Dené–Caucasian languages
Dené–Caucasian is a discredited language family proposal that includes widely-separated language groups spoken in the Northern Hemisphere: Sino-Tibetan languages, Yeniseian languages and Burushaski in Asia; Na-Dené languages in North America; as well as Vasconic languages (including Basque) and North Caucasian languages from Europe. A narrower connection specifically between North American Na-Dené and Siberian Yeniseian (the Dené–Yeniseian languages hypothesis) was proposed by Edward Vajda in 2008, and was met with some acceptance within the community of professional linguists.