Before 1850, there were an estimated 500 to 600 Teushen people. They were slaughtered in the Argentinian genocides of Patagonia, known as the Conquest of the Desert. By 1925, only ten to twelve Teushen survived. They are considered extinct as a tribe.
The Teushen language is almost entirely unknown. Linguists believe, from the limited data available, that it was closest to Tehuelche, the language of the people to the south of the Teushen.