Austroasiatic speakers dispersed rapidly via waterways, they would have encountered speakers of older language families who were already settled in the area, such as Sino-Tibetan. Sidwell (2018) Sidwell (2018) (quoted in Sidwell 2021) gives a more nested classification of Austroasiatic branches as suggested by his computational phylogenetic analysis of Austroasiatic languages using a 200-word list. Many of the tentative groupings are likely linkages. Pakanic and Shompen were not included. Possible extinct branches Roger Blench (2009) also proposes that there might have been other primary branches of Austroasiatic that are now extinct, based on substrate evidence in modern-day languages. Pre-Chamic languages (the languages of coastal Vietnam before the Chamic migrations). Chamic has various Austroasiatic loanwords that cannot be clearly traced to existing Austroasiatic branches (Sidwell 2006, 2007). Larish (1999) also notes that Moklenic languages contain many Austroasiatic loanwords, some of which are similar to the ones found in Chamic. Acehnese substratum (Sidwell 2006). Acehnese has many basic words that are of Austroasiatic origin, suggesting that either Austronesian speakers have absorbed earlier Austroasiatic residents in northern Sumatra, or that words might have been borrowed from Austroasiatic languages in southern Vietnam – or perhaps a combination of both. Sidwell (2006) argues that Acehnese and Chamic had often borrowed Austroasiatic words independently of each other, while some Austroasiatic words can be traced back to Proto-Aceh-Chamic. Sidwell (2006) accepts that Acehnese and Chamic are related, but that they had separated from each other before Chamic had borrowed most of its Austroasiatic lexicon. Bornean substrate languages (Blench 2010). Blench cites Austroasiatic-origin words in modern-day Bornean branches such as Land Dayak (Bidayuh, Dayak Bakatiq, etc.), Dusunic (Central Dusun, Visayan, etc.), Kayan, and Kenyah, noting especially resemblances with Aslian. As further evidence for his proposal, Blench also cites ethnographic evidence such as musical instruments in Borneo shared in common with Austroasiatic-speaking groups in mainland Southeast Asia. Adelaar (1995) has also noticed phonological and lexical similarities between Land Dayak and Aslian. Kaufman (2018) presents dozens of lexical comparisons showing similarities between various Bornean and Austroasiatic languages. Lepcha substratum ("Rongic"). Many words of Austroasiatic origin have been noticed in Lepcha, suggesting a Sino-Tibetan superstrate laid over an Austroasiatic substrate. Blench (2013) calls this branch "Rongic" based on the Lepcha autonym Róng. Other languages with proposed Austroasiatic substrata are: Jiamao, based on evidence from the register system of Jiamao, a Hlai language (Thurgood 1992). Jiamao is known for its highly aberrant