuic the closer they are to those branches, without any noticeable innovations common to Bahnaric and Katuic.