Waitaká language
Waitaká (Guaitacá, Goyatacá, Goytacaz) is an extinct language of Brazil, on the São Mateus River and near Cabo de São Tomé in the state of Rio de Janeiro. Not a word of it is known. Dialects, or at least tribal divisions, were Mopi, Yacorito, Wasu, and Miri. Loukotka (1968) suggests it may have been one of the Purian languages, though others consider this classification "circumstantial".
Reconstruction
Operating under the assumption that Waitaká is a Purian language, Silva Neto (2007) reconstructs some words and a phonology.