Nowadays, 16 of the human cultures existing when the conquistadors arrived are now considered to be extinct :

Atacamas
Diaguitas
Omaguacas
Tonocotés
Comechingones
Sanavirones
Huarpes
Abipones
Lule-Vilelas
Pehuenches
Chaná-Timbúes
Charrúas
Caingang
Yámanas-Alakaluf
Selknam
Ona