the family as a whole. The following tree of Kra–Dai is from Norquest (2007:16). Kra–Dai Northern Kra Northeastern Lakkia Kam–Sui Southern Hlai Be–Tai Tai Be Additionally, Norquest (2007) also proposes a reconstruction for Proto-Southern Kra–Dai. Norquest (2015, 2020) A revised Kra-Dai phylogenetic tree by Norquest (2015, 2020) is provided as follows. Kra–Dai Kra Eastern Kra-Dai Biao Lakkja-Kam-Tai Lakkja Kam–Tai Kam–Sui Western Kam-Tai Hlai Be-Tai Ong-Be Tai Hypotheses regarding external relationships Austro-Tai Several scholars have presented evidence that Kra–Dai may be related to, or even be a branch of the Austronesian language family. There are a number of possible cognates in the core vocabulary displaying regular sound correspondences. Among proponents, there is yet no agreement as to whether they are a sister group to Austronesian in a family called Austro-Tai, a back-migration from Taiwan to the mainland or a later migration from the Philippines to Hainan during the Austronesian expansion. The inclusion of Japanese in the Austro-Tai family, as proposed by Paul K. Benedict in the late 20th century, is not supported by the current proponents of the Austro-Tai hypothesis. Sino-Tai The Kra–Dai languages were formerly considered to be part of the Sino-Tibetan family, partly because they contain large numbers of words that are similar to Sino-Tibetan languages. However, these words are seldom found in all branches of the family and do not include basic vocabulary, indicating that they are old loan words. Outside China, the Kra–Dai languages are now classified as an independent family. In China, they are called Zhuang–Dong languages and are generally included, along with the Hmong–Mien languages, in the Sino-Tibetan family. It is still a matter of discussion among Chinese scholars whether Kra languages such as Gelao, Qabiao and Lachi can be included in Zhuang–Dong, since they lack the Sino-Tibetan similarities that are used to include other Zhuang–Dong languages in Sino-Tibetan. Hmong-Mien Kosaka (2002) argued specifically for a Miao–Dai family. He argues that there is much evidence for a genetic relation between Hmong–Mien and Kra–Dai languages. He further suggests that similarities between Kra–Dai and Austronesian are because of later areal contact in coastal areas of Eastern and Southeastern China or an older ancestral relation (Proto-East Asian). Japonic Vovin (2014) proposed that the location of the Japonic Urheimat (linguistic homeland) is in Southern China. Vovin argues for typological evidence that Proto-Japanese may have been a monosyllabic, SVO syntax and isolating language, which are also characteristic of Tai–Kadai languages.