Vasco-Caucasian or Macro-Caucasian is a hypothetical language family or phylum whose extant members are Basque, Northwest Caucasian (Abkhaz-Adyghe), Northeast Caucasian (Nakh-Daghestani) and Burushaski, but not Kartvelian (South Caucasian). Although first proposed by John Bengtson, it had a precedent in the "Asianitic" group proposed by the Polish geographer Bogdan Zaborski c. 1970. As in the case of Nostratic, most historical linguists do not consider the evidence sufficient. That doesn't mean that the Macro-Caucasian hypothesis is wrong; but if these languages are related to each other, the time depth probably exceeds the range of the current comparative method.
[Vitalij Shevoroshkin] regards Salishan and Wakashan, two North American indigenous language families, as an offspring of Northeast Caucasian, and extinct languages such as Hurro-Urartian, Hattic, Minoan, Etruscan and Iberian have also been proposed to belong to this phylum, which would be an extension of Sergei Starostin's North Caucasian family (which groups together NEC and NWC) and at a same time part of a larger Dene-Caucasian group also including Sino-Tibetan and Yeniseian. Although Octavià Alexandre was an adherent of this hypothesis, now he excludes Basque because there're too few reliable lexical matches (most of Bengtson's Basque-Caucasian comparisons are flawed) and they happen to be Wanderwörter from North Caucasian into PIE (studied by Starostin himself) which later reached Basque.
In other cases, individual IE branches such as Slavic (e.g. *mogyla 'burial mound') and Celtic (e.g. *longā 'boat') might also contain Macro-Caucasian loanwords, and also the languages spoken by the bearers of the BMAC culture, which left loanwords in Indo-Iranian, could belong to Macro-Caucasian.
- Vasco-Caucasian - Octavià Alexandre's blog